Merge branch 'linus' into sched/core

Conflicts:
	fs/proc/array.c

Merge reason: resolve conflict and queue up dependent patch.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

97 files changed, 8993 insertions, 8402 deletions

diff --git a/kernel/Makefile b/kernel/Makefile
index 3d9c7e27e3f..b8d4cd8ac0b 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -58,7 +58,6 @@ obj-$(CONFIG_KEXEC) += kexec.o
 obj-$(CONFIG_BACKTRACE_SELF_TEST) += backtracetest.o
 obj-$(CONFIG_COMPAT) += compat.o
 obj-$(CONFIG_CGROUPS) += cgroup.o
-obj-$(CONFIG_CGROUP_DEBUG) += cgroup_debug.o
 obj-$(CONFIG_CGROUP_FREEZER) += cgroup_freezer.o
 obj-$(CONFIG_CPUSETS) += cpuset.o
 obj-$(CONFIG_CGROUP_NS) += ns_cgroup.o
@@ -87,7 +86,6 @@ obj-$(CONFIG_RELAY) += relay.o
 obj-$(CONFIG_SYSCTL) += utsname_sysctl.o
 obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o
 obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o
-obj-$(CONFIG_MARKERS) += marker.o
 obj-$(CONFIG_TRACEPOINTS) += tracepoint.o
 obj-$(CONFIG_LATENCYTOP) += latencytop.o
 obj-$(CONFIG_FUNCTION_TRACER) += trace/
@@ -96,7 +94,7 @@ obj-$(CONFIG_X86_DS) += trace/
 obj-$(CONFIG_RING_BUFFER) += trace/
 obj-$(CONFIG_SMP) += sched_cpupri.o
 obj-$(CONFIG_SLOW_WORK) += slow-work.o
-obj-$(CONFIG_PERF_COUNTERS) += perf_counter.o
+obj-$(CONFIG_PERF_EVENTS) += perf_event.o
 
 ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER),y)
 # According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is
diff --git a/kernel/audit.c b/kernel/audit.c
index defc2e6f1e3..5feed232be9 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -855,18 +855,24 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 		break;
 	}
 	case AUDIT_SIGNAL_INFO:
-		err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
-		if (err)
-			return err;
+		len = 0;
+		if (audit_sig_sid) {
+			err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
+			if (err)
+				return err;
+		}
 		sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
 		if (!sig_data) {
-			security_release_secctx(ctx, len);
+			if (audit_sig_sid)
+				security_release_secctx(ctx, len);
 			return -ENOMEM;
 		}
 		sig_data->uid = audit_sig_uid;
 		sig_data->pid = audit_sig_pid;
-		memcpy(sig_data->ctx, ctx, len);
-		security_release_secctx(ctx, len);
+		if (audit_sig_sid) {
+			memcpy(sig_data->ctx, ctx, len);
+			security_release_secctx(ctx, len);
+		}
 		audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_SIGNAL_INFO,
 				0, 0, sig_data, sizeof(*sig_data) + len);
 		kfree(sig_data);
diff --git a/kernel/audit_watch.c b/kernel/audit_watch.c
index 0e96dbc60ea..cc7e87936cb 100644
--- a/kernel/audit_watch.c
+++ b/kernel/audit_watch.c
@@ -45,8 +45,8 @@
 
 struct audit_watch {
 	atomic_t		count;	/* reference count */
-	char			*path;	/* insertion path */
 	dev_t			dev;	/* associated superblock device */
+	char			*path;	/* insertion path */
 	unsigned long		ino;	/* associated inode number */
 	struct audit_parent	*parent; /* associated parent */
 	struct list_head	wlist;	/* entry in parent->watches list */
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 68d3c6a0ecd..267e484f019 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -168,12 +168,12 @@ struct audit_context {
 	int		    in_syscall;	/* 1 if task is in a syscall */
 	enum audit_state    state, current_state;
 	unsigned int	    serial;     /* serial number for record */
-	struct timespec	    ctime;      /* time of syscall entry */
 	int		    major;      /* syscall number */
+	struct timespec	    ctime;      /* time of syscall entry */
 	unsigned long	    argv[4];    /* syscall arguments */
-	int		    return_valid; /* return code is valid */
 	long		    return_code;/* syscall return code */
 	u64		    prio;
+	int		    return_valid; /* return code is valid */
 	int		    name_count;
 	struct audit_names  names[AUDIT_NAMES];
 	char *		    filterkey;	/* key for rule that triggered record */
@@ -198,8 +198,8 @@ struct audit_context {
 	char		    target_comm[TASK_COMM_LEN];
 
 	struct audit_tree_refs *trees, *first_trees;
-	int tree_count;
 	struct list_head killed_trees;
+	int tree_count;
 
 	int type;
 	union {
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index c7ece8f027f..ca83b73fba1 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -23,6 +23,7 @@
  */
 
 #include <linux/cgroup.h>
+#include <linux/ctype.h>
 #include <linux/errno.h>
 #include <linux/fs.h>
 #include <linux/kernel.h>
@@ -48,6 +49,8 @@
 #include <linux/namei.h>
 #include <linux/smp_lock.h>
 #include <linux/pid_namespace.h>
+#include <linux/idr.h>
+#include <linux/vmalloc.h> /* TODO: replace with more sophisticated array */
 
 #include <asm/atomic.h>
 
@@ -60,6 +63,8 @@ static struct cgroup_subsys *subsys[] = {
 #include <linux/cgroup_subsys.h>
 };
 
+#define MAX_CGROUP_ROOT_NAMELEN 64
+
 /*
  * A cgroupfs_root represents the root of a cgroup hierarchy,
  * and may be associated with a superblock to form an active
@@ -74,6 +79,9 @@ struct cgroupfs_root {
 	 */
 	unsigned long subsys_bits;
 
+	/* Unique id for this hierarchy. */
+	int hierarchy_id;
+
 	/* The bitmask of subsystems currently attached to this hierarchy */
 	unsigned long actual_subsys_bits;
 
@@ -94,6 +102,9 @@ struct cgroupfs_root {
 
 	/* The path to use for release notifications. */
 	char release_agent_path[PATH_MAX];
+
+	/* The name for this hierarchy - may be empty */
+	char name[MAX_CGROUP_ROOT_NAMELEN];
 };
 
 /*
@@ -141,6 +152,10 @@ struct css_id {
 static LIST_HEAD(roots);
 static int root_count;
 
+static DEFINE_IDA(hierarchy_ida);
+static int next_hierarchy_id;
+static DEFINE_SPINLOCK(hierarchy_id_lock);
+
 /* dummytop is a shorthand for the dummy hierarchy's top cgroup */
 #define dummytop (&rootnode.top_cgroup)
 
@@ -201,6 +216,7 @@ struct cg_cgroup_link {
 	 * cgroup, anchored on cgroup->css_sets
 	 */
 	struct list_head cgrp_link_list;
+	struct cgroup *cgrp;
 	/*
 	 * List running through cg_cgroup_links pointing at a
 	 * single css_set object, anchored on css_set->cg_links
@@ -227,8 +243,11 @@ static int cgroup_subsys_init_idr(struct cgroup_subsys *ss);
 static DEFINE_RWLOCK(css_set_lock);
 static int css_set_count;
 
-/* hash table for cgroup groups. This improves the performance to
- * find an existing css_set */
+/*
+ * hash table for cgroup groups. This improves the performance to find
+ * an existing css_set. This hash doesn't (currently) take into
+ * account cgroups in empty hierarchies.
+ */
 #define CSS_SET_HASH_BITS	7
 #define CSS_SET_TABLE_SIZE	(1 << CSS_SET_HASH_BITS)
 static struct hlist_head css_set_table[CSS_SET_TABLE_SIZE];
@@ -248,48 +267,22 @@ static struct hlist_head *css_set_hash(struct cgroup_subsys_state *css[])
 	return &css_set_table[index];
 }
 
+static void free_css_set_rcu(struct rcu_head *obj)
+{
+	struct css_set *cg = container_of(obj, struct css_set, rcu_head);
+	kfree(cg);
+}
+
 /* We don't maintain the lists running through each css_set to its
  * task until after the first call to cgroup_iter_start(). This
  * reduces the fork()/exit() overhead for people who have cgroups
  * compiled into their kernel but not actually in use */
 static int use_task_css_set_links __read_mostly;
 
-/* When we create or destroy a css_set, the operation simply
- * takes/releases a reference count on all the cgroups referenced
- * by subsystems in this css_set. This can end up multiple-counting
- * some cgroups, but that's OK - the ref-count is just a
- * busy/not-busy indicator; ensuring that we only count each cgroup
- * once would require taking a global lock to ensure that no
- * subsystems moved between hierarchies while we were doing so.
- *
- * Possible TODO: decide at boot time based on the number of
- * registered subsystems and the number of CPUs or NUMA nodes whether
- * it's better for performance to ref-count every subsystem, or to
- * take a global lock and only add one ref count to each hierarchy.
- */
-
-/*
- * unlink a css_set from the list and free it
- */
-static void unlink_css_set(struct css_set *cg)
+static void __put_css_set(struct css_set *cg, int taskexit)
 {
 	struct cg_cgroup_link *link;
 	struct cg_cgroup_link *saved_link;
-
-	hlist_del(&cg->hlist);
-	css_set_count--;
-
-	list_for_each_entry_safe(link, saved_link, &cg->cg_links,
-				 cg_link_list) {
-		list_del(&link->cg_link_list);
-		list_del(&link->cgrp_link_list);
-		kfree(link);
-	}
-}
-
-static void __put_css_set(struct css_set *cg, int taskexit)
-{
-	int i;
 	/*
 	 * Ensure that the refcount doesn't hit zero while any readers
 	 * can see it. Similar to atomic_dec_and_lock(), but for an
@@ -302,21 +295,28 @@ static void __put_css_set(struct css_set *cg, int taskexit)
 		write_unlock(&css_set_lock);
 		return;
 	}
-	unlink_css_set(cg);
-	write_unlock(&css_set_lock);
 
-	rcu_read_lock();
-	for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
-		struct cgroup *cgrp = rcu_dereference(cg->subsys[i]->cgroup);
+	/* This css_set is dead. unlink it and release cgroup refcounts */
+	hlist_del(&cg->hlist);
+	css_set_count--;
+
+	list_for_each_entry_safe(link, saved_link, &cg->cg_links,
+				 cg_link_list) {
+		struct cgroup *cgrp = link->cgrp;
+		list_del(&link->cg_link_list);
+		list_del(&link->cgrp_link_list);
 		if (atomic_dec_and_test(&cgrp->count) &&
 		    notify_on_release(cgrp)) {
 			if (taskexit)
 				set_bit(CGRP_RELEASABLE, &cgrp->flags);
 			check_for_release(cgrp);
 		}
+
+		kfree(link);
 	}
-	rcu_read_unlock();
-	kfree(cg);
+
+	write_unlock(&css_set_lock);
+	call_rcu(&cg->rcu_head, free_css_set_rcu);
 }
 
 /*
@@ -338,6 +338,78 @@ static inline void put_css_set_taskexit(struct css_set *cg)
 }
 
 /*
+ * compare_css_sets - helper function for find_existing_css_set().
+ * @cg: candidate css_set being tested
+ * @old_cg: existing css_set for a task
+ * @new_cgrp: cgroup that's being entered by the task
+ * @template: desired set of css pointers in css_set (pre-calculated)
+ *
+ * Returns true if "cg" matches "old_cg" except for the hierarchy
+ * which "new_cgrp" belongs to, for which it should match "new_cgrp".
+ */
+static bool compare_css_sets(struct css_set *cg,
+			     struct css_set *old_cg,
+			     struct cgroup *new_cgrp,
+			     struct cgroup_subsys_state *template[])
+{
+	struct list_head *l1, *l2;
+
+	if (memcmp(template, cg->subsys, sizeof(cg->subsys))) {
+		/* Not all subsystems matched */
+		return false;
+	}
+
+	/*
+	 * Compare cgroup pointers in order to distinguish between
+	 * different cgroups in heirarchies with no subsystems. We
+	 * could get by with just this check alone (and skip the
+	 * memcmp above) but on most setups the memcmp check will
+	 * avoid the need for this more expensive check on almost all
+	 * candidates.
+	 */
+
+	l1 = &cg->cg_links;
+	l2 = &old_cg->cg_links;
+	while (1) {
+		struct cg_cgroup_link *cgl1, *cgl2;
+		struct cgroup *cg1, *cg2;
+
+		l1 = l1->next;
+		l2 = l2->next;
+		/* See if we reached the end - both lists are equal length. */
+		if (l1 == &cg->cg_links) {
+			BUG_ON(l2 != &old_cg->cg_links);
+			break;
+		} else {
+			BUG_ON(l2 == &old_cg->cg_links);
+		}
+		/* Locate the cgroups associated with these links. */
+		cgl1 = list_entry(l1, struct cg_cgroup_link, cg_link_list);
+		cgl2 = list_entry(l2, struct cg_cgroup_link, cg_link_list);
+		cg1 = cgl1->cgrp;
+		cg2 = cgl2->cgrp;
+		/* Hierarchies should be linked in the same order. */
+		BUG_ON(cg1->root != cg2->root);
+
+		/*
+		 * If this hierarchy is the hierarchy of the cgroup
+		 * that's changing, then we need to check that this
+		 * css_set points to the new cgroup; if it's any other
+		 * hierarchy, then this css_set should point to the
+		 * same cgroup as the old css_set.
+		 */
+		if (cg1->root == new_cgrp->root) {
+			if (cg1 != new_cgrp)
+				return false;
+		} else {
+			if (cg1 != cg2)
+				return false;
+		}
+	}
+	return true;
+}
+
+/*
  * find_existing_css_set() is a helper for
  * find_css_set(), and checks to see whether an existing
  * css_set is suitable.
@@ -378,10 +450,11 @@ static struct css_set *find_existing_css_set(
 
 	hhead = css_set_hash(template);
 	hlist_for_each_entry(cg, node, hhead, hlist) {
-		if (!memcmp(template, cg->subsys, sizeof(cg->subsys))) {
-			/* All subsystems matched */
-			return cg;
-		}
+		if (!compare_css_sets(cg, oldcg, cgrp, template))
+			continue;
+
+		/* This css_set matches what we need */
+		return cg;
 	}
 
 	/* No existing cgroup group matched */
@@ -435,8 +508,14 @@ static void link_css_set(struct list_head *tmp_cg_links,
 	link = list_first_entry(tmp_cg_links, struct cg_cgroup_link,
 				cgrp_link_list);
 	link->cg = cg;
+	link->cgrp = cgrp;
+	atomic_inc(&cgrp->count);
 	list_move(&link->cgrp_link_list, &cgrp->css_sets);
-	list_add(&link->cg_link_list, &cg->cg_links);
+	/*
+	 * Always add links to the tail of the list so that the list
+	 * is sorted by order of hierarchy creation
+	 */
+	list_add_tail(&link->cg_link_list, &cg->cg_links);
 }
 
 /*
@@ -451,11 +530,11 @@ static struct css_set *find_css_set(
 {
 	struct css_set *res;
 	struct cgroup_subsys_state *template[CGROUP_SUBSYS_COUNT];
-	int i;
 
 	struct list_head tmp_cg_links;
 
 	struct hlist_head *hhead;
+	struct cg_cgroup_link *link;
 
 	/* First see if we already have a cgroup group that matches
 	 * the desired set */
@@ -489,20 +568,12 @@ static struct css_set *find_css_set(
 
 	write_lock(&css_set_lock);
 	/* Add reference counts and links from the new css_set. */
-	for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
-		struct cgroup *cgrp = res->subsys[i]->cgroup;
-		struct cgroup_subsys *ss = subsys[i];
-		atomic_inc(&cgrp->count);
-		/*
-		 * We want to add a link once per cgroup, so we
-		 * only do it for the first subsystem in each
-		 * hierarchy
-		 */
-		if (ss->root->subsys_list.next == &ss->sibling)
-			link_css_set(&tmp_cg_links, res, cgrp);
+	list_for_each_entry(link, &oldcg->cg_links, cg_link_list) {
+		struct cgroup *c = link->cgrp;
+		if (c->root == cgrp->root)
+			c = cgrp;
+		link_css_set(&tmp_cg_links, res, c);
 	}
-	if (list_empty(&rootnode.subsys_list))
-		link_css_set(&tmp_cg_links, res, dummytop);
 
 	BUG_ON(!list_empty(&tmp_cg_links));
 
@@ -518,6 +589,41 @@ static struct css_set *find_css_set(
 }
 
 /*
+ * Return the cgroup for "task" from the given hierarchy. Must be
+ * called with cgroup_mutex held.
+ */
+static struct cgroup *task_cgroup_from_root(struct task_struct *task,
+					    struct cgroupfs_root *root)
+{
+	struct css_set *css;
+	struct cgroup *res = NULL;
+
+	BUG_ON(!mutex_is_locked(&cgroup_mutex));
+	read_lock(&css_set_lock);
+	/*
+	 * No need to lock the task - since we hold cgroup_mutex the
+	 * task can't change groups, so the only thing that can happen
+	 * is that it exits and its css is set back to init_css_set.
+	 */
+	css = task->cgroups;
+	if (css == &init_css_set) {
+		res = &root->top_cgroup;
+	} else {
+		struct cg_cgroup_link *link;
+		list_for_each_entry(link, &css->cg_links, cg_link_list) {
+			struct cgroup *c = link->cgrp;
+			if (c->root == root) {
+				res = c;
+				break;
+			}
+		}
+	}
+	read_unlock(&css_set_lock);
+	BUG_ON(!res);
+	return res;
+}
+
+/*
  * There is one global cgroup mutex. We also require taking
  * task_lock() when dereferencing a task's cgroup subsys pointers.
  * See "The task_lock() exception", at the end of this comment.
@@ -596,8 +702,8 @@ void cgroup_unlock(void)
 static int cgroup_mkdir(struct inode *dir, struct dentry *dentry, int mode);
 static int cgroup_rmdir(struct inode *unused_dir, struct dentry *dentry);
 static int cgroup_populate_dir(struct cgroup *cgrp);
-static struct inode_operations cgroup_dir_inode_operations;
-static struct file_operations proc_cgroupstats_operations;
+static const struct inode_operations cgroup_dir_inode_operations;
+static const struct file_operations proc_cgroupstats_operations;
 
 static struct backing_dev_info cgroup_backing_dev_info = {
 	.name		= "cgroup",
@@ -677,6 +783,12 @@ static void cgroup_diput(struct dentry *dentry, struct inode *inode)
 		 */
 		deactivate_super(cgrp->root->sb);
 
+		/*
+		 * if we're getting rid of the cgroup, refcount should ensure
+		 * that there are no pidlists left.
+		 */
+		BUG_ON(!list_empty(&cgrp->pidlists));
+
 		call_rcu(&cgrp->rcu_head, free_cgroup_rcu);
 	}
 	iput(inode);
@@ -841,6 +953,8 @@ static int cgroup_show_options(struct seq_file *seq, struct vfsmount *vfs)
 		seq_puts(seq, ",noprefix");
 	if (strlen(root->release_agent_path))
 		seq_printf(seq, ",release_agent=%s", root->release_agent_path);
+	if (strlen(root->name))
+		seq_printf(seq, ",name=%s", root->name);
 	mutex_unlock(&cgroup_mutex);
 	return 0;
 }
@@ -849,6 +963,12 @@ struct cgroup_sb_opts {
 	unsigned long subsys_bits;
 	unsigned long flags;
 	char *release_agent;
+	char *name;
+	/* User explicitly requested empty subsystem */
+	bool none;
+
+	struct cgroupfs_root *new_root;
+
 };
 
 /* Convert a hierarchy specifier into a bitmask of subsystems and
@@ -863,9 +983,7 @@ static int parse_cgroupfs_options(char *data,
 	mask = ~(1UL << cpuset_subsys_id);
 #endif
 
-	opts->subsys_bits = 0;
-	opts->flags = 0;
-	opts->release_agent = NULL;
+	memset(opts, 0, sizeof(*opts));
 
 	while ((token = strsep(&o, ",")) != NULL) {
 		if (!*token)
@@ -879,17 +997,42 @@ static int parse_cgroupfs_options(char *data,
 				if (!ss->disabled)
 					opts->subsys_bits |= 1ul << i;
 			}
+		} else if (!strcmp(token, "none")) {
+			/* Explicitly have no subsystems */
+			opts->none = true;
 		} else if (!strcmp(token, "noprefix")) {
 			set_bit(ROOT_NOPREFIX, &opts->flags);
 		} else if (!strncmp(token, "release_agent=", 14)) {
 			/* Specifying two release agents is forbidden */
 			if (opts->release_agent)
 				return -EINVAL;
-			opts->release_agent = kzalloc(PATH_MAX, GFP_KERNEL);
+			opts->release_agent =
+				kstrndup(token + 14, PATH_MAX, GFP_KERNEL);
 			if (!opts->release_agent)
 				return -ENOMEM;
-			strncpy(opts->release_agent, token + 14, PATH_MAX - 1);
-			opts->release_agent[PATH_MAX - 1] = 0;
+		} else if (!strncmp(token, "name=", 5)) {
+			int i;
+			const char *name = token + 5;
+			/* Can't specify an empty name */
+			if (!strlen(name))
+				return -EINVAL;
+			/* Must match [\w.-]+ */
+			for (i = 0; i < strlen(name); i++) {
+				char c = name[i];
+				if (isalnum(c))
+					continue;
+				if ((c == '.') || (c == '-') || (c == '_'))
+					continue;
+				return -EINVAL;
+			}
+			/* Specifying two names is forbidden */
+			if (opts->name)
+				return -EINVAL;
+			opts->name = kstrndup(name,
+					      MAX_CGROUP_ROOT_NAMELEN,
+					      GFP_KERNEL);
+			if (!opts->name)
+				return -ENOMEM;
 		} else {
 			struct cgroup_subsys *ss;
 			int i;
@@ -906,6 +1049,8 @@ static int parse_cgroupfs_options(char *data,
 		}
 	}
 
+	/* Consistency checks */
+
 	/*
 	 * Option noprefix was introduced just for backward compatibility
 	 * with the old cpuset, so we allow noprefix only if mounting just
@@ -915,8 +1060,16 @@ static int parse_cgroupfs_options(char *data,
 	    (opts->subsys_bits & mask))
 		return -EINVAL;
 
-	/* We can't have an empty hierarchy */
-	if (!opts->subsys_bits)
+
+	/* Can't specify "none" and some subsystems */
+	if (opts->subsys_bits && opts->none)
+		return -EINVAL;
+
+	/*
+	 * We either have to specify by name or by subsystems. (So all
+	 * empty hierarchies must have a name).
+	 */
+	if (!opts->subsys_bits && !opts->name)
 		return -EINVAL;
 
 	return 0;
@@ -944,6 +1097,12 @@ static int cgroup_remount(struct super_block *sb, int *flags, char *data)
 		goto out_unlock;
 	}
 
+	/* Don't allow name to change at remount */
+	if (opts.name && strcmp(opts.name, root->name)) {
+		ret = -EINVAL;
+		goto out_unlock;
+	}
+
 	ret = rebind_subsystems(root, opts.subsys_bits);
 	if (ret)
 		goto out_unlock;
@@ -955,13 +1114,14 @@ static int cgroup_remount(struct super_block *sb, int *flags, char *data)
 		strcpy(root->release_agent_path, opts.release_agent);
  out_unlock:
 	kfree(opts.release_agent);
+	kfree(opts.name);
 	mutex_unlock(&cgroup_mutex);
 	mutex_unlock(&cgrp->dentry->d_inode->i_mutex);
 	unlock_kernel();
 	return ret;
 }
 
-static struct super_operations cgroup_ops = {
+static const struct super_operations cgroup_ops = {
 	.statfs = simple_statfs,
 	.drop_inode = generic_delete_inode,
 	.show_options = cgroup_show_options,
@@ -974,9 +1134,10 @@ static void init_cgroup_housekeeping(struct cgroup *cgrp)
 	INIT_LIST_HEAD(&cgrp->children);
 	INIT_LIST_HEAD(&cgrp->css_sets);
 	INIT_LIST_HEAD(&cgrp->release_list);
-	INIT_LIST_HEAD(&cgrp->pids_list);
-	init_rwsem(&cgrp->pids_mutex);
+	INIT_LIST_HEAD(&cgrp->pidlists);
+	mutex_init(&cgrp->pidlist_mutex);
 }
+
 static void init_cgroup_root(struct cgroupfs_root *root)
 {
 	struct cgroup *cgrp = &root->top_cgroup;
@@ -988,33 +1149,106 @@ static void init_cgroup_root(struct cgroupfs_root *root)
 	init_cgroup_housekeeping(cgrp);
 }
 
+static bool init_root_id(struct cgroupfs_root *root)
+{
+	int ret = 0;
+
+	do {
+		if (!ida_pre_get(&hierarchy_ida, GFP_KERNEL))
+			return false;
+		spin_lock(&hierarchy_id_lock);
+		/* Try to allocate the next unused ID */
+		ret = ida_get_new_above(&hierarchy_ida, next_hierarchy_id,
+					&root->hierarchy_id);
+		if (ret == -ENOSPC)
+			/* Try again starting from 0 */
+			ret = ida_get_new(&hierarchy_ida, &root->hierarchy_id);
+		if (!ret) {
+			next_hierarchy_id = root->hierarchy_id + 1;
+		} else if (ret != -EAGAIN) {
+			/* Can only get here if the 31-bit IDR is full ... */
+			BUG_ON(ret);
+		}
+		spin_unlock(&hierarchy_id_lock);
+	} while (ret);
+	return true;
+}
+
 static int cgroup_test_super(struct super_block *sb, void *data)
 {
-	struct cgroupfs_root *new = data;
+	struct cgroup_sb_opts *opts = data;
 	struct cgroupfs_root *root = sb->s_fs_info;
 
-	/* First check subsystems */
-	if (new->subsys_bits != root->subsys_bits)
-	    return 0;
+	/* If we asked for a name then it must match */
+	if (opts->name && strcmp(opts->name, root->name))
+		return 0;
 
-	/* Next check flags */
-	if (new->flags != root->flags)
+	/*
+	 * If we asked for subsystems (or explicitly for no
+	 * subsystems) then they must match
+	 */
+	if ((opts->subsys_bits || opts->none)
+	    && (opts->subsys_bits != root->subsys_bits))
 		return 0;
 
 	return 1;
 }
 
+static struct cgroupfs_root *cgroup_root_from_opts(struct cgroup_sb_opts *opts)
+{
+	struct cgroupfs_root *root;
+
+	if (!opts->subsys_bits && !opts->none)
+		return NULL;
+
+	root = kzalloc(sizeof(*root), GFP_KERNEL);
+	if (!root)
+		return ERR_PTR(-ENOMEM);
+
+	if (!init_root_id(root)) {
+		kfree(root);
+		return ERR_PTR(-ENOMEM);
+	}
+	init_cgroup_root(root);
+
+	root->subsys_bits = opts->subsys_bits;
+	root->flags = opts->flags;
+	if (opts->release_agent)
+		strcpy(root->release_agent_path, opts->release_agent);
+	if (opts->name)
+		strcpy(root->name, opts->name);
+	return root;
+}
+
+static void cgroup_drop_root(struct cgroupfs_root *root)
+{
+	if (!root)
+		return;
+
+	BUG_ON(!root->hierarchy_id);
+	spin_lock(&hierarchy_id_lock);
+	ida_remove(&hierarchy_ida, root->hierarchy_id);
+	spin_unlock(&hierarchy_id_lock);
+	kfree(root);
+}
+
 static int cgroup_set_super(struct super_block *sb, void *data)
 {
 	int ret;
-	struct cgroupfs_root *root = data;
+	struct cgroup_sb_opts *opts = data;
+
+	/* If we don't have a new root, we can't set up a new sb */
+	if (!opts->new_root)
+		return -EINVAL;
+
+	BUG_ON(!opts->subsys_bits && !opts->none);
 
 	ret = set_anon_super(sb, NULL);
 	if (ret)
 		return ret;
 
-	sb->s_fs_info = root;
-	root->sb = sb;
+	sb->s_fs_info = opts->new_root;
+	opts->new_root->sb = sb;
 
 	sb->s_blocksize = PAGE_CACHE_SIZE;
 	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
@@ -1051,48 +1285,43 @@ static int cgroup_get_sb(struct file_system_type *fs_type,
 			 void *data, struct vfsmount *mnt)
 {
 	struct cgroup_sb_opts opts;
+	struct cgroupfs_root *root;
 	int ret = 0;
 	struct super_block *sb;
-	struct cgroupfs_root *root;
-	struct list_head tmp_cg_links;
+	struct cgroupfs_root *new_root;
 
 	/* First find the desired set of subsystems */
 	ret = parse_cgroupfs_options(data, &opts);
-	if (ret) {
-		kfree(opts.release_agent);
-		return ret;
-	}
-
-	root = kzalloc(sizeof(*root), GFP_KERNEL);
-	if (!root) {
-		kfree(opts.release_agent);
-		return -ENOMEM;
-	}
+	if (ret)
+		goto out_err;
 
-	init_cgroup_root(root);
-	root->subsys_bits = opts.subsys_bits;
-	root->flags = opts.flags;
-	if (opts.release_agent) {
-		strcpy(root->release_agent_path, opts.release_agent);
-		kfree(opts.release_agent);
+	/*
+	 * Allocate a new cgroup root. We may not need it if we're
+	 * reusing an existing hierarchy.
+	 */
+	new_root = cgroup_root_from_opts(&opts);
+	if (IS_ERR(new_root)) {
+		ret = PTR_ERR(new_root);
+		goto out_err;
 	}
+	opts.new_root = new_root;
 
-	sb = sget(fs_type, cgroup_test_super, cgroup_set_super, root);
-
+	/* Locate an existing or new sb for this hierarchy */
+	sb = sget(fs_type, cgroup_test_super, cgroup_set_super, &opts);
 	if (IS_ERR(sb)) {
-		kfree(root);
-		return PTR_ERR(sb);
+		ret = PTR_ERR(sb);
+		cgroup_drop_root(opts.new_root);
+		goto out_err;
 	}
 
-	if (sb->s_fs_info != root) {
-		/* Reusing an existing superblock */
-		BUG_ON(sb->s_root == NULL);
-		kfree(root);
-		root = NULL;
-	} else {
-		/* New superblock */
+	root = sb->s_fs_info;
+	BUG_ON(!root);
+	if (root == opts.new_root) {
+		/* We used the new root structure, so this is a new hierarchy */
+		struct list_head tmp_cg_links;
 		struct cgroup *root_cgrp = &root->top_cgroup;
 		struct inode *inode;
+		struct cgroupfs_root *existing_root;
 		int i;
 
 		BUG_ON(sb->s_root != NULL);
@@ -1105,6 +1334,18 @@ static int cgroup_get_sb(struct file_system_type *fs_type,
 		mutex_lock(&inode->i_mutex);
 		mutex_lock(&cgroup_mutex);
 
+		if (strlen(root->name)) {
+			/* Check for name clashes with existing mounts */
+			for_each_active_root(existing_root) {
+				if (!strcmp(existing_root->name, root->name)) {
+					ret = -EBUSY;
+					mutex_unlock(&cgroup_mutex);
+					mutex_unlock(&inode->i_mutex);
+					goto drop_new_super;
+				}
+			}
+		}
+
 		/*
 		 * We're accessing css_set_count without locking
 		 * css_set_lock here, but that's OK - it can only be
@@ -1123,7 +1364,8 @@ static int cgroup_get_sb(struct file_system_type *fs_type,
 		if (ret == -EBUSY) {
 			mutex_unlock(&cgroup_mutex);
 			mutex_unlock(&inode->i_mutex);
-			goto free_cg_links;
+			free_cg_links(&tmp_cg_links);
+			goto drop_new_super;
 		}
 
 		/* EBUSY should be the only error here */
@@ -1155,17 +1397,27 @@ static int cgroup_get_sb(struct file_system_type *fs_type,
 		BUG_ON(root->number_of_cgroups != 1);
 
 		cgroup_populate_dir(root_cgrp);
-		mutex_unlock(&inode->i_mutex);
 		mutex_unlock(&cgroup_mutex);
+		mutex_unlock(&inode->i_mutex);
+	} else {
+		/*
+		 * We re-used an existing hierarchy - the new root (if
+		 * any) is not needed
+		 */
+		cgroup_drop_root(opts.new_root);
 	}
 
 	simple_set_mnt(mnt, sb);
+	kfree(opts.release_agent);
+	kfree(opts.name);
 	return 0;
 
- free_cg_links:
-	free_cg_links(&tmp_cg_links);
  drop_new_super:
 	deactivate_locked_super(sb);
+ out_err:
+	kfree(opts.release_agent);
+	kfree(opts.name);
+
 	return ret;
 }
 
@@ -1211,7 +1463,7 @@ static void cgroup_kill_sb(struct super_block *sb) {
 	mutex_unlock(&cgroup_mutex);
 
 	kill_litter_super(sb);
-	kfree(root);
+	cgroup_drop_root(root);
 }
 
 static struct file_system_type cgroup_fs_type = {
@@ -1276,27 +1528,6 @@ int cgroup_path(const struct cgroup *cgrp, char *buf, int buflen)
 	return 0;
 }
 
-/*
- * Return the first subsystem attached to a cgroup's hierarchy, and
- * its subsystem id.
- */
-
-static void get_first_subsys(const struct cgroup *cgrp,
-			struct cgroup_subsys_state **css, int *subsys_id)
-{
-	const struct cgroupfs_root *root = cgrp->root;
-	const struct cgroup_subsys *test_ss;
-	BUG_ON(list_empty(&root->subsys_list));
-	test_ss = list_entry(root->subsys_list.next,
-			     struct cgroup_subsys, sibling);
-	if (css) {
-		*css = cgrp->subsys[test_ss->subsys_id];
-		BUG_ON(!*css);
-	}
-	if (subsys_id)
-		*subsys_id = test_ss->subsys_id;
-}
-
 /**
  * cgroup_attach_task - attach task 'tsk' to cgroup 'cgrp'
  * @cgrp: the cgroup the task is attaching to
@@ -1313,18 +1544,15 @@ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk)
 	struct css_set *cg;
 	struct css_set *newcg;
 	struct cgroupfs_root *root = cgrp->root;
-	int subsys_id;
-
-	get_first_subsys(cgrp, NULL, &subsys_id);
 
 	/* Nothing to do if the task is already in that cgroup */
-	oldcgrp = task_cgroup(tsk, subsys_id);
+	oldcgrp = task_cgroup_from_root(tsk, root);
 	if (cgrp == oldcgrp)
 		return 0;
 
 	for_each_subsys(root, ss) {
 		if (ss->can_attach) {
-			retval = ss->can_attach(ss, cgrp, tsk);
+			retval = ss->can_attach(ss, cgrp, tsk, false);
 			if (retval)
 				return retval;
 		}
@@ -1362,7 +1590,7 @@ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk)
 
 	for_each_subsys(root, ss) {
 		if (ss->attach)
-			ss->attach(ss, cgrp, oldcgrp, tsk);
+			ss->attach(ss, cgrp, oldcgrp, tsk, false);
 	}
 	set_bit(CGRP_RELEASABLE, &oldcgrp->flags);
 	synchronize_rcu();
@@ -1423,15 +1651,6 @@ static int cgroup_tasks_write(struct cgroup *cgrp, struct cftype *cft, u64 pid)
 	return ret;
 }
 
-/* The various types of files and directories in a cgroup file system */
-enum cgroup_filetype {
-	FILE_ROOT,
-	FILE_DIR,
-	FILE_TASKLIST,
-	FILE_NOTIFY_ON_RELEASE,
-	FILE_RELEASE_AGENT,
-};
-
 /**
  * cgroup_lock_live_group - take cgroup_mutex and check that cgrp is alive.
  * @cgrp: the cgroup to be checked for liveness
@@ -1644,7 +1863,7 @@ static int cgroup_seqfile_release(struct inode *inode, struct file *file)
 	return single_release(inode, file);
 }
 
-static struct file_operations cgroup_seqfile_operations = {
+static const struct file_operations cgroup_seqfile_operations = {
 	.read = seq_read,
 	.write = cgroup_file_write,
 	.llseek = seq_lseek,
@@ -1703,7 +1922,7 @@ static int cgroup_rename(struct inode *old_dir, struct dentry *old_dentry,
 	return simple_rename(old_dir, old_dentry, new_dir, new_dentry);
 }
 
-static struct file_operations cgroup_file_operations = {
+static const struct file_operations cgroup_file_operations = {
 	.read = cgroup_file_read,
 	.write = cgroup_file_write,
 	.llseek = generic_file_llseek,
@@ -1711,7 +1930,7 @@ static struct file_operations cgroup_file_operations = {
 	.release = cgroup_file_release,
 };
 
-static struct inode_operations cgroup_dir_inode_operations = {
+static const struct inode_operations cgroup_dir_inode_operations = {
 	.lookup = simple_lookup,
 	.mkdir = cgroup_mkdir,
 	.rmdir = cgroup_rmdir,
@@ -1876,7 +2095,7 @@ int cgroup_task_count(const struct cgroup *cgrp)
  * the start of a css_set
  */
 static void cgroup_advance_iter(struct cgroup *cgrp,
-					  struct cgroup_iter *it)
+				struct cgroup_iter *it)
 {
 	struct list_head *l = it->cg_link;
 	struct cg_cgroup_link *link;
@@ -2129,7 +2348,7 @@ int cgroup_scan_tasks(struct cgroup_scanner *scan)
 }
 
 /*
- * Stuff for reading the 'tasks' file.
+ * Stuff for reading the 'tasks'/'procs' files.
  *
  * Reading this file can return large amounts of data if a cgroup has
  * *lots* of attached tasks. So it may need several calls to read(),
@@ -2139,27 +2358,196 @@ int cgroup_scan_tasks(struct cgroup_scanner *scan)
  */
 
 /*
- * Load into 'pidarray' up to 'npids' of the tasks using cgroup
- * 'cgrp'.  Return actual number of pids loaded.  No need to
- * task_lock(p) when reading out p->cgroup, since we're in an RCU
- * read section, so the css_set can't go away, and is
- * immutable after creation.
+ * The following two functions "fix" the issue where there are more pids
+ * than kmalloc will give memory for; in such cases, we use vmalloc/vfree.
+ * TODO: replace with a kernel-wide solution to this problem
+ */
+#define PIDLIST_TOO_LARGE(c) ((c) * sizeof(pid_t) > (PAGE_SIZE * 2))
+static void *pidlist_allocate(int count)
+{
+	if (PIDLIST_TOO_LARGE(count))
+		return vmalloc(count * sizeof(pid_t));
+	else
+		return kmalloc(count * sizeof(pid_t), GFP_KERNEL);
+}
+static void pidlist_free(void *p)
+{
+	if (is_vmalloc_addr(p))
+		vfree(p);
+	else
+		kfree(p);
+}
+static void *pidlist_resize(void *p, int newcount)
+{
+	void *newlist;
+	/* note: if new alloc fails, old p will still be valid either way */
+	if (is_vmalloc_addr(p)) {
+		newlist = vmalloc(newcount * sizeof(pid_t));
+		if (!newlist)
+			return NULL;
+		memcpy(newlist, p, newcount * sizeof(pid_t));
+		vfree(p);
+	} else {
+		newlist = krealloc(p, newcount * sizeof(pid_t), GFP_KERNEL);
+	}
+	return newlist;
+}
+
+/*
+ * pidlist_uniq - given a kmalloc()ed list, strip out all duplicate entries
+ * If the new stripped list is sufficiently smaller and there's enough memory
+ * to allocate a new buffer, will let go of the unneeded memory. Returns the
+ * number of unique elements.
+ */
+/* is the size difference enough that we should re-allocate the array? */
+#define PIDLIST_REALLOC_DIFFERENCE(old, new) ((old) - PAGE_SIZE >= (new))
+static int pidlist_uniq(pid_t **p, int length)
+{
+	int src, dest = 1;
+	pid_t *list = *p;
+	pid_t *newlist;
+
+	/*
+	 * we presume the 0th element is unique, so i starts at 1. trivial
+	 * edge cases first; no work needs to be done for either
+	 */
+	if (length == 0 || length == 1)
+		return length;
+	/* src and dest walk down the list; dest counts unique elements */
+	for (src = 1; src < length; src++) {
+		/* find next unique element */
+		while (list[src] == list[src-1]) {
+			src++;
+			if (src == length)
+				goto after;
+		}
+		/* dest always points to where the next unique element goes */
+		list[dest] = list[src];
+		dest++;
+	}
+after:
+	/*
+	 * if the length difference is large enough, we want to allocate a
+	 * smaller buffer to save memory. if this fails due to out of memory,
+	 * we'll just stay with what we've got.
+	 */
+	if (PIDLIST_REALLOC_DIFFERENCE(length, dest)) {
+		newlist = pidlist_resize(list, dest);
+		if (newlist)
+			*p = newlist;
+	}
+	return dest;
+}
+
+static int cmppid(const void *a, const void *b)
+{
+	return *(pid_t *)a - *(pid_t *)b;
+}
+
+/*
+ * find the appropriate pidlist for our purpose (given procs vs tasks)
+ * returns with the lock on that pidlist already held, and takes care
+ * of the use count, or returns NULL with no locks held if we're out of
+ * memory.
  */
-static int pid_array_load(pid_t *pidarray, int npids, struct cgroup *cgrp)
+static struct cgroup_pidlist *cgroup_pidlist_find(struct cgroup *cgrp,
+						  enum cgroup_filetype type)
 {
-	int n = 0, pid;
+	struct cgroup_pidlist *l;
+	/* don't need task_nsproxy() if we're looking at ourself */
+	struct pid_namespace *ns = get_pid_ns(current->nsproxy->pid_ns);
+	/*
+	 * We can't drop the pidlist_mutex before taking the l->mutex in case
+	 * the last ref-holder is trying to remove l from the list at the same
+	 * time. Holding the pidlist_mutex precludes somebody taking whichever
+	 * list we find out from under us - compare release_pid_array().
+	 */
+	mutex_lock(&cgrp->pidlist_mutex);
+	list_for_each_entry(l, &cgrp->pidlists, links) {
+		if (l->key.type == type && l->key.ns == ns) {
+			/* found a matching list - drop the extra refcount */
+			put_pid_ns(ns);
+			/* make sure l doesn't vanish out from under us */
+			down_write(&l->mutex);
+			mutex_unlock(&cgrp->pidlist_mutex);
+			l->use_count++;
+			return l;
+		}
+	}
+	/* entry not found; create a new one */
+	l = kmalloc(sizeof(struct cgroup_pidlist), GFP_KERNEL);
+	if (!l) {
+		mutex_unlock(&cgrp->pidlist_mutex);
+		put_pid_ns(ns);
+		return l;
+	}
+	init_rwsem(&l->mutex);
+	down_write(&l->mutex);
+	l->key.type = type;
+	l->key.ns = ns;
+	l->use_count = 0; /* don't increment here */
+	l->list = NULL;
+	l->owner = cgrp;
+	list_add(&l->links, &cgrp->pidlists);
+	mutex_unlock(&cgrp->pidlist_mutex);
+	return l;
+}
+
+/*
+ * Load a cgroup's pidarray with either procs' tgids or tasks' pids
+ */
+static int pidlist_array_load(struct cgroup *cgrp, enum cgroup_filetype type,
+			      struct cgroup_pidlist **lp)
+{
+	pid_t *array;
+	int length;
+	int pid, n = 0; /* used for populating the array */
 	struct cgroup_iter it;
 	struct task_struct *tsk;
+	struct cgroup_pidlist *l;
+
+	/*
+	 * If cgroup gets more users after we read count, we won't have
+	 * enough space - tough.  This race is indistinguishable to the
+	 * caller from the case that the additional cgroup users didn't
+	 * show up until sometime later on.
+	 */
+	length = cgroup_task_count(cgrp);
+	array = pidlist_allocate(length);
+	if (!array)
+		return -ENOMEM;
+	/* now, populate the array */
 	cgroup_iter_start(cgrp, &it);
 	while ((tsk = cgroup_iter_next(cgrp, &it))) {
-		if (unlikely(n == npids))
+		if (unlikely(n == length))
 			break;
-		pid = task_pid_vnr(tsk);
-		if (pid > 0)
-			pidarray[n++] = pid;
+		/* get tgid or pid for procs or tasks file respectively */
+		if (type == CGROUP_FILE_PROCS)
+			pid = task_tgid_vnr(tsk);
+		else
+			pid = task_pid_vnr(tsk);
+		if (pid > 0) /* make sure to only use valid results */
+			array[n++] = pid;
 	}
 	cgroup_iter_end(cgrp, &it);
-	return n;
+	length = n;
+	/* now sort & (if procs) strip out duplicates */
+	sort(array, length, sizeof(pid_t), cmppid, NULL);
+	if (type == CGROUP_FILE_PROCS)
+		length = pidlist_uniq(&array, length);
+	l = cgroup_pidlist_find(cgrp, type);
+	if (!l) {
+		pidlist_free(array);
+		return -ENOMEM;
+	}
+	/* store array, freeing old if necessary - lock already held */
+	pidlist_free(l->list);
+	l->list = array;
+	l->length = length;
+	l->use_count++;
+	up_write(&l->mutex);
+	*lp = l;
+	return 0;
 }
 
 /**
@@ -2216,37 +2604,14 @@ err:
 	return ret;
 }
 
-/*
- * Cache pids for all threads in the same pid namespace that are
- * opening the same "tasks" file.
- */
-struct cgroup_pids {
-	/* The node in cgrp->pids_list */
-	struct list_head list;
-	/* The cgroup those pids belong to */
-	struct cgroup *cgrp;
-	/* The namepsace those pids belong to */
-	struct pid_namespace *ns;
-	/* Array of process ids in the cgroup */
-	pid_t *tasks_pids;
-	/* How many files are using the this tasks_pids array */
-	int use_count;
-	/* Length of the current tasks_pids array */
-	int length;
-};
-
-static int cmppid(const void *a, const void *b)
-{
-	return *(pid_t *)a - *(pid_t *)b;
-}
 
 /*
- * seq_file methods for the "tasks" file. The seq_file position is the
+ * seq_file methods for the tasks/procs files. The seq_file position is the
  * next pid to display; the seq_file iterator is a pointer to the pid
- * in the cgroup->tasks_pids array.
+ * in the cgroup->l->list array.
  */
 
-static void *cgroup_tasks_start(struct seq_file *s, loff_t *pos)
+static void *cgroup_pidlist_start(struct seq_file *s, loff_t *pos)
 {
 	/*
 	 * Initially we receive a position value that corresponds to
@@ -2254,48 +2619,45 @@ static void *cgroup_tasks_start(struct seq_file *s, loff_t *pos)
 	 * after a seek to the start). Use a binary-search to find the
 	 * next pid to display, if any
 	 */
-	struct cgroup_pids *cp = s->private;
-	struct cgroup *cgrp = cp->cgrp;
+	struct cgroup_pidlist *l = s->private;
 	int index = 0, pid = *pos;
 	int *iter;
 
-	down_read(&cgrp->pids_mutex);
+	down_read(&l->mutex);
 	if (pid) {
-		int end = cp->length;
+		int end = l->length;
 
 		while (index < end) {
 			int mid = (index + end) / 2;
-			if (cp->tasks_pids[mid] == pid) {
+			if (l->list[mid] == pid) {
 				index = mid;
 				break;
-			} else if (cp->tasks_pids[mid] <= pid)
+			} else if (l->list[mid] <= pid)
 				index = mid + 1;
 			else
 				end = mid;
 		}
 	}
 	/* If we're off the end of the array, we're done */
-	if (index >= cp->length)
+	if (index >= l->length)
 		return NULL;
 	/* Update the abstract position to be the actual pid that we found */
-	iter = cp->tasks_pids + index;
+	iter = l->list + index;
 	*pos = *iter;
 	return iter;
 }
 
-static void cgroup_tasks_stop(struct seq_file *s, void *v)
+static void cgroup_pidlist_stop(struct seq_file *s, void *v)
 {
-	struct cgroup_pids *cp = s->private;
-	struct cgroup *cgrp = cp->cgrp;
-	up_read(&cgrp->pids_mutex);
+	struct cgroup_pidlist *l = s->private;
+	up_read(&l->mutex);
 }
 
-static void *cgroup_tasks_next(struct seq_file *s, void *v, loff_t *pos)
+static void *cgroup_pidlist_next(struct seq_file *s, void *v, loff_t *pos)
 {
-	struct cgroup_pids *cp = s->private;
-	int *p = v;
-	int *end = cp->tasks_pids + cp->length;
-
+	struct cgroup_pidlist *l = s->private;
+	pid_t *p = v;
+	pid_t *end = l->list + l->length;
 	/*
 	 * Advance to the next pid in the array. If this goes off the
 	 * end, we're done
@@ -2309,124 +2671,107 @@ static void *cgroup_tasks_next(struct seq_file *s, void *v, loff_t *pos)
 	}
 }
 
-static int cgroup_tasks_show(struct seq_file *s, void *v)
+static int cgroup_pidlist_show(struct seq_file *s, void *v)
 {
 	return seq_printf(s, "%d\n", *(int *)v);
 }
 
-static struct seq_operations cgroup_tasks_seq_operations = {
-	.start = cgroup_tasks_start,
-	.stop = cgroup_tasks_stop,
-	.next = cgroup_tasks_next,
-	.show = cgroup_tasks_show,
+/*
+ * seq_operations functions for iterating on pidlists through seq_file -
+ * independent of whether it's tasks or procs
+ */
+static const struct seq_operations cgroup_pidlist_seq_operations = {
+	.start = cgroup_pidlist_start,
+	.stop = cgroup_pidlist_stop,
+	.next = cgroup_pidlist_next,
+	.show = cgroup_pidlist_show,
 };
 
-static void release_cgroup_pid_array(struct cgroup_pids *cp)
+static void cgroup_release_pid_array(struct cgroup_pidlist *l)
 {
-	struct cgroup *cgrp = cp->cgrp;
-
-	down_write(&cgrp->pids_mutex);
-	BUG_ON(!cp->use_count);
-	if (!--cp->use_count) {
-		list_del(&cp->list);
-		put_pid_ns(cp->ns);
-		kfree(cp->tasks_pids);
-		kfree(cp);
+	/*
+	 * the case where we're the last user of this particular pidlist will
+	 * have us remove it from the cgroup's list, which entails taking the
+	 * mutex. since in pidlist_find the pidlist->lock depends on cgroup->
+	 * pidlist_mutex, we have to take pidlist_mutex first.
+	 */
+	mutex_lock(&l->owner->pidlist_mutex);
+	down_write(&l->mutex);
+	BUG_ON(!l->use_count);
+	if (!--l->use_count) {
+		/* we're the last user if refcount is 0; remove and free */
+		list_del(&l->links);
+		mutex_unlock(&l->owner->pidlist_mutex);
+		pidlist_free(l->list);
+		put_pid_ns(l->key.ns);
+		up_write(&l->mutex);
+		kfree(l);
+		return;
 	}
-	up_write(&cgrp->pids_mutex);
+	mutex_unlock(&l->owner->pidlist_mutex);
+	up_write(&l->mutex);
 }
 
-static int cgroup_tasks_release(struct inode *inode, struct file *file)
+static int cgroup_pidlist_release(struct inode *inode, struct file *file)
 {
-	struct seq_file *seq;
-	struct cgroup_pids *cp;
-
+	struct cgroup_pidlist *l;
 	if (!(file->f_mode & FMODE_READ))
 		return 0;
-
-	seq = file->private_data;
-	cp = seq->private;
-
-	release_cgroup_pid_array(cp);
+	/*
+	 * the seq_file will only be initialized if the file was opened for
+	 * reading; hence we check if it's not null only in that case.
+	 */
+	l = ((struct seq_file *)file->private_data)->private;
+	cgroup_release_pid_array(l);
 	return seq_release(inode, file);
 }
 
-static struct file_operations cgroup_tasks_operations = {
+static const struct file_operations cgroup_pidlist_operations = {
 	.read = seq_read,
 	.llseek = seq_lseek,
 	.write = cgroup_file_write,
-	.release = cgroup_tasks_release,
+	.release = cgroup_pidlist_release,
 };
 
 /*
- * Handle an open on 'tasks' file.  Prepare an array containing the
- * process id's of tasks currently attached to the cgroup being opened.
+ * The following functions handle opens on a file that displays a pidlist
+ * (tasks or procs). Prepare an array of the process/thread IDs of whoever's
+ * in the cgroup.
  */
-
-static int cgroup_tasks_open(struct inode *unused, struct file *file)
+/* helper function for the two below it */
+static int cgroup_pidlist_open(struct file *file, enum cgroup_filetype type)
 {
 	struct cgroup *cgrp = __d_cgrp(file->f_dentry->d_parent);
-	struct pid_namespace *ns = current->nsproxy->pid_ns;
-	struct cgroup_pids *cp;
-	pid_t *pidarray;
-	int npids;
+	struct cgroup_pidlist *l;
 	int retval;
 
 	/* Nothing to do for write-only files */
 	if (!(file->f_mode & FMODE_READ))
 		return 0;
 
-	/*
-	 * If cgroup gets more users after we read count, we won't have
-	 * enough space - tough.  This race is indistinguishable to the
-	 * caller from the case that the additional cgroup users didn't
-	 * show up until sometime later on.
-	 */
-	npids = cgroup_task_count(cgrp);
-	pidarray = kmalloc(npids * sizeof(pid_t), GFP_KERNEL);
-	if (!pidarray)
-		return -ENOMEM;
-	npids = pid_array_load(pidarray, npids, cgrp);
-	sort(pidarray, npids, sizeof(pid_t), cmppid, NULL);
-
-	/*
-	 * Store the array in the cgroup, freeing the old
-	 * array if necessary
-	 */
-	down_write(&cgrp->pids_mutex);
-
-	list_for_each_entry(cp, &cgrp->pids_list, list) {
-		if (ns == cp->ns)
-			goto found;
-	}
-
-	cp = kzalloc(sizeof(*cp), GFP_KERNEL);
-	if (!cp) {
-		up_write(&cgrp->pids_mutex);
-		kfree(pidarray);
-		return -ENOMEM;
-	}
-	cp->cgrp = cgrp;
-	cp->ns = ns;
-	get_pid_ns(ns);
-	list_add(&cp->list, &cgrp->pids_list);
-found:
-	kfree(cp->tasks_pids);
-	cp->tasks_pids = pidarray;
-	cp->length = npids;
-	cp->use_count++;
-	up_write(&cgrp->pids_mutex);
-
-	file->f_op = &cgroup_tasks_operations;
+	/* have the array populated */
+	retval = pidlist_array_load(cgrp, type, &l);
+	if (retval)
+		return retval;
+	/* configure file information */
+	file->f_op = &cgroup_pidlist_operations;
 
-	retval = seq_open(file, &cgroup_tasks_seq_operations);
+	retval = seq_open(file, &cgroup_pidlist_seq_operations);
 	if (retval) {
-		release_cgroup_pid_array(cp);
+		cgroup_release_pid_array(l);
 		return retval;
 	}
-	((struct seq_file *)file->private_data)->private = cp;
+	((struct seq_file *)file->private_data)->private = l;
 	return 0;
 }
+static int cgroup_tasks_open(struct inode *unused, struct file *file)
+{
+	return cgroup_pidlist_open(file, CGROUP_FILE_TASKS);
+}
+static int cgroup_procs_open(struct inode *unused, struct file *file)
+{
+	return cgroup_pidlist_open(file, CGROUP_FILE_PROCS);
+}
 
 static u64 cgroup_read_notify_on_release(struct cgroup *cgrp,
 					    struct cftype *cft)
@@ -2449,21 +2794,27 @@ static int cgroup_write_notify_on_release(struct cgroup *cgrp,
 /*
  * for the common functions, 'private' gives the type of file
  */
+/* for hysterical raisins, we can't put this on the older files */
+#define CGROUP_FILE_GENERIC_PREFIX "cgroup."
 static struct cftype files[] = {
 	{
 		.name = "tasks",
 		.open = cgroup_tasks_open,
 		.write_u64 = cgroup_tasks_write,
-		.release = cgroup_tasks_release,
-		.private = FILE_TASKLIST,
+		.release = cgroup_pidlist_release,
 		.mode = S_IRUGO | S_IWUSR,
 	},
-
+	{
+		.name = CGROUP_FILE_GENERIC_PREFIX "procs",
+		.open = cgroup_procs_open,
+		/* .write_u64 = cgroup_procs_write, TODO */
+		.release = cgroup_pidlist_release,
+		.mode = S_IRUGO,
+	},
 	{
 		.name = "notify_on_release",
 		.read_u64 = cgroup_read_notify_on_release,
 		.write_u64 = cgroup_write_notify_on_release,
-		.private = FILE_NOTIFY_ON_RELEASE,
 	},
 };
 
@@ -2472,7 +2823,6 @@ static struct cftype cft_release_agent = {
 	.read_seq_string = cgroup_release_agent_show,
 	.write_string = cgroup_release_agent_write,
 	.max_write_len = PATH_MAX,
-	.private = FILE_RELEASE_AGENT,
 };
 
 static int cgroup_populate_dir(struct cgroup *cgrp)
@@ -2879,6 +3229,7 @@ int __init cgroup_init_early(void)
 	init_task.cgroups = &init_css_set;
 
 	init_css_set_link.cg = &init_css_set;
+	init_css_set_link.cgrp = dummytop;
 	list_add(&init_css_set_link.cgrp_link_list,
 		 &rootnode.top_cgroup.css_sets);
 	list_add(&init_css_set_link.cg_link_list,
@@ -2933,7 +3284,7 @@ int __init cgroup_init(void)
 	/* Add init_css_set to the hash table */
 	hhead = css_set_hash(init_css_set.subsys);
 	hlist_add_head(&init_css_set.hlist, hhead);
-
+	BUG_ON(!init_root_id(&rootnode));
 	err = register_filesystem(&cgroup_fs_type);
 	if (err < 0)
 		goto out;
@@ -2986,15 +3337,16 @@ static int proc_cgroup_show(struct seq_file *m, void *v)
 	for_each_active_root(root) {
 		struct cgroup_subsys *ss;
 		struct cgroup *cgrp;
-		int subsys_id;
 		int count = 0;
 
-		seq_printf(m, "%lu:", root->subsys_bits);
+		seq_printf(m, "%d:", root->hierarchy_id);
 		for_each_subsys(root, ss)
 			seq_printf(m, "%s%s", count++ ? "," : "", ss->name);
+		if (strlen(root->name))
+			seq_printf(m, "%sname=%s", count ? "," : "",
+				   root->name);
 		seq_putc(m, ':');
-		get_first_subsys(&root->top_cgroup, NULL, &subsys_id);
-		cgrp = task_cgroup(tsk, subsys_id);
+		cgrp = task_cgroup_from_root(tsk, root);
 		retval = cgroup_path(cgrp, buf, PAGE_SIZE);
 		if (retval < 0)
 			goto out_unlock;
@@ -3017,7 +3369,7 @@ static int cgroup_open(struct inode *inode, struct file *file)
 	return single_open(file, proc_cgroup_show, pid);
 }
 
-struct file_operations proc_cgroup_operations = {
+const struct file_operations proc_cgroup_operations = {
 	.open		= cgroup_open,
 	.read		= seq_read,
 	.llseek		= seq_lseek,
@@ -3033,8 +3385,8 @@ static int proc_cgroupstats_show(struct seq_file *m, void *v)
 	mutex_lock(&cgroup_mutex);
 	for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
 		struct cgroup_subsys *ss = subsys[i];
-		seq_printf(m, "%s\t%lu\t%d\t%d\n",
-			   ss->name, ss->root->subsys_bits,
+		seq_printf(m, "%s\t%d\t%d\t%d\n",
+			   ss->name, ss->root->hierarchy_id,
 			   ss->root->number_of_cgroups, !ss->disabled);
 	}
 	mutex_unlock(&cgroup_mutex);
@@ -3046,7 +3398,7 @@ static int cgroupstats_open(struct inode *inode, struct file *file)
 	return single_open(file, proc_cgroupstats_show, NULL);
 }
 
-static struct file_operations proc_cgroupstats_operations = {
+static const struct file_operations proc_cgroupstats_operations = {
 	.open = cgroupstats_open,
 	.read = seq_read,
 	.llseek = seq_lseek,
@@ -3320,13 +3672,11 @@ int cgroup_is_descendant(const struct cgroup *cgrp, struct task_struct *task)
 {
 	int ret;
 	struct cgroup *target;
-	int subsys_id;
 
 	if (cgrp == dummytop)
 		return 1;
 
-	get_first_subsys(cgrp, NULL, &subsys_id);
-	target = task_cgroup(task, subsys_id);
+	target = task_cgroup_from_root(task, cgrp->root);
 	while (cgrp != target && cgrp!= cgrp->top_cgroup)
 		cgrp = cgrp->parent;
 	ret = (cgrp == target);
@@ -3358,8 +3708,10 @@ static void check_for_release(struct cgroup *cgrp)
 void __css_put(struct cgroup_subsys_state *css)
 {
 	struct cgroup *cgrp = css->cgroup;
+	int val;
 	rcu_read_lock();
-	if (atomic_dec_return(&css->refcnt) == 1) {
+	val = atomic_dec_return(&css->refcnt);
+	if (val == 1) {
 		if (notify_on_release(cgrp)) {
 			set_bit(CGRP_RELEASABLE, &cgrp->flags);
 			check_for_release(cgrp);
@@ -3367,6 +3719,7 @@ void __css_put(struct cgroup_subsys_state *css)
 		cgroup_wakeup_rmdir_waiter(cgrp);
 	}
 	rcu_read_unlock();
+	WARN_ON_ONCE(val < 1);
 }
 
 /*
@@ -3693,3 +4046,154 @@ css_get_next(struct cgroup_subsys *ss, int id,
 	return ret;
 }
 
+#ifdef CONFIG_CGROUP_DEBUG
+static struct cgroup_subsys_state *debug_create(struct cgroup_subsys *ss,
+						   struct cgroup *cont)
+{
+	struct cgroup_subsys_state *css = kzalloc(sizeof(*css), GFP_KERNEL);
+
+	if (!css)
+		return ERR_PTR(-ENOMEM);
+
+	return css;
+}
+
+static void debug_destroy(struct cgroup_subsys *ss, struct cgroup *cont)
+{
+	kfree(cont->subsys[debug_subsys_id]);
+}
+
+static u64 cgroup_refcount_read(struct cgroup *cont, struct cftype *cft)
+{
+	return atomic_read(&cont->count);
+}
+
+static u64 debug_taskcount_read(struct cgroup *cont, struct cftype *cft)
+{
+	return cgroup_task_count(cont);
+}
+
+static u64 current_css_set_read(struct cgroup *cont, struct cftype *cft)
+{
+	return (u64)(unsigned long)current->cgroups;
+}
+
+static u64 current_css_set_refcount_read(struct cgroup *cont,
+					   struct cftype *cft)
+{
+	u64 count;
+
+	rcu_read_lock();
+	count = atomic_read(&current->cgroups->refcount);
+	rcu_read_unlock();
+	return count;
+}
+
+static int current_css_set_cg_links_read(struct cgroup *cont,
+					 struct cftype *cft,
+					 struct seq_file *seq)
+{
+	struct cg_cgroup_link *link;
+	struct css_set *cg;
+
+	read_lock(&css_set_lock);
+	rcu_read_lock();
+	cg = rcu_dereference(current->cgroups);
+	list_for_each_entry(link, &cg->cg_links, cg_link_list) {
+		struct cgroup *c = link->cgrp;
+		const char *name;
+
+		if (c->dentry)
+			name = c->dentry->d_name.name;
+		else
+			name = "?";
+		seq_printf(seq, "Root %d group %s\n",
+			   c->root->hierarchy_id, name);
+	}
+	rcu_read_unlock();
+	read_unlock(&css_set_lock);
+	return 0;
+}
+
+#define MAX_TASKS_SHOWN_PER_CSS 25
+static int cgroup_css_links_read(struct cgroup *cont,
+				 struct cftype *cft,
+				 struct seq_file *seq)
+{
+	struct cg_cgroup_link *link;
+
+	read_lock(&css_set_lock);
+	list_for_each_entry(link, &cont->css_sets, cgrp_link_list) {
+		struct css_set *cg = link->cg;
+		struct task_struct *task;
+		int count = 0;
+		seq_printf(seq, "css_set %p\n", cg);
+		list_for_each_entry(task, &cg->tasks, cg_list) {
+			if (count++ > MAX_TASKS_SHOWN_PER_CSS) {
+				seq_puts(seq, "  ...\n");
+				break;
+			} else {
+				seq_printf(seq, "  task %d\n",
+					   task_pid_vnr(task));
+			}
+		}
+	}
+	read_unlock(&css_set_lock);
+	return 0;
+}
+
+static u64 releasable_read(struct cgroup *cgrp, struct cftype *cft)
+{
+	return test_bit(CGRP_RELEASABLE, &cgrp->flags);
+}
+
+static struct cftype debug_files[] =  {
+	{
+		.name = "cgroup_refcount",
+		.read_u64 = cgroup_refcount_read,
+	},
+	{
+		.name = "taskcount",
+		.read_u64 = debug_taskcount_read,
+	},
+
+	{
+		.name = "current_css_set",
+		.read_u64 = current_css_set_read,
+	},
+
+	{
+		.name = "current_css_set_refcount",
+		.read_u64 = current_css_set_refcount_read,
+	},
+
+	{
+		.name = "current_css_set_cg_links",
+		.read_seq_string = current_css_set_cg_links_read,
+	},
+
+	{
+		.name = "cgroup_css_links",
+		.read_seq_string = cgroup_css_links_read,
+	},
+
+	{
+		.name = "releasable",
+		.read_u64 = releasable_read,
+	},
+};
+
+static int debug_populate(struct cgroup_subsys *ss, struct cgroup *cont)
+{
+	return cgroup_add_files(cont, ss, debug_files,
+				ARRAY_SIZE(debug_files));
+}
+
+struct cgroup_subsys debug_subsys = {
+	.name = "debug",
+	.create = debug_create,
+	.destroy = debug_destroy,
+	.populate = debug_populate,
+	.subsys_id = debug_subsys_id,
+};
+#endif /* CONFIG_CGROUP_DEBUG */
diff --git a/kernel/cgroup_debug.c b/kernel/cgroup_debug.c
deleted file mode 100644
index 0c92d797baa..00000000000
--- a/kernel/cgroup_debug.c
+++ /dev/null
@@ -1,105 +0,0 @@
-/*
- * kernel/cgroup_debug.c - Example cgroup subsystem that
- * exposes debug info
- *
- * Copyright (C) Google Inc, 2007
- *
- * Developed by Paul Menage (menage@google.com)
- *
- */
-
-#include <linux/cgroup.h>
-#include <linux/fs.h>
-#include <linux/slab.h>
-#include <linux/rcupdate.h>
-
-#include <asm/atomic.h>
-
-static struct cgroup_subsys_state *debug_create(struct cgroup_subsys *ss,
-						   struct cgroup *cont)
-{
-	struct cgroup_subsys_state *css = kzalloc(sizeof(*css), GFP_KERNEL);
-
-	if (!css)
-		return ERR_PTR(-ENOMEM);
-
-	return css;
-}
-
-static void debug_destroy(struct cgroup_subsys *ss, struct cgroup *cont)
-{
-	kfree(cont->subsys[debug_subsys_id]);
-}
-
-static u64 cgroup_refcount_read(struct cgroup *cont, struct cftype *cft)
-{
-	return atomic_read(&cont->count);
-}
-
-static u64 taskcount_read(struct cgroup *cont, struct cftype *cft)
-{
-	u64 count;
-
-	count = cgroup_task_count(cont);
-	return count;
-}
-
-static u64 current_css_set_read(struct cgroup *cont, struct cftype *cft)
-{
-	return (u64)(long)current->cgroups;
-}
-
-static u64 current_css_set_refcount_read(struct cgroup *cont,
-					   struct cftype *cft)
-{
-	u64 count;
-
-	rcu_read_lock();
-	count = atomic_read(&current->cgroups->refcount);
-	rcu_read_unlock();
-	return count;
-}
-
-static u64 releasable_read(struct cgroup *cgrp, struct cftype *cft)
-{
-	return test_bit(CGRP_RELEASABLE, &cgrp->flags);
-}
-
-static struct cftype files[] =  {
-	{
-		.name = "cgroup_refcount",
-		.read_u64 = cgroup_refcount_read,
-	},
-	{
-		.name = "taskcount",
-		.read_u64 = taskcount_read,
-	},
-
-	{
-		.name = "current_css_set",
-		.read_u64 = current_css_set_read,
-	},
-
-	{
-		.name = "current_css_set_refcount",
-		.read_u64 = current_css_set_refcount_read,
-	},
-
-	{
-		.name = "releasable",
-		.read_u64 = releasable_read,
-	},
-};
-
-static int debug_populate(struct cgroup_subsys *ss, struct cgroup *cont)
-{
-	return cgroup_add_files(cont, ss, files, ARRAY_SIZE(files));
-}
-
-struct cgroup_subsys debug_subsys = {
-	.name = "debug",
-	.create = debug_create,
-	.destroy = debug_destroy,
-	.populate = debug_populate,
-	.subsys_id = debug_subsys_id,
-};
diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c
index fb249e2bcad..59e9ef6aab4 100644
--- a/kernel/cgroup_freezer.c
+++ b/kernel/cgroup_freezer.c
@@ -159,7 +159,7 @@ static bool is_task_frozen_enough(struct task_struct *task)
  */
 static int freezer_can_attach(struct cgroup_subsys *ss,
 			      struct cgroup *new_cgroup,
-			      struct task_struct *task)
+			      struct task_struct *task, bool threadgroup)
 {
 	struct freezer *freezer;
 
@@ -177,6 +177,19 @@ static int freezer_can_attach(struct cgroup_subsys *ss,
 	if (freezer->state == CGROUP_FROZEN)
 		return -EBUSY;
 
+	if (threadgroup) {
+		struct task_struct *c;
+
+		rcu_read_lock();
+		list_for_each_entry_rcu(c, &task->thread_group, thread_group) {
+			if (is_task_frozen_enough(c)) {
+				rcu_read_unlock();
+				return -EBUSY;
+			}
+		}
+		rcu_read_unlock();
+	}
+
 	return 0;
 }
 
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index b81f7f096e1..d247381e737 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -1324,9 +1324,10 @@ static int fmeter_getrate(struct fmeter *fmp)
 static cpumask_var_t cpus_attach;
 
 /* Called by cgroups to determine if a cpuset is usable; cgroup_mutex held */
-static int cpuset_can_attach(struct cgroup_subsys *ss,
-			     struct cgroup *cont, struct task_struct *tsk)
+static int cpuset_can_attach(struct cgroup_subsys *ss, struct cgroup *cont,
+			     struct task_struct *tsk, bool threadgroup)
 {
+	int ret;
 	struct cpuset *cs = cgroup_cs(cont);
 
 	if (cpumask_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed))
@@ -1343,18 +1344,51 @@ static int cpuset_can_attach(struct cgroup_subsys *ss,
 	if (tsk->flags & PF_THREAD_BOUND)
 		return -EINVAL;
 
-	return security_task_setscheduler(tsk, 0, NULL);
+	ret = security_task_setscheduler(tsk, 0, NULL);
+	if (ret)
+		return ret;
+	if (threadgroup) {
+		struct task_struct *c;
+
+		rcu_read_lock();
+		list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) {
+			ret = security_task_setscheduler(c, 0, NULL);
+			if (ret) {
+				rcu_read_unlock();
+				return ret;
+			}
+		}
+		rcu_read_unlock();
+	}
+	return 0;
+}
+
+static void cpuset_attach_task(struct task_struct *tsk, nodemask_t *to,
+			       struct cpuset *cs)
+{
+	int err;
+	/*
+	 * can_attach beforehand should guarantee that this doesn't fail.
+	 * TODO: have a better way to handle failure here
+	 */
+	err = set_cpus_allowed_ptr(tsk, cpus_attach);
+	WARN_ON_ONCE(err);
+
+	task_lock(tsk);
+	cpuset_change_task_nodemask(tsk, to);
+	task_unlock(tsk);
+	cpuset_update_task_spread_flag(cs, tsk);
+
 }
 
-static void cpuset_attach(struct cgroup_subsys *ss,
-			  struct cgroup *cont, struct cgroup *oldcont,
-			  struct task_struct *tsk)
+static void cpuset_attach(struct cgroup_subsys *ss, struct cgroup *cont,
+			  struct cgroup *oldcont, struct task_struct *tsk,
+			  bool threadgroup)
 {
 	nodemask_t from, to;
 	struct mm_struct *mm;
 	struct cpuset *cs = cgroup_cs(cont);
 	struct cpuset *oldcs = cgroup_cs(oldcont);
-	int err;
 
 	if (cs == &top_cpuset) {
 		cpumask_copy(cpus_attach, cpu_possible_mask);
@@ -1363,15 +1397,19 @@ static void cpuset_attach(struct cgroup_subsys *ss,
 		guarantee_online_cpus(cs, cpus_attach);
 		guarantee_online_mems(cs, &to);
 	}
-	err = set_cpus_allowed_ptr(tsk, cpus_attach);
-	if (err)
-		return;
 
-	task_lock(tsk);
-	cpuset_change_task_nodemask(tsk, &to);
-	task_unlock(tsk);
-	cpuset_update_task_spread_flag(cs, tsk);
+	/* do per-task migration stuff possibly for each in the threadgroup */
+	cpuset_attach_task(tsk, &to, cs);
+	if (threadgroup) {
+		struct task_struct *c;
+		rcu_read_lock();
+		list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) {
+			cpuset_attach_task(c, &to, cs);
+		}
+		rcu_read_unlock();
+	}
 
+	/* change mm; only needs to be done once even if threadgroup */
 	from = oldcs->mems_allowed;
 	to = cs->mems_allowed;
 	mm = get_task_mm(tsk);
diff --git a/kernel/cred.c b/kernel/cred.c
index d7f7a01082e..dd76cfe5f5b 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -782,6 +782,25 @@ EXPORT_SYMBOL(set_create_files_as);
 
 #ifdef CONFIG_DEBUG_CREDENTIALS
 
+bool creds_are_invalid(const struct cred *cred)
+{
+	if (cred->magic != CRED_MAGIC)
+		return true;
+	if (atomic_read(&cred->usage) < atomic_read(&cred->subscribers))
+		return true;
+#ifdef CONFIG_SECURITY_SELINUX
+	if (selinux_is_enabled()) {
+		if ((unsigned long) cred->security < PAGE_SIZE)
+			return true;
+		if ((*(u32 *)cred->security & 0xffffff00) ==
+		    (POISON_FREE << 24 | POISON_FREE << 16 | POISON_FREE << 8))
+			return true;
+	}
+#endif
+	return false;
+}
+EXPORT_SYMBOL(creds_are_invalid);
+
 /*
  * dump invalid credentials
  */
diff --git a/kernel/delayacct.c b/kernel/delayacct.c
index abb6e17505e..ead9b610aa7 100644
--- a/kernel/delayacct.c
+++ b/kernel/delayacct.c
@@ -15,6 +15,7 @@
 
 #include <linux/sched.h>
 #include <linux/slab.h>
+#include <linux/taskstats.h>
 #include <linux/time.h>
 #include <linux/sysctl.h>
 #include <linux/delayacct.h>
diff --git a/kernel/exit.c b/kernel/exit.c
index ae5d8660ddf..e61891f8012 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -47,7 +47,7 @@
 #include <linux/tracehook.h>
 #include <linux/fs_struct.h>
 #include <linux/init_task.h>
-#include <linux/perf_counter.h>
+#include <linux/perf_event.h>
 #include <trace/events/sched.h>
 
 #include <asm/uaccess.h>
@@ -154,8 +154,8 @@ static void delayed_put_task_struct(struct rcu_head *rhp)
 {
 	struct task_struct *tsk = container_of(rhp, struct task_struct, rcu);
 
-#ifdef CONFIG_PERF_COUNTERS
-	WARN_ON_ONCE(tsk->perf_counter_ctxp);
+#ifdef CONFIG_PERF_EVENTS
+	WARN_ON_ONCE(tsk->perf_event_ctxp);
 #endif
 	trace_sched_process_free(tsk);
 	put_task_struct(tsk);
@@ -359,8 +359,10 @@ void __set_special_pids(struct pid *pid)
 {
 	struct task_struct *curr = current->group_leader;
 
-	if (task_session(curr) != pid)
+	if (task_session(curr) != pid) {
 		change_pid(curr, PIDTYPE_SID, pid);
+		proc_sid_connector(curr);
+	}
 
 	if (task_pgrp(curr) != pid)
 		change_pid(curr, PIDTYPE_PGID, pid);
@@ -945,6 +947,8 @@ NORET_TYPE void do_exit(long code)
 	if (group_dead) {
 		hrtimer_cancel(&tsk->signal->real_timer);
 		exit_itimers(tsk->signal);
+		if (tsk->mm)
+			setmax_mm_hiwater_rss(&tsk->signal->maxrss, tsk->mm);
 	}
 	acct_collect(code, group_dead);
 	if (group_dead)
@@ -972,8 +976,6 @@ NORET_TYPE void do_exit(long code)
 		disassociate_ctty(1);
 
 	module_put(task_thread_info(tsk)->exec_domain->module);
-	if (tsk->binfmt)
-		module_put(tsk->binfmt->module);
 
 	proc_exit_connector(tsk);
 
@@ -981,7 +983,7 @@ NORET_TYPE void do_exit(long code)
 	 * Flush inherited counters to the parent - before the parent
 	 * gets woken up by child-exit notifications.
 	 */
-	perf_counter_exit_task(tsk);
+	perf_event_exit_task(tsk);
 
 	exit_notify(tsk, group_dead);
 #ifdef CONFIG_NUMA
@@ -989,8 +991,6 @@ NORET_TYPE void do_exit(long code)
 	tsk->mempolicy = NULL;
 #endif
 #ifdef CONFIG_FUTEX
-	if (unlikely(!list_empty(&tsk->pi_state_list)))
-		exit_pi_state_list(tsk);
 	if (unlikely(current->pi_state_cache))
 		kfree(current->pi_state_cache);
 #endif
@@ -1093,28 +1093,28 @@ struct wait_opts {
 	int __user		*wo_stat;
 	struct rusage __user	*wo_rusage;
 
+	wait_queue_t		child_wait;
 	int			notask_error;
 };
 
-static struct pid *task_pid_type(struct task_struct *task, enum pid_type type)
+static inline
+struct pid *task_pid_type(struct task_struct *task, enum pid_type type)
 {
-	struct pid *pid = NULL;
-	if (type == PIDTYPE_PID)
-		pid = task->pids[type].pid;
-	else if (type < PIDTYPE_MAX)
-		pid = task->group_leader->pids[type].pid;
-	return pid;
+	if (type != PIDTYPE_PID)
+		task = task->group_leader;
+	return task->pids[type].pid;
 }
 
-static int eligible_child(struct wait_opts *wo, struct task_struct *p)
+static int eligible_pid(struct wait_opts *wo, struct task_struct *p)
 {
-	int err;
-
-	if (wo->wo_type < PIDTYPE_MAX) {
-		if (task_pid_type(p, wo->wo_type) != wo->wo_pid)
-			return 0;
-	}
+	return	wo->wo_type == PIDTYPE_MAX ||
+		task_pid_type(p, wo->wo_type) == wo->wo_pid;
+}
 
+static int eligible_child(struct wait_opts *wo, struct task_struct *p)
+{
+	if (!eligible_pid(wo, p))
+		return 0;
 	/* Wait for all children (clone and not) if __WALL is set;
 	 * otherwise, wait for clone children *only* if __WCLONE is
 	 * set; otherwise, wait for non-clone children *only*.  (Note:
@@ -1124,10 +1124,6 @@ static int eligible_child(struct wait_opts *wo, struct task_struct *p)
 	    && !(wo->wo_flags & __WALL))
 		return 0;
 
-	err = security_task_wait(p);
-	if (err)
-		return err;
-
 	return 1;
 }
 
@@ -1140,18 +1136,20 @@ static int wait_noreap_copyout(struct wait_opts *wo, struct task_struct *p,
 
 	put_task_struct(p);
 	infop = wo->wo_info;
-	if (!retval)
-		retval = put_user(SIGCHLD, &infop->si_signo);
-	if (!retval)
-		retval = put_user(0, &infop->si_errno);
-	if (!retval)
-		retval = put_user((short)why, &infop->si_code);
-	if (!retval)
-		retval = put_user(pid, &infop->si_pid);
-	if (!retval)
-		retval = put_user(uid, &infop->si_uid);
-	if (!retval)
-		retval = put_user(status, &infop->si_status);
+	if (infop) {
+		if (!retval)
+			retval = put_user(SIGCHLD, &infop->si_signo);
+		if (!retval)
+			retval = put_user(0, &infop->si_errno);
+		if (!retval)
+			retval = put_user((short)why, &infop->si_code);
+		if (!retval)
+			retval = put_user(pid, &infop->si_pid);
+		if (!retval)
+			retval = put_user(uid, &infop->si_uid);
+		if (!retval)
+			retval = put_user(status, &infop->si_status);
+	}
 	if (!retval)
 		retval = pid;
 	return retval;
@@ -1208,6 +1206,7 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p)
 	if (likely(!traced) && likely(!task_detached(p))) {
 		struct signal_struct *psig;
 		struct signal_struct *sig;
+		unsigned long maxrss;
 
 		/*
 		 * The resource counters for the group leader are in its
@@ -1256,6 +1255,9 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p)
 		psig->coublock +=
 			task_io_get_oublock(p) +
 			sig->oublock + sig->coublock;
+		maxrss = max(sig->maxrss, sig->cmaxrss);
+		if (psig->cmaxrss < maxrss)
+			psig->cmaxrss = maxrss;
 		task_io_accounting_add(&psig->ioac, &p->ioac);
 		task_io_accounting_add(&psig->ioac, &sig->ioac);
 		spin_unlock_irq(&p->real_parent->sighand->siglock);
@@ -1477,13 +1479,14 @@ static int wait_task_continued(struct wait_opts *wo, struct task_struct *p)
  * then ->notask_error is 0 if @p is an eligible child,
  * or another error from security_task_wait(), or still -ECHILD.
  */
-static int wait_consider_task(struct wait_opts *wo, struct task_struct *parent,
-				int ptrace, struct task_struct *p)
+static int wait_consider_task(struct wait_opts *wo, int ptrace,
+				struct task_struct *p)
 {
 	int ret = eligible_child(wo, p);
 	if (!ret)
 		return ret;
 
+	ret = security_task_wait(p);
 	if (unlikely(ret < 0)) {
 		/*
 		 * If we have not yet seen any eligible child,
@@ -1545,7 +1548,7 @@ static int do_wait_thread(struct wait_opts *wo, struct task_struct *tsk)
 		 * Do not consider detached threads.
 		 */
 		if (!task_detached(p)) {
-			int ret = wait_consider_task(wo, tsk, 0, p);
+			int ret = wait_consider_task(wo, 0, p);
 			if (ret)
 				return ret;
 		}
@@ -1559,7 +1562,7 @@ static int ptrace_do_wait(struct wait_opts *wo, struct task_struct *tsk)
 	struct task_struct *p;
 
 	list_for_each_entry(p, &tsk->ptraced, ptrace_entry) {
-		int ret = wait_consider_task(wo, tsk, 1, p);
+		int ret = wait_consider_task(wo, 1, p);
 		if (ret)
 			return ret;
 	}
@@ -1567,15 +1570,38 @@ static int ptrace_do_wait(struct wait_opts *wo, struct task_struct *tsk)
 	return 0;
 }
 
+static int child_wait_callback(wait_queue_t *wait, unsigned mode,
+				int sync, void *key)
+{
+	struct wait_opts *wo = container_of(wait, struct wait_opts,
+						child_wait);
+	struct task_struct *p = key;
+
+	if (!eligible_pid(wo, p))
+		return 0;
+
+	if ((wo->wo_flags & __WNOTHREAD) && wait->private != p->parent)
+		return 0;
+
+	return default_wake_function(wait, mode, sync, key);
+}
+
+void __wake_up_parent(struct task_struct *p, struct task_struct *parent)
+{
+	__wake_up_sync_key(&parent->signal->wait_chldexit,
+				TASK_INTERRUPTIBLE, 1, p);
+}
+
 static long do_wait(struct wait_opts *wo)
 {
-	DECLARE_WAITQUEUE(wait, current);
 	struct task_struct *tsk;
 	int retval;
 
 	trace_sched_process_wait(wo->wo_pid);
 
-	add_wait_queue(&current->signal->wait_chldexit,&wait);
+	init_waitqueue_func_entry(&wo->child_wait, child_wait_callback);
+	wo->child_wait.private = current;
+	add_wait_queue(&current->signal->wait_chldexit, &wo->child_wait);
 repeat:
 	/*
 	 * If there is nothing that can match our critiera just get out.
@@ -1616,32 +1642,7 @@ notask:
 	}
 end:
 	__set_current_state(TASK_RUNNING);
-	remove_wait_queue(&current->signal->wait_chldexit,&wait);
-	if (wo->wo_info) {
-		struct siginfo __user *infop = wo->wo_info;
-
-		if (retval > 0)
-			retval = 0;
-		else {
-			/*
-			 * For a WNOHANG return, clear out all the fields
-			 * we would set so the user can easily tell the
-			 * difference.
-			 */
-			if (!retval)
-				retval = put_user(0, &infop->si_signo);
-			if (!retval)
-				retval = put_user(0, &infop->si_errno);
-			if (!retval)
-				retval = put_user(0, &infop->si_code);
-			if (!retval)
-				retval = put_user(0, &infop->si_pid);
-			if (!retval)
-				retval = put_user(0, &infop->si_uid);
-			if (!retval)
-				retval = put_user(0, &infop->si_status);
-		}
-	}
+	remove_wait_queue(&current->signal->wait_chldexit, &wo->child_wait);
 	return retval;
 }
 
@@ -1686,6 +1687,29 @@ SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *,
 	wo.wo_stat	= NULL;
 	wo.wo_rusage	= ru;
 	ret = do_wait(&wo);
+
+	if (ret > 0) {
+		ret = 0;
+	} else if (infop) {
+		/*
+		 * For a WNOHANG return, clear out all the fields
+		 * we would set so the user can easily tell the
+		 * difference.
+		 */
+		if (!ret)
+			ret = put_user(0, &infop->si_signo);
+		if (!ret)
+			ret = put_user(0, &infop->si_errno);
+		if (!ret)
+			ret = put_user(0, &infop->si_code);
+		if (!ret)
+			ret = put_user(0, &infop->si_pid);
+		if (!ret)
+			ret = put_user(0, &infop->si_uid);
+		if (!ret)
+			ret = put_user(0, &infop->si_status);
+	}
+
 	put_pid(pid);
 
 	/* avoid REGPARM breakage on x86: */
diff --git a/kernel/fork.c b/kernel/fork.c
index bfee931ee3f..4c20fff8c13 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -49,6 +49,7 @@
 #include <linux/ftrace.h>
 #include <linux/profile.h>
 #include <linux/rmap.h>
+#include <linux/ksm.h>
 #include <linux/acct.h>
 #include <linux/tsacct_kern.h>
 #include <linux/cn_proc.h>
@@ -61,7 +62,8 @@
 #include <linux/blkdev.h>
 #include <linux/fs_struct.h>
 #include <linux/magic.h>
-#include <linux/perf_counter.h>
+#include <linux/perf_event.h>
+#include <linux/posix-timers.h>
 
 #include <asm/pgtable.h>
 #include <asm/pgalloc.h>
@@ -136,9 +138,17 @@ struct kmem_cache *vm_area_cachep;
 /* SLAB cache for mm_struct structures (tsk->mm) */
 static struct kmem_cache *mm_cachep;
 
+static void account_kernel_stack(struct thread_info *ti, int account)
+{
+	struct zone *zone = page_zone(virt_to_page(ti));
+
+	mod_zone_page_state(zone, NR_KERNEL_STACK, account);
+}
+
 void free_task(struct task_struct *tsk)
 {
 	prop_local_destroy_single(&tsk->dirties);
+	account_kernel_stack(tsk->stack, -1);
 	free_thread_info(tsk->stack);
 	rt_mutex_debug_task_free(tsk);
 	ftrace_graph_exit_task(tsk);
@@ -253,6 +263,9 @@ static struct task_struct *dup_task_struct(struct task_struct *orig)
 	tsk->btrace_seq = 0;
 #endif
 	tsk->splice_pipe = NULL;
+
+	account_kernel_stack(ti, 1);
+
 	return tsk;
 
 out:
@@ -288,6 +301,9 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
 	rb_link = &mm->mm_rb.rb_node;
 	rb_parent = NULL;
 	pprev = &mm->mmap;
+	retval = ksm_fork(mm, oldmm);
+	if (retval)
+		goto out;
 
 	for (mpnt = oldmm->mmap; mpnt; mpnt = mpnt->vm_next) {
 		struct file *file;
@@ -418,22 +434,30 @@ __setup("coredump_filter=", coredump_filter_setup);
 
 #include <linux/init_task.h>
 
+static void mm_init_aio(struct mm_struct *mm)
+{
+#ifdef CONFIG_AIO
+	spin_lock_init(&mm->ioctx_lock);
+	INIT_HLIST_HEAD(&mm->ioctx_list);
+#endif
+}
+
 static struct mm_struct * mm_init(struct mm_struct * mm, struct task_struct *p)
 {
 	atomic_set(&mm->mm_users, 1);
 	atomic_set(&mm->mm_count, 1);
 	init_rwsem(&mm->mmap_sem);
 	INIT_LIST_HEAD(&mm->mmlist);
-	mm->flags = (current->mm) ? current->mm->flags : default_dump_filter;
+	mm->flags = (current->mm) ?
+		(current->mm->flags & MMF_INIT_MASK) : default_dump_filter;
 	mm->core_state = NULL;
 	mm->nr_ptes = 0;
 	set_mm_counter(mm, file_rss, 0);
 	set_mm_counter(mm, anon_rss, 0);
 	spin_lock_init(&mm->page_table_lock);
-	spin_lock_init(&mm->ioctx_lock);
-	INIT_HLIST_HEAD(&mm->ioctx_list);
 	mm->free_area_cache = TASK_UNMAPPED_BASE;
 	mm->cached_hole_size = ~0UL;
+	mm_init_aio(mm);
 	mm_init_owner(mm, p);
 
 	if (likely(!mm_alloc_pgd(mm))) {
@@ -485,6 +509,7 @@ void mmput(struct mm_struct *mm)
 
 	if (atomic_dec_and_test(&mm->mm_users)) {
 		exit_aio(mm);
+		ksm_exit(mm);
 		exit_mmap(mm);
 		set_mm_exe_file(mm, NULL);
 		if (!list_empty(&mm->mmlist)) {
@@ -493,6 +518,8 @@ void mmput(struct mm_struct *mm)
 			spin_unlock(&mmlist_lock);
 		}
 		put_swap_token(mm);
+		if (mm->binfmt)
+			module_put(mm->binfmt->module);
 		mmdrop(mm);
 	}
 }
@@ -543,12 +570,18 @@ void mm_release(struct task_struct *tsk, struct mm_struct *mm)
 
 	/* Get rid of any futexes when releasing the mm */
 #ifdef CONFIG_FUTEX
-	if (unlikely(tsk->robust_list))
+	if (unlikely(tsk->robust_list)) {
 		exit_robust_list(tsk);
+		tsk->robust_list = NULL;
+	}
 #ifdef CONFIG_COMPAT
-	if (unlikely(tsk->compat_robust_list))
+	if (unlikely(tsk->compat_robust_list)) {
 		compat_exit_robust_list(tsk);
+		tsk->compat_robust_list = NULL;
+	}
 #endif
+	if (unlikely(!list_empty(&tsk->pi_state_list)))
+		exit_pi_state_list(tsk);
 #endif
 
 	/* Get rid of any cached register state */
@@ -618,9 +651,14 @@ struct mm_struct *dup_mm(struct task_struct *tsk)
 	mm->hiwater_rss = get_mm_rss(mm);
 	mm->hiwater_vm = mm->total_vm;
 
+	if (mm->binfmt && !try_module_get(mm->binfmt->module))
+		goto free_pt;
+
 	return mm;
 
 free_pt:
+	/* don't put binfmt in mmput, we haven't got module yet */
+	mm->binfmt = NULL;
 	mmput(mm);
 
 fail_nomem:
@@ -788,10 +826,10 @@ static void posix_cpu_timers_init_group(struct signal_struct *sig)
 	thread_group_cputime_init(sig);
 
 	/* Expiration times and increments. */
-	sig->it_virt_expires = cputime_zero;
-	sig->it_virt_incr = cputime_zero;
-	sig->it_prof_expires = cputime_zero;
-	sig->it_prof_incr = cputime_zero;
+	sig->it[CPUCLOCK_PROF].expires = cputime_zero;
+	sig->it[CPUCLOCK_PROF].incr = cputime_zero;
+	sig->it[CPUCLOCK_VIRT].expires = cputime_zero;
+	sig->it[CPUCLOCK_VIRT].incr = cputime_zero;
 
 	/* Cached expiration times. */
 	sig->cputime_expires.prof_exp = cputime_zero;
@@ -849,6 +887,7 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
 	sig->nvcsw = sig->nivcsw = sig->cnvcsw = sig->cnivcsw = 0;
 	sig->min_flt = sig->maj_flt = sig->cmin_flt = sig->cmaj_flt = 0;
 	sig->inblock = sig->oublock = sig->cinblock = sig->coublock = 0;
+	sig->maxrss = sig->cmaxrss = 0;
 	task_io_accounting_init(&sig->ioac);
 	sig->sum_sched_runtime = 0;
 	taskstats_tgid_init(sig);
@@ -863,6 +902,8 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
 
 	tty_audit_fork(sig);
 
+	sig->oom_adj = current->signal->oom_adj;
+
 	return 0;
 }
 
@@ -958,6 +999,16 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 	if ((clone_flags & CLONE_SIGHAND) && !(clone_flags & CLONE_VM))
 		return ERR_PTR(-EINVAL);
 
+	/*
+	 * Siblings of global init remain as zombies on exit since they are
+	 * not reaped by their parent (swapper). To solve this and to avoid
+	 * multi-rooted process trees, prevent global and container-inits
+	 * from creating siblings.
+	 */
+	if ((clone_flags & CLONE_PARENT) &&
+				current->signal->flags & SIGNAL_UNKILLABLE)
+		return ERR_PTR(-EINVAL);
+
 	retval = security_task_create(clone_flags);
 	if (retval)
 		goto fork_out;
@@ -999,9 +1050,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 	if (!try_module_get(task_thread_info(p)->exec_domain->module))
 		goto bad_fork_cleanup_count;
 
-	if (p->binfmt && !try_module_get(p->binfmt->module))
-		goto bad_fork_cleanup_put_domain;
-
 	p->did_exec = 0;
 	delayacct_tsk_init(p);	/* Must remain after dup_task_struct() */
 	copy_flags(clone_flags, p);
@@ -1075,10 +1123,12 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 
 	p->bts = NULL;
 
+	p->stack_start = stack_start;
+
 	/* Perform scheduler related setup. Assign this task to a CPU. */
 	sched_fork(p, clone_flags);
 
-	retval = perf_counter_init_task(p);
+	retval = perf_event_init_task(p);
 	if (retval)
 		goto bad_fork_cleanup_policy;
 
@@ -1253,7 +1303,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 	write_unlock_irq(&tasklist_lock);
 	proc_fork_connector(p);
 	cgroup_post_fork(p);
-	perf_counter_fork(p);
+	perf_event_fork(p);
 	return p;
 
 bad_fork_free_pid:
@@ -1280,16 +1330,13 @@ bad_fork_cleanup_semundo:
 bad_fork_cleanup_audit:
 	audit_free(p);
 bad_fork_cleanup_policy:
-	perf_counter_free_task(p);
+	perf_event_free_task(p);
 #ifdef CONFIG_NUMA
 	mpol_put(p->mempolicy);
 bad_fork_cleanup_cgroup:
 #endif
 	cgroup_exit(p, cgroup_callbacks_done);
 	delayacct_tsk_free(p);
-	if (p->binfmt)
-		module_put(p->binfmt->module);
-bad_fork_cleanup_put_domain:
 	module_put(task_thread_info(p)->exec_domain->module);
 bad_fork_cleanup_count:
 	atomic_dec(&p->cred->user->processes);
diff --git a/kernel/futex.c b/kernel/futex.c
index 248dd119a86..4949d336d88 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -89,36 +89,36 @@ struct futex_pi_state {
 	union futex_key key;
 };
 
-/*
- * We use this hashed waitqueue instead of a normal wait_queue_t, so
+/**
+ * struct futex_q - The hashed futex queue entry, one per waiting task
+ * @task:		the task waiting on the futex
+ * @lock_ptr:		the hash bucket lock
+ * @key:		the key the futex is hashed on
+ * @pi_state:		optional priority inheritance state
+ * @rt_waiter:		rt_waiter storage for use with requeue_pi
+ * @requeue_pi_key:	the requeue_pi target futex key
+ * @bitset:		bitset for the optional bitmasked wakeup
+ *
+ * We use this hashed waitqueue, instead of a normal wait_queue_t, so
  * we can wake only the relevant ones (hashed queues may be shared).
  *
  * A futex_q has a woken state, just like tasks have TASK_RUNNING.
  * It is considered woken when plist_node_empty(&q->list) || q->lock_ptr == 0.
  * The order of wakup is always to make the first condition true, then
- * wake up q->waiter, then make the second condition true.
+ * the second.
+ *
+ * PI futexes are typically woken before they are removed from the hash list via
+ * the rt_mutex code. See unqueue_me_pi().
  */
 struct futex_q {
 	struct plist_node list;
-	/* Waiter reference */
-	struct task_struct *task;
 
-	/* Which hash list lock to use: */
+	struct task_struct *task;
 	spinlock_t *lock_ptr;
-
-	/* Key which the futex is hashed on: */
 	union futex_key key;
-
-	/* Optional priority inheritance state: */
 	struct futex_pi_state *pi_state;
-
-	/* rt_waiter storage for requeue_pi: */
 	struct rt_mutex_waiter *rt_waiter;
-
-	/* The expected requeue pi target futex key: */
 	union futex_key *requeue_pi_key;
-
-	/* Bitset for the optional bitmasked wakeup */
 	u32 bitset;
 };
 
@@ -198,11 +198,12 @@ static void drop_futex_key_refs(union futex_key *key)
 }
 
 /**
- * get_futex_key - Get parameters which are the keys for a futex.
- * @uaddr: virtual address of the futex
- * @fshared: 0 for a PROCESS_PRIVATE futex, 1 for PROCESS_SHARED
- * @key: address where result is stored.
- * @rw: mapping needs to be read/write (values: VERIFY_READ, VERIFY_WRITE)
+ * get_futex_key() - Get parameters which are the keys for a futex
+ * @uaddr:	virtual address of the futex
+ * @fshared:	0 for a PROCESS_PRIVATE futex, 1 for PROCESS_SHARED
+ * @key:	address where result is stored.
+ * @rw:		mapping needs to be read/write (values: VERIFY_READ,
+ * 		VERIFY_WRITE)
  *
  * Returns a negative error code or 0
  * The key words are stored in *key on success.
@@ -288,8 +289,8 @@ void put_futex_key(int fshared, union futex_key *key)
 	drop_futex_key_refs(key);
 }
 
-/*
- * fault_in_user_writeable - fault in user address and verify RW access
+/**
+ * fault_in_user_writeable() - Fault in user address and verify RW access
  * @uaddr:	pointer to faulting user space address
  *
  * Slow path to fixup the fault we just took in the atomic write
@@ -309,8 +310,8 @@ static int fault_in_user_writeable(u32 __user *uaddr)
 
 /**
  * futex_top_waiter() - Return the highest priority waiter on a futex
- * @hb:     the hash bucket the futex_q's reside in
- * @key:    the futex key (to distinguish it from other futex futex_q's)
+ * @hb:		the hash bucket the futex_q's reside in
+ * @key:	the futex key (to distinguish it from other futex futex_q's)
  *
  * Must be called with the hb lock held.
  */
@@ -588,7 +589,7 @@ lookup_pi_state(u32 uval, struct futex_hash_bucket *hb,
 }
 
 /**
- * futex_lock_pi_atomic() - atomic work required to acquire a pi aware futex
+ * futex_lock_pi_atomic() - Atomic work required to acquire a pi aware futex
  * @uaddr:		the pi futex user address
  * @hb:			the pi futex hash bucket
  * @key:		the futex key associated with uaddr and hb
@@ -915,8 +916,8 @@ retry:
 	hb1 = hash_futex(&key1);
 	hb2 = hash_futex(&key2);
 
-	double_lock_hb(hb1, hb2);
 retry_private:
+	double_lock_hb(hb1, hb2);
 	op_ret = futex_atomic_op_inuser(op, uaddr2);
 	if (unlikely(op_ret < 0)) {
 
@@ -1011,9 +1012,9 @@ void requeue_futex(struct futex_q *q, struct futex_hash_bucket *hb1,
 
 /**
  * requeue_pi_wake_futex() - Wake a task that acquired the lock during requeue
- * q:	the futex_q
- * key:	the key of the requeue target futex
- * hb:  the hash_bucket of the requeue target futex
+ * @q:		the futex_q
+ * @key:	the key of the requeue target futex
+ * @hb:		the hash_bucket of the requeue target futex
  *
  * During futex_requeue, with requeue_pi=1, it is possible to acquire the
  * target futex if it is uncontended or via a lock steal.  Set the futex_q key
@@ -1350,6 +1351,25 @@ static inline struct futex_hash_bucket *queue_lock(struct futex_q *q)
 	return hb;
 }
 
+static inline void
+queue_unlock(struct futex_q *q, struct futex_hash_bucket *hb)
+{
+	spin_unlock(&hb->lock);
+	drop_futex_key_refs(&q->key);
+}
+
+/**
+ * queue_me() - Enqueue the futex_q on the futex_hash_bucket
+ * @q:	The futex_q to enqueue
+ * @hb:	The destination hash bucket
+ *
+ * The hb->lock must be held by the caller, and is released here. A call to
+ * queue_me() is typically paired with exactly one call to unqueue_me().  The
+ * exceptions involve the PI related operations, which may use unqueue_me_pi()
+ * or nothing if the unqueue is done as part of the wake process and the unqueue
+ * state is implicit in the state of woken task (see futex_wait_requeue_pi() for
+ * an example).
+ */
 static inline void queue_me(struct futex_q *q, struct futex_hash_bucket *hb)
 {
 	int prio;
@@ -1373,19 +1393,17 @@ static inline void queue_me(struct futex_q *q, struct futex_hash_bucket *hb)
 	spin_unlock(&hb->lock);
 }
 
-static inline void
-queue_unlock(struct futex_q *q, struct futex_hash_bucket *hb)
-{
-	spin_unlock(&hb->lock);
-	drop_futex_key_refs(&q->key);
-}
-
-/*
- * queue_me and unqueue_me must be called as a pair, each
- * exactly once.  They are called with the hashed spinlock held.
+/**
+ * unqueue_me() - Remove the futex_q from its futex_hash_bucket
+ * @q:	The futex_q to unqueue
+ *
+ * The q->lock_ptr must not be held by the caller. A call to unqueue_me() must
+ * be paired with exactly one earlier call to queue_me().
+ *
+ * Returns:
+ *   1 - if the futex_q was still queued (and we removed unqueued it)
+ *   0 - if the futex_q was already removed by the waking thread
  */
-
-/* Return 1 if we were still queued (ie. 0 means we were woken) */
 static int unqueue_me(struct futex_q *q)
 {
 	spinlock_t *lock_ptr;
@@ -1638,17 +1656,14 @@ out:
 static void futex_wait_queue_me(struct futex_hash_bucket *hb, struct futex_q *q,
 				struct hrtimer_sleeper *timeout)
 {
-	queue_me(q, hb);
-
 	/*
-	 * There might have been scheduling since the queue_me(), as we
-	 * cannot hold a spinlock across the get_user() in case it
-	 * faults, and we cannot just set TASK_INTERRUPTIBLE state when
-	 * queueing ourselves into the futex hash. This code thus has to
-	 * rely on the futex_wake() code removing us from hash when it
-	 * wakes us up.
+	 * The task state is guaranteed to be set before another task can
+	 * wake it. set_current_state() is implemented using set_mb() and
+	 * queue_me() calls spin_unlock() upon completion, both serializing
+	 * access to the hash list and forcing another memory barrier.
 	 */
 	set_current_state(TASK_INTERRUPTIBLE);
+	queue_me(q, hb);
 
 	/* Arm the timer */
 	if (timeout) {
@@ -1658,8 +1673,8 @@ static void futex_wait_queue_me(struct futex_hash_bucket *hb, struct futex_q *q,
 	}
 
 	/*
-	 * !plist_node_empty() is safe here without any lock.
-	 * q.lock_ptr != 0 is not safe, because of ordering against wakeup.
+	 * If we have been removed from the hash list, then another task
+	 * has tried to wake us, and we can skip the call to schedule().
 	 */
 	if (likely(!plist_node_empty(&q->list))) {
 		/*
@@ -2102,7 +2117,6 @@ int handle_early_requeue_pi_wakeup(struct futex_hash_bucket *hb,
 		 * Unqueue the futex_q and determine which it was.
 		 */
 		plist_del(&q->list, &q->list.plist);
-		drop_futex_key_refs(&q->key);
 
 		if (timeout && !timeout->task)
 			ret = -ETIMEDOUT;
@@ -2114,12 +2128,12 @@ int handle_early_requeue_pi_wakeup(struct futex_hash_bucket *hb,
 
 /**
  * futex_wait_requeue_pi() - Wait on uaddr and take uaddr2
- * @uaddr:	the futex we initialyl wait on (non-pi)
+ * @uaddr:	the futex we initially wait on (non-pi)
  * @fshared:	whether the futexes are shared (1) or not (0).  They must be
  * 		the same type, no requeueing from private to shared, etc.
  * @val:	the expected value of uaddr
  * @abs_time:	absolute timeout
- * @bitset:	32 bit wakeup bitset set by userspace, defaults to all.
+ * @bitset:	32 bit wakeup bitset set by userspace, defaults to all
  * @clockrt:	whether to use CLOCK_REALTIME (1) or CLOCK_MONOTONIC (0)
  * @uaddr2:	the pi futex we will take prior to returning to user-space
  *
@@ -2246,7 +2260,7 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, int fshared,
 		res = fixup_owner(uaddr2, fshared, &q, !ret);
 		/*
 		 * If fixup_owner() returned an error, proprogate that.  If it
-		 * acquired the lock, clear our -ETIMEDOUT or -EINTR.
+		 * acquired the lock, clear -ETIMEDOUT or -EINTR.
 		 */
 		if (res)
 			ret = (res < 0) ? res : 0;
@@ -2302,9 +2316,9 @@ out:
  */
 
 /**
- * sys_set_robust_list - set the robust-futex list head of a task
- * @head: pointer to the list-head
- * @len: length of the list-head, as userspace expects
+ * sys_set_robust_list() - Set the robust-futex list head of a task
+ * @head:	pointer to the list-head
+ * @len:	length of the list-head, as userspace expects
  */
 SYSCALL_DEFINE2(set_robust_list, struct robust_list_head __user *, head,
 		size_t, len)
@@ -2323,10 +2337,10 @@ SYSCALL_DEFINE2(set_robust_list, struct robust_list_head __user *, head,
 }
 
 /**
- * sys_get_robust_list - get the robust-futex list head of a task
- * @pid: pid of the process [zero for current task]
- * @head_ptr: pointer to a list-head pointer, the kernel fills it in
- * @len_ptr: pointer to a length field, the kernel fills in the header size
+ * sys_get_robust_list() - Get the robust-futex list head of a task
+ * @pid:	pid of the process [zero for current task]
+ * @head_ptr:	pointer to a list-head pointer, the kernel fills it in
+ * @len_ptr:	pointer to a length field, the kernel fills in the header size
  */
 SYSCALL_DEFINE3(get_robust_list, int, pid,
 		struct robust_list_head __user * __user *, head_ptr,
diff --git a/kernel/gcov/Kconfig b/kernel/gcov/Kconfig
index 654efd09f6a..70a298d6da7 100644
--- a/kernel/gcov/Kconfig
+++ b/kernel/gcov/Kconfig
@@ -34,7 +34,7 @@ config GCOV_KERNEL
 config GCOV_PROFILE_ALL
 	bool "Profile entire Kernel"
 	depends on GCOV_KERNEL
-	depends on S390 || X86 || (PPC && EXPERIMENTAL)
+	depends on S390 || X86 || (PPC && EXPERIMENTAL) || MICROBLAZE
 	default n
 	---help---
 	This options activates profiling for the entire kernel.
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 05071bf6a37..3e1c36e7998 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -48,36 +48,7 @@
 
 #include <asm/uaccess.h>
 
-/**
- * ktime_get - get the monotonic time in ktime_t format
- *
- * returns the time in ktime_t format
- */
-ktime_t ktime_get(void)
-{
-	struct timespec now;
-
-	ktime_get_ts(&now);
-
-	return timespec_to_ktime(now);
-}
-EXPORT_SYMBOL_GPL(ktime_get);
-
-/**
- * ktime_get_real - get the real (wall-) time in ktime_t format
- *
- * returns the time in ktime_t format
- */
-ktime_t ktime_get_real(void)
-{
-	struct timespec now;
-
-	getnstimeofday(&now);
-
-	return timespec_to_ktime(now);
-}
-
-EXPORT_SYMBOL_GPL(ktime_get_real);
+#include <trace/events/timer.h>
 
 /*
  * The timer bases:
@@ -106,31 +77,6 @@ DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) =
 	}
 };
 
-/**
- * ktime_get_ts - get the monotonic clock in timespec format
- * @ts:		pointer to timespec variable
- *
- * The function calculates the monotonic clock from the realtime
- * clock and the wall_to_monotonic offset and stores the result
- * in normalized timespec format in the variable pointed to by @ts.
- */
-void ktime_get_ts(struct timespec *ts)
-{
-	struct timespec tomono;
-	unsigned long seq;
-
-	do {
-		seq = read_seqbegin(&xtime_lock);
-		getnstimeofday(ts);
-		tomono = wall_to_monotonic;
-
-	} while (read_seqretry(&xtime_lock, seq));
-
-	set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec,
-				ts->tv_nsec + tomono.tv_nsec);
-}
-EXPORT_SYMBOL_GPL(ktime_get_ts);
-
 /*
  * Get the coarse grained time at the softirq based on xtime and
  * wall_to_monotonic.
@@ -498,6 +444,26 @@ static inline void debug_hrtimer_activate(struct hrtimer *timer) { }
 static inline void debug_hrtimer_deactivate(struct hrtimer *timer) { }
 #endif
 
+static inline void
+debug_init(struct hrtimer *timer, clockid_t clockid,
+	   enum hrtimer_mode mode)
+{
+	debug_hrtimer_init(timer);
+	trace_hrtimer_init(timer, clockid, mode);
+}
+
+static inline void debug_activate(struct hrtimer *timer)
+{
+	debug_hrtimer_activate(timer);
+	trace_hrtimer_start(timer);
+}
+
+static inline void debug_deactivate(struct hrtimer *timer)
+{
+	debug_hrtimer_deactivate(timer);
+	trace_hrtimer_cancel(timer);
+}
+
 /* High resolution timer related functions */
 #ifdef CONFIG_HIGH_RES_TIMERS
 
@@ -543,13 +509,14 @@ static inline int hrtimer_hres_active(void)
  * next event
  * Called with interrupts disabled and base->lock held
  */
-static void hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base)
+static void
+hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base, int skip_equal)
 {
 	int i;
 	struct hrtimer_clock_base *base = cpu_base->clock_base;
-	ktime_t expires;
+	ktime_t expires, expires_next;
 
-	cpu_base->expires_next.tv64 = KTIME_MAX;
+	expires_next.tv64 = KTIME_MAX;
 
 	for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) {
 		struct hrtimer *timer;
@@ -565,10 +532,15 @@ static void hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base)
 		 */
 		if (expires.tv64 < 0)
 			expires.tv64 = 0;
-		if (expires.tv64 < cpu_base->expires_next.tv64)
-			cpu_base->expires_next = expires;
+		if (expires.tv64 < expires_next.tv64)
+			expires_next = expires;
 	}
 
+	if (skip_equal && expires_next.tv64 == cpu_base->expires_next.tv64)
+		return;
+
+	cpu_base->expires_next.tv64 = expires_next.tv64;
+
 	if (cpu_base->expires_next.tv64 != KTIME_MAX)
 		tick_program_event(cpu_base->expires_next, 1);
 }
@@ -651,7 +623,7 @@ static void retrigger_next_event(void *arg)
 	base->clock_base[CLOCK_REALTIME].offset =
 		timespec_to_ktime(realtime_offset);
 
-	hrtimer_force_reprogram(base);
+	hrtimer_force_reprogram(base, 0);
 	spin_unlock(&base->lock);
 }
 
@@ -754,8 +726,6 @@ static int hrtimer_switch_to_hres(void)
 	/* "Retrigger" the interrupt to get things going */
 	retrigger_next_event(NULL);
 	local_irq_restore(flags);
-	printk(KERN_DEBUG "Switched to high resolution mode on CPU %d\n",
-	       smp_processor_id());
 	return 1;
 }
 
@@ -764,7 +734,8 @@ static int hrtimer_switch_to_hres(void)
 static inline int hrtimer_hres_active(void) { return 0; }
 static inline int hrtimer_is_hres_enabled(void) { return 0; }
 static inline int hrtimer_switch_to_hres(void) { return 0; }
-static inline void hrtimer_force_reprogram(struct hrtimer_cpu_base *base) { }
+static inline void
+hrtimer_force_reprogram(struct hrtimer_cpu_base *base, int skip_equal) { }
 static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
 					    struct hrtimer_clock_base *base,
 					    int wakeup)
@@ -854,7 +825,7 @@ static int enqueue_hrtimer(struct hrtimer *timer,
 	struct hrtimer *entry;
 	int leftmost = 1;
 
-	debug_hrtimer_activate(timer);
+	debug_activate(timer);
 
 	/*
 	 * Find the right place in the rbtree:
@@ -907,19 +878,29 @@ static void __remove_hrtimer(struct hrtimer *timer,
 			     struct hrtimer_clock_base *base,
 			     unsigned long newstate, int reprogram)
 {
-	if (timer->state & HRTIMER_STATE_ENQUEUED) {
-		/*
-		 * Remove the timer from the rbtree and replace the
-		 * first entry pointer if necessary.
-		 */
-		if (base->first == &timer->node) {
-			base->first = rb_next(&timer->node);
-			/* Reprogram the clock event device. if enabled */
-			if (reprogram && hrtimer_hres_active())
-				hrtimer_force_reprogram(base->cpu_base);
+	if (!(timer->state & HRTIMER_STATE_ENQUEUED))
+		goto out;
+
+	/*
+	 * Remove the timer from the rbtree and replace the first
+	 * entry pointer if necessary.
+	 */
+	if (base->first == &timer->node) {
+		base->first = rb_next(&timer->node);
+#ifdef CONFIG_HIGH_RES_TIMERS
+		/* Reprogram the clock event device. if enabled */
+		if (reprogram && hrtimer_hres_active()) {
+			ktime_t expires;
+
+			expires = ktime_sub(hrtimer_get_expires(timer),
+					    base->offset);
+			if (base->cpu_base->expires_next.tv64 == expires.tv64)
+				hrtimer_force_reprogram(base->cpu_base, 1);
 		}
-		rb_erase(&timer->node, &base->active);
+#endif
 	}
+	rb_erase(&timer->node, &base->active);
+out:
 	timer->state = newstate;
 }
 
@@ -940,7 +921,7 @@ remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base)
 		 * reprogramming happens in the interrupt handler. This is a
 		 * rare case and less expensive than a smp call.
 		 */
-		debug_hrtimer_deactivate(timer);
+		debug_deactivate(timer);
 		timer_stats_hrtimer_clear_start_info(timer);
 		reprogram = base->cpu_base == &__get_cpu_var(hrtimer_bases);
 		__remove_hrtimer(timer, base, HRTIMER_STATE_INACTIVE,
@@ -1155,7 +1136,6 @@ static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
 		clock_id = CLOCK_MONOTONIC;
 
 	timer->base = &cpu_base->clock_base[clock_id];
-	INIT_LIST_HEAD(&timer->cb_entry);
 	hrtimer_init_timer_hres(timer);
 
 #ifdef CONFIG_TIMER_STATS
@@ -1174,7 +1154,7 @@ static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
 void hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
 		  enum hrtimer_mode mode)
 {
-	debug_hrtimer_init(timer);
+	debug_init(timer, clock_id, mode);
 	__hrtimer_init(timer, clock_id, mode);
 }
 EXPORT_SYMBOL_GPL(hrtimer_init);
@@ -1198,7 +1178,7 @@ int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp)
 }
 EXPORT_SYMBOL_GPL(hrtimer_get_res);
 
-static void __run_hrtimer(struct hrtimer *timer)
+static void __run_hrtimer(struct hrtimer *timer, ktime_t *now)
 {
 	struct hrtimer_clock_base *base = timer->base;
 	struct hrtimer_cpu_base *cpu_base = base->cpu_base;
@@ -1207,7 +1187,7 @@ static void __run_hrtimer(struct hrtimer *timer)
 
 	WARN_ON(!irqs_disabled());
 
-	debug_hrtimer_deactivate(timer);
+	debug_deactivate(timer);
 	__remove_hrtimer(timer, base, HRTIMER_STATE_CALLBACK, 0);
 	timer_stats_account_hrtimer(timer);
 	fn = timer->function;
@@ -1218,7 +1198,9 @@ static void __run_hrtimer(struct hrtimer *timer)
 	 * the timer base.
 	 */
 	spin_unlock(&cpu_base->lock);
+	trace_hrtimer_expire_entry(timer, now);
 	restart = fn(timer);
+	trace_hrtimer_expire_exit(timer);
 	spin_lock(&cpu_base->lock);
 
 	/*
@@ -1329,7 +1311,7 @@ void hrtimer_interrupt(struct clock_event_device *dev)
 				break;
 			}
 
-			__run_hrtimer(timer);
+			__run_hrtimer(timer, &basenow);
 		}
 		base++;
 	}
@@ -1451,7 +1433,7 @@ void hrtimer_run_queues(void)
 					hrtimer_get_expires_tv64(timer))
 				break;
 
-			__run_hrtimer(timer);
+			__run_hrtimer(timer, &base->softirq_time);
 		}
 		spin_unlock(&cpu_base->lock);
 	}
@@ -1628,7 +1610,7 @@ static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base,
 	while ((node = rb_first(&old_base->active))) {
 		timer = rb_entry(node, struct hrtimer, node);
 		BUG_ON(hrtimer_callback_running(timer));
-		debug_hrtimer_deactivate(timer);
+		debug_deactivate(timer);
 
 		/*
 		 * Mark it as STATE_MIGRATE not INACTIVE otherwise the
diff --git a/kernel/hung_task.c b/kernel/hung_task.c
index 022a4927b78..d4e84174740 100644
--- a/kernel/hung_task.c
+++ b/kernel/hung_task.c
@@ -171,12 +171,12 @@ static unsigned long timeout_jiffies(unsigned long timeout)
  * Process updating of timeout sysctl
  */
 int proc_dohung_task_timeout_secs(struct ctl_table *table, int write,
-				  struct file *filp, void __user *buffer,
+				  void __user *buffer,
 				  size_t *lenp, loff_t *ppos)
 {
 	int ret;
 
-	ret = proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos);
+	ret = proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
 
 	if (ret || !write)
 		goto out;
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index a81cf80554d..17c71bb565c 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -11,6 +11,7 @@
  */
 
 #include <linux/irq.h>
+#include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/random.h>
diff --git a/kernel/itimer.c b/kernel/itimer.c
index 58762f7077e..b03451ede52 100644
--- a/kernel/itimer.c
+++ b/kernel/itimer.c
@@ -12,6 +12,7 @@
 #include <linux/time.h>
 #include <linux/posix-timers.h>
 #include <linux/hrtimer.h>
+#include <trace/events/timer.h>
 
 #include <asm/uaccess.h>
 
@@ -41,10 +42,43 @@ static struct timeval itimer_get_remtime(struct hrtimer *timer)
 	return ktime_to_timeval(rem);
 }
 
+static void get_cpu_itimer(struct task_struct *tsk, unsigned int clock_id,
+			   struct itimerval *const value)
+{
+	cputime_t cval, cinterval;
+	struct cpu_itimer *it = &tsk->signal->it[clock_id];
+
+	spin_lock_irq(&tsk->sighand->siglock);
+
+	cval = it->expires;
+	cinterval = it->incr;
+	if (!cputime_eq(cval, cputime_zero)) {
+		struct task_cputime cputime;
+		cputime_t t;
+
+		thread_group_cputimer(tsk, &cputime);
+		if (clock_id == CPUCLOCK_PROF)
+			t = cputime_add(cputime.utime, cputime.stime);
+		else
+			/* CPUCLOCK_VIRT */
+			t = cputime.utime;
+
+		if (cputime_le(cval, t))
+			/* about to fire */
+			cval = cputime_one_jiffy;
+		else
+			cval = cputime_sub(cval, t);
+	}
+
+	spin_unlock_irq(&tsk->sighand->siglock);
+
+	cputime_to_timeval(cval, &value->it_value);
+	cputime_to_timeval(cinterval, &value->it_interval);
+}
+
 int do_getitimer(int which, struct itimerval *value)
 {
 	struct task_struct *tsk = current;
-	cputime_t cinterval, cval;
 
 	switch (which) {
 	case ITIMER_REAL:
@@ -55,44 +89,10 @@ int do_getitimer(int which, struct itimerval *value)
 		spin_unlock_irq(&tsk->sighand->siglock);
 		break;
 	case ITIMER_VIRTUAL:
-		spin_lock_irq(&tsk->sighand->siglock);
-		cval = tsk->signal->it_virt_expires;
-		cinterval = tsk->signal->it_virt_incr;
-		if (!cputime_eq(cval, cputime_zero)) {
-			struct task_cputime cputime;
-			cputime_t utime;
-
-			thread_group_cputimer(tsk, &cputime);
-			utime = cputime.utime;
-			if (cputime_le(cval, utime)) { /* about to fire */
-				cval = jiffies_to_cputime(1);
-			} else {
-				cval = cputime_sub(cval, utime);
-			}
-		}
-		spin_unlock_irq(&tsk->sighand->siglock);
-		cputime_to_timeval(cval, &value->it_value);
-		cputime_to_timeval(cinterval, &value->it_interval);
+		get_cpu_itimer(tsk, CPUCLOCK_VIRT, value);
 		break;
 	case ITIMER_PROF:
-		spin_lock_irq(&tsk->sighand->siglock);
-		cval = tsk->signal->it_prof_expires;
-		cinterval = tsk->signal->it_prof_incr;
-		if (!cputime_eq(cval, cputime_zero)) {
-			struct task_cputime times;
-			cputime_t ptime;
-
-			thread_group_cputimer(tsk, &times);
-			ptime = cputime_add(times.utime, times.stime);
-			if (cputime_le(cval, ptime)) { /* about to fire */
-				cval = jiffies_to_cputime(1);
-			} else {
-				cval = cputime_sub(cval, ptime);
-			}
-		}
-		spin_unlock_irq(&tsk->sighand->siglock);
-		cputime_to_timeval(cval, &value->it_value);
-		cputime_to_timeval(cinterval, &value->it_interval);
+		get_cpu_itimer(tsk, CPUCLOCK_PROF, value);
 		break;
 	default:
 		return(-EINVAL);
@@ -123,11 +123,62 @@ enum hrtimer_restart it_real_fn(struct hrtimer *timer)
 	struct signal_struct *sig =
 		container_of(timer, struct signal_struct, real_timer);
 
+	trace_itimer_expire(ITIMER_REAL, sig->leader_pid, 0);
 	kill_pid_info(SIGALRM, SEND_SIG_PRIV, sig->leader_pid);
 
 	return HRTIMER_NORESTART;
 }
 
+static inline u32 cputime_sub_ns(cputime_t ct, s64 real_ns)
+{
+	struct timespec ts;
+	s64 cpu_ns;
+
+	cputime_to_timespec(ct, &ts);
+	cpu_ns = timespec_to_ns(&ts);
+
+	return (cpu_ns <= real_ns) ? 0 : cpu_ns - real_ns;
+}
+
+static void set_cpu_itimer(struct task_struct *tsk, unsigned int clock_id,
+			   const struct itimerval *const value,
+			   struct itimerval *const ovalue)
+{
+	cputime_t cval, nval, cinterval, ninterval;
+	s64 ns_ninterval, ns_nval;
+	struct cpu_itimer *it = &tsk->signal->it[clock_id];
+
+	nval = timeval_to_cputime(&value->it_value);
+	ns_nval = timeval_to_ns(&value->it_value);
+	ninterval = timeval_to_cputime(&value->it_interval);
+	ns_ninterval = timeval_to_ns(&value->it_interval);
+
+	it->incr_error = cputime_sub_ns(ninterval, ns_ninterval);
+	it->error = cputime_sub_ns(nval, ns_nval);
+
+	spin_lock_irq(&tsk->sighand->siglock);
+
+	cval = it->expires;
+	cinterval = it->incr;
+	if (!cputime_eq(cval, cputime_zero) ||
+	    !cputime_eq(nval, cputime_zero)) {
+		if (cputime_gt(nval, cputime_zero))
+			nval = cputime_add(nval, cputime_one_jiffy);
+		set_process_cpu_timer(tsk, clock_id, &nval, &cval);
+	}
+	it->expires = nval;
+	it->incr = ninterval;
+	trace_itimer_state(clock_id == CPUCLOCK_VIRT ?
+			   ITIMER_VIRTUAL : ITIMER_PROF, value, nval);
+
+	spin_unlock_irq(&tsk->sighand->siglock);
+
+	if (ovalue) {
+		cputime_to_timeval(cval, &ovalue->it_value);
+		cputime_to_timeval(cinterval, &ovalue->it_interval);
+	}
+}
+
 /*
  * Returns true if the timeval is in canonical form
  */
@@ -139,7 +190,6 @@ int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue)
 	struct task_struct *tsk = current;
 	struct hrtimer *timer;
 	ktime_t expires;
-	cputime_t cval, cinterval, nval, ninterval;
 
 	/*
 	 * Validate the timevals in value.
@@ -171,51 +221,14 @@ again:
 		} else
 			tsk->signal->it_real_incr.tv64 = 0;
 
+		trace_itimer_state(ITIMER_REAL, value, 0);
 		spin_unlock_irq(&tsk->sighand->siglock);
 		break;
 	case ITIMER_VIRTUAL:
-		nval = timeval_to_cputime(&value->it_value);
-		ninterval = timeval_to_cputime(&value->it_interval);
-		spin_lock_irq(&tsk->sighand->siglock);
-		cval = tsk->signal->it_virt_expires;
-		cinterval = tsk->signal->it_virt_incr;
-		if (!cputime_eq(cval, cputime_zero) ||
-		    !cputime_eq(nval, cputime_zero)) {
-			if (cputime_gt(nval, cputime_zero))
-				nval = cputime_add(nval,
-						   jiffies_to_cputime(1));
-			set_process_cpu_timer(tsk, CPUCLOCK_VIRT,
-					      &nval, &cval);
-		}
-		tsk->signal->it_virt_expires = nval;
-		tsk->signal->it_virt_incr = ninterval;
-		spin_unlock_irq(&tsk->sighand->siglock);
-		if (ovalue) {
-			cputime_to_timeval(cval, &ovalue->it_value);
-			cputime_to_timeval(cinterval, &ovalue->it_interval);
-		}
+		set_cpu_itimer(tsk, CPUCLOCK_VIRT, value, ovalue);
 		break;
 	case ITIMER_PROF:
-		nval = timeval_to_cputime(&value->it_value);
-		ninterval = timeval_to_cputime(&value->it_interval);
-		spin_lock_irq(&tsk->sighand->siglock);
-		cval = tsk->signal->it_prof_expires;
-		cinterval = tsk->signal->it_prof_incr;
-		if (!cputime_eq(cval, cputime_zero) ||
-		    !cputime_eq(nval, cputime_zero)) {
-			if (cputime_gt(nval, cputime_zero))
-				nval = cputime_add(nval,
-						   jiffies_to_cputime(1));
-			set_process_cpu_timer(tsk, CPUCLOCK_PROF,
-					      &nval, &cval);
-		}
-		tsk->signal->it_prof_expires = nval;
-		tsk->signal->it_prof_incr = ninterval;
-		spin_unlock_irq(&tsk->sighand->siglock);
-		if (ovalue) {
-			cputime_to_timeval(cval, &ovalue->it_value);
-			cputime_to_timeval(cinterval, &ovalue->it_interval);
-		}
+		set_cpu_itimer(tsk, CPUCLOCK_PROF, value, ovalue);
 		break;
 	default:
 		return -EINVAL;
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index 3a29dbe7898..8b6b8b697c6 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -59,7 +59,8 @@ static inline int is_kernel_inittext(unsigned long addr)
 
 static inline int is_kernel_text(unsigned long addr)
 {
-	if (addr >= (unsigned long)_stext && addr <= (unsigned long)_etext)
+	if ((addr >= (unsigned long)_stext && addr <= (unsigned long)_etext) ||
+	    arch_is_kernel_text(addr))
 		return 1;
 	return in_gate_area_no_task(addr);
 }
diff --git a/kernel/kfifo.c b/kernel/kfifo.c
index 26539e3228e..3765ff3c1bb 100644
--- a/kernel/kfifo.c
+++ b/kernel/kfifo.c
@@ -117,7 +117,7 @@ EXPORT_SYMBOL(kfifo_free);
  * writer, you don't need extra locking to use these functions.
  */
 unsigned int __kfifo_put(struct kfifo *fifo,
-			 unsigned char *buffer, unsigned int len)
+			const unsigned char *buffer, unsigned int len)
 {
 	unsigned int l;
 
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index ef177d653b2..5240d75f4c6 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1321,7 +1321,7 @@ static int __kprobes show_kprobe_addr(struct seq_file *pi, void *v)
 	return 0;
 }
 
-static struct seq_operations kprobes_seq_ops = {
+static const struct seq_operations kprobes_seq_ops = {
 	.start = kprobe_seq_start,
 	.next  = kprobe_seq_next,
 	.stop  = kprobe_seq_stop,
@@ -1333,7 +1333,7 @@ static int __kprobes kprobes_open(struct inode *inode, struct file *filp)
 	return seq_open(filp, &kprobes_seq_ops);
 }
 
-static struct file_operations debugfs_kprobes_operations = {
+static const struct file_operations debugfs_kprobes_operations = {
 	.open           = kprobes_open,
 	.read           = seq_read,
 	.llseek         = seq_lseek,
@@ -1515,7 +1515,7 @@ static ssize_t write_enabled_file_bool(struct file *file,
 	return count;
 }
 
-static struct file_operations fops_kp = {
+static const struct file_operations fops_kp = {
 	.read =         read_enabled_file_bool,
 	.write =        write_enabled_file_bool,
 };
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index f74d2d7aa60..9af56723c09 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -142,6 +142,11 @@ static inline struct lock_class *hlock_class(struct held_lock *hlock)
 #ifdef CONFIG_LOCK_STAT
 static DEFINE_PER_CPU(struct lock_class_stats[MAX_LOCKDEP_KEYS], lock_stats);
 
+static inline u64 lockstat_clock(void)
+{
+	return cpu_clock(smp_processor_id());
+}
+
 static int lock_point(unsigned long points[], unsigned long ip)
 {
 	int i;
@@ -158,7 +163,7 @@ static int lock_point(unsigned long points[], unsigned long ip)
 	return i;
 }
 
-static void lock_time_inc(struct lock_time *lt, s64 time)
+static void lock_time_inc(struct lock_time *lt, u64 time)
 {
 	if (time > lt->max)
 		lt->max = time;
@@ -234,12 +239,12 @@ static void put_lock_stats(struct lock_class_stats *stats)
 static void lock_release_holdtime(struct held_lock *hlock)
 {
 	struct lock_class_stats *stats;
-	s64 holdtime;
+	u64 holdtime;
 
 	if (!lock_stat)
 		return;
 
-	holdtime = sched_clock() - hlock->holdtime_stamp;
+	holdtime = lockstat_clock() - hlock->holdtime_stamp;
 
 	stats = get_lock_stats(hlock_class(hlock));
 	if (hlock->read)
@@ -578,6 +583,9 @@ static int static_obj(void *obj)
 	if ((addr >= start) && (addr < end))
 		return 1;
 
+	if (arch_is_kernel_data(addr))
+		return 1;
+
 #ifdef CONFIG_SMP
 	/*
 	 * percpu var?
@@ -2789,7 +2797,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 	hlock->references = references;
 #ifdef CONFIG_LOCK_STAT
 	hlock->waittime_stamp = 0;
-	hlock->holdtime_stamp = sched_clock();
+	hlock->holdtime_stamp = lockstat_clock();
 #endif
 
 	if (check == 2 && !mark_irqflags(curr, hlock))
@@ -3319,7 +3327,7 @@ found_it:
 	if (hlock->instance != lock)
 		return;
 
-	hlock->waittime_stamp = sched_clock();
+	hlock->waittime_stamp = lockstat_clock();
 
 	contention_point = lock_point(hlock_class(hlock)->contention_point, ip);
 	contending_point = lock_point(hlock_class(hlock)->contending_point,
@@ -3342,8 +3350,7 @@ __lock_acquired(struct lockdep_map *lock, unsigned long ip)
 	struct held_lock *hlock, *prev_hlock;
 	struct lock_class_stats *stats;
 	unsigned int depth;
-	u64 now;
-	s64 waittime = 0;
+	u64 now, waittime = 0;
 	int i, cpu;
 
 	depth = curr->lockdep_depth;
@@ -3371,7 +3378,7 @@ found_it:
 
 	cpu = smp_processor_id();
 	if (hlock->waittime_stamp) {
-		now = sched_clock();
+		now = lockstat_clock();
 		waittime = now - hlock->waittime_stamp;
 		hlock->holdtime_stamp = now;
 	}
diff --git a/kernel/lockdep_proc.c b/kernel/lockdep_proc.c
index d4b3dbc79fd..d4aba4f3584 100644
--- a/kernel/lockdep_proc.c
+++ b/kernel/lockdep_proc.c
@@ -594,7 +594,7 @@ static int ls_show(struct seq_file *m, void *v)
 	return 0;
 }
 
-static struct seq_operations lockstat_ops = {
+static const struct seq_operations lockstat_ops = {
 	.start	= ls_start,
 	.next	= ls_next,
 	.stop	= ls_stop,
diff --git a/kernel/marker.c b/kernel/marker.c
deleted file mode 100644
index ea54f264786..00000000000
--- a/kernel/marker.c
+++ /dev/null
@@ -1,930 +0,0 @@
-/*
- * Copyright (C) 2007 Mathieu Desnoyers
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
- */
-#include <linux/module.h>
-#include <linux/mutex.h>
-#include <linux/types.h>
-#include <linux/jhash.h>
-#include <linux/list.h>
-#include <linux/rcupdate.h>
-#include <linux/marker.h>
-#include <linux/err.h>
-#include <linux/slab.h>
-
-extern struct marker __start___markers[];
-extern struct marker __stop___markers[];
-
-/* Set to 1 to enable marker debug output */
-static const int marker_debug;
-
-/*
- * markers_mutex nests inside module_mutex. Markers mutex protects the builtin
- * and module markers and the hash table.
- */
-static DEFINE_MUTEX(markers_mutex);
-
-/*
- * Marker hash table, containing the active markers.
- * Protected by module_mutex.
- */
-#define MARKER_HASH_BITS 6
-#define MARKER_TABLE_SIZE (1 << MARKER_HASH_BITS)
-static struct hlist_head marker_table[MARKER_TABLE_SIZE];
-
-/*
- * Note about RCU :
- * It is used to make sure every handler has finished using its private data
- * between two consecutive operation (add or remove) on a given marker.  It is
- * also used to delay the free of multiple probes array until a quiescent state
- * is reached.
- * marker entries modifications are protected by the markers_mutex.
- */
-struct marker_entry {
-	struct hlist_node hlist;
-	char *format;
-			/* Probe wrapper */
-	void (*call)(const struct marker *mdata, void *call_private, ...);
-	struct marker_probe_closure single;
-	struct marker_probe_closure *multi;
-	int refcount;	/* Number of times armed. 0 if disarmed. */
-	struct rcu_head rcu;
-	void *oldptr;
-	int rcu_pending;
-	unsigned char ptype:1;
-	unsigned char format_allocated:1;
-	char name[0];	/* Contains name'\0'format'\0' */
-};
-
-/**
- * __mark_empty_function - Empty probe callback
- * @probe_private: probe private data
- * @call_private: call site private data
- * @fmt: format string
- * @...: variable argument list
- *
- * Empty callback provided as a probe to the markers. By providing this to a
- * disabled marker, we make sure the  execution flow is always valid even
- * though the function pointer change and the marker enabling are two distinct
- * operations that modifies the execution flow of preemptible code.
- */
-notrace void __mark_empty_function(void *probe_private, void *call_private,
-	const char *fmt, va_list *args)
-{
-}
-EXPORT_SYMBOL_GPL(__mark_empty_function);
-
-/*
- * marker_probe_cb Callback that prepares the variable argument list for probes.
- * @mdata: pointer of type struct marker
- * @call_private: caller site private data
- * @...:  Variable argument list.
- *
- * Since we do not use "typical" pointer based RCU in the 1 argument case, we
- * need to put a full smp_rmb() in this branch. This is why we do not use
- * rcu_dereference() for the pointer read.
- */
-notrace void marker_probe_cb(const struct marker *mdata,
-		void *call_private, ...)
-{
-	va_list args;
-	char ptype;
-
-	/*
-	 * rcu_read_lock_sched does two things : disabling preemption to make
-	 * sure the teardown of the callbacks can be done correctly when they
-	 * are in modules and they insure RCU read coherency.
-	 */
-	rcu_read_lock_sched_notrace();
-	ptype = mdata->ptype;
-	if (likely(!ptype)) {
-		marker_probe_func *func;
-		/* Must read the ptype before ptr. They are not data dependant,
-		 * so we put an explicit smp_rmb() here. */
-		smp_rmb();
-		func = mdata->single.func;
-		/* Must read the ptr before private data. They are not data
-		 * dependant, so we put an explicit smp_rmb() here. */
-		smp_rmb();
-		va_start(args, call_private);
-		func(mdata->single.probe_private, call_private, mdata->format,
-			&args);
-		va_end(args);
-	} else {
-		struct marker_probe_closure *multi;
-		int i;
-		/*
-		 * Read mdata->ptype before mdata->multi.
-		 */
-		smp_rmb();
-		multi = mdata->multi;
-		/*
-		 * multi points to an array, therefore accessing the array
-		 * depends on reading multi. However, even in this case,
-		 * we must insure that the pointer is read _before_ the array
-		 * data. Same as rcu_dereference, but we need a full smp_rmb()
-		 * in the fast path, so put the explicit barrier here.
-		 */
-		smp_read_barrier_depends();
-		for (i = 0; multi[i].func; i++) {
-			va_start(args, call_private);
-			multi[i].func(multi[i].probe_private, call_private,
-				mdata->format, &args);
-			va_end(args);
-		}
-	}
-	rcu_read_unlock_sched_notrace();
-}
-EXPORT_SYMBOL_GPL(marker_probe_cb);
-
-/*
- * marker_probe_cb Callback that does not prepare the variable argument list.
- * @mdata: pointer of type struct marker
- * @call_private: caller site private data
- * @...:  Variable argument list.
- *
- * Should be connected to markers "MARK_NOARGS".
- */
-static notrace void marker_probe_cb_noarg(const struct marker *mdata,
-		void *call_private, ...)
-{
-	va_list args;	/* not initialized */
-	char ptype;
-
-	rcu_read_lock_sched_notrace();
-	ptype = mdata->ptype;
-	if (likely(!ptype)) {
-		marker_probe_func *func;
-		/* Must read the ptype before ptr. They are not data dependant,
-		 * so we put an explicit smp_rmb() here. */
-		smp_rmb();
-		func = mdata->single.func;
-		/* Must read the ptr before private data. They are not data
-		 * dependant, so we put an explicit smp_rmb() here. */
-		smp_rmb();
-		func(mdata->single.probe_private, call_private, mdata->format,
-			&args);
-	} else {
-		struct marker_probe_closure *multi;
-		int i;
-		/*
-		 * Read mdata->ptype before mdata->multi.
-		 */
-		smp_rmb();
-		multi = mdata->multi;
-		/*
-		 * multi points to an array, therefore accessing the array
-		 * depends on reading multi. However, even in this case,
-		 * we must insure that the pointer is read _before_ the array
-		 * data. Same as rcu_dereference, but we need a full smp_rmb()
-		 * in the fast path, so put the explicit barrier here.
-		 */
-		smp_read_barrier_depends();
-		for (i = 0; multi[i].func; i++)
-			multi[i].func(multi[i].probe_private, call_private,
-				mdata->format, &args);
-	}
-	rcu_read_unlock_sched_notrace();
-}
-
-static void free_old_closure(struct rcu_head *head)
-{
-	struct marker_entry *entry = container_of(head,
-		struct marker_entry, rcu);
-	kfree(entry->oldptr);
-	/* Make sure we free the data before setting the pending flag to 0 */
-	smp_wmb();
-	entry->rcu_pending = 0;
-}
-
-static void debug_print_probes(struct marker_entry *entry)
-{
-	int i;
-
-	if (!marker_debug)
-		return;
-
-	if (!entry->ptype) {
-		printk(KERN_DEBUG "Single probe : %p %p\n",
-			entry->single.func,
-			entry->single.probe_private);
-	} else {
-		for (i = 0; entry->multi[i].func; i++)
-			printk(KERN_DEBUG "Multi probe %d : %p %p\n", i,
-				entry->multi[i].func,
-				entry->multi[i].probe_private);
-	}
-}
-
-static struct marker_probe_closure *
-marker_entry_add_probe(struct marker_entry *entry,
-		marker_probe_func *probe, void *probe_private)
-{
-	int nr_probes = 0;
-	struct marker_probe_closure *old, *new;
-
-	WARN_ON(!probe);
-
-	debug_print_probes(entry);
-	old = entry->multi;
-	if (!entry->ptype) {
-		if (entry->single.func == probe &&
-				entry->single.probe_private == probe_private)
-			return ERR_PTR(-EBUSY);
-		if (entry->single.func == __mark_empty_function) {
-			/* 0 -> 1 probes */
-			entry->single.func = probe;
-			entry->single.probe_private = probe_private;
-			entry->refcount = 1;
-			entry->ptype = 0;
-			debug_print_probes(entry);
-			return NULL;
-		} else {
-			/* 1 -> 2 probes */
-			nr_probes = 1;
-			old = NULL;
-		}
-	} else {
-		/* (N -> N+1), (N != 0, 1) probes */
-		for (nr_probes = 0; old[nr_probes].func; nr_probes++)
-			if (old[nr_probes].func == probe
-					&& old[nr_probes].probe_private
-						== probe_private)
-				return ERR_PTR(-EBUSY);
-	}
-	/* + 2 : one for new probe, one for NULL func */
-	new = kzalloc((nr_probes + 2) * sizeof(struct marker_probe_closure),
-			GFP_KERNEL);
-	if (new == NULL)
-		return ERR_PTR(-ENOMEM);
-	if (!old)
-		new[0] = entry->single;
-	else
-		memcpy(new, old,
-			nr_probes * sizeof(struct marker_probe_closure));
-	new[nr_probes].func = probe;
-	new[nr_probes].probe_private = probe_private;
-	entry->refcount = nr_probes + 1;
-	entry->multi = new;
-	entry->ptype = 1;
-	debug_print_probes(entry);
-	return old;
-}
-
-static struct marker_probe_closure *
-marker_entry_remove_probe(struct marker_entry *entry,
-		marker_probe_func *probe, void *probe_private)
-{
-	int nr_probes = 0, nr_del = 0, i;
-	struct marker_probe_closure *old, *new;
-
-	old = entry->multi;
-
-	debug_print_probes(entry);
-	if (!entry->ptype) {
-		/* 0 -> N is an error */
-		WARN_ON(entry->single.func == __mark_empty_function);
-		/* 1 -> 0 probes */
-		WARN_ON(probe && entry->single.func != probe);
-		WARN_ON(entry->single.probe_private != probe_private);
-		entry->single.func = __mark_empty_function;
-		entry->refcount = 0;
-		entry->ptype = 0;
-		debug_print_probes(entry);
-		return NULL;
-	} else {
-		/* (N -> M), (N > 1, M >= 0) probes */
-		for (nr_probes = 0; old[nr_probes].func; nr_probes++) {
-			if ((!probe || old[nr_probes].func == probe)
-					&& old[nr_probes].probe_private
-						== probe_private)
-				nr_del++;
-		}
-	}
-
-	if (nr_probes - nr_del == 0) {
-		/* N -> 0, (N > 1) */
-		entry->single.func = __mark_empty_function;
-		entry->refcount = 0;
-		entry->ptype = 0;
-	} else if (nr_probes - nr_del == 1) {
-		/* N -> 1, (N > 1) */
-		for (i = 0; old[i].func; i++)
-			if ((probe && old[i].func != probe) ||
-					old[i].probe_private != probe_private)
-				entry->single = old[i];
-		entry->refcount = 1;
-		entry->ptype = 0;
-	} else {
-		int j = 0;
-		/* N -> M, (N > 1, M > 1) */
-		/* + 1 for NULL */
-		new = kzalloc((nr_probes - nr_del + 1)
-			* sizeof(struct marker_probe_closure), GFP_KERNEL);
-		if (new == NULL)
-			return ERR_PTR(-ENOMEM);
-		for (i = 0; old[i].func; i++)
-			if ((probe && old[i].func != probe) ||
-					old[i].probe_private != probe_private)
-				new[j++] = old[i];
-		entry->refcount = nr_probes - nr_del;
-		entry->ptype = 1;
-		entry->multi = new;
-	}
-	debug_print_probes(entry);
-	return old;
-}
-
-/*
- * Get marker if the marker is present in the marker hash table.
- * Must be called with markers_mutex held.
- * Returns NULL if not present.
- */
-static struct marker_entry *get_marker(const char *name)
-{
-	struct hlist_head *head;
-	struct hlist_node *node;
-	struct marker_entry *e;
-	u32 hash = jhash(name, strlen(name), 0);
-
-	head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)];
-	hlist_for_each_entry(e, node, head, hlist) {
-		if (!strcmp(name, e->name))
-			return e;
-	}
-	return NULL;
-}
-
-/*
- * Add the marker to the marker hash table. Must be called with markers_mutex
- * held.
- */
-static struct marker_entry *add_marker(const char *name, const char *format)
-{
-	struct hlist_head *head;
-	struct hlist_node *node;
-	struct marker_entry *e;
-	size_t name_len = strlen(name) + 1;
-	size_t format_len = 0;
-	u32 hash = jhash(name, name_len-1, 0);
-
-	if (format)
-		format_len = strlen(format) + 1;
-	head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)];
-	hlist_for_each_entry(e, node, head, hlist) {
-		if (!strcmp(name, e->name)) {
-			printk(KERN_NOTICE
-				"Marker %s busy\n", name);
-			return ERR_PTR(-EBUSY);	/* Already there */
-		}
-	}
-	/*
-	 * Using kmalloc here to allocate a variable length element. Could
-	 * cause some memory fragmentation if overused.
-	 */
-	e = kmalloc(sizeof(struct marker_entry) + name_len + format_len,
-			GFP_KERNEL);
-	if (!e)
-		return ERR_PTR(-ENOMEM);
-	memcpy(&e->name[0], name, name_len);
-	if (format) {
-		e->format = &e->name[name_len];
-		memcpy(e->format, format, format_len);
-		if (strcmp(e->format, MARK_NOARGS) == 0)
-			e->call = marker_probe_cb_noarg;
-		else
-			e->call = marker_probe_cb;
-		trace_mark(core_marker_format, "name %s format %s",
-				e->name, e->format);
-	} else {
-		e->format = NULL;
-		e->call = marker_probe_cb;
-	}
-	e->single.func = __mark_empty_function;
-	e->single.probe_private = NULL;
-	e->multi = NULL;
-	e->ptype = 0;
-	e->format_allocated = 0;
-	e->refcount = 0;
-	e->rcu_pending = 0;
-	hlist_add_head(&e->hlist, head);
-	return e;
-}
-
-/*
- * Remove the marker from the marker hash table. Must be called with mutex_lock
- * held.
- */
-static int remove_marker(const char *name)
-{
-	struct hlist_head *head;
-	struct hlist_node *node;
-	struct marker_entry *e;
-	int found = 0;
-	size_t len = strlen(name) + 1;
-	u32 hash = jhash(name, len-1, 0);
-
-	head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)];
-	hlist_for_each_entry(e, node, head, hlist) {
-		if (!strcmp(name, e->name)) {
-			found = 1;
-			break;
-		}
-	}
-	if (!found)
-		return -ENOENT;
-	if (e->single.func != __mark_empty_function)
-		return -EBUSY;
-	hlist_del(&e->hlist);
-	if (e->format_allocated)
-		kfree(e->format);
-	/* Make sure the call_rcu has been executed */
-	if (e->rcu_pending)
-		rcu_barrier_sched();
-	kfree(e);
-	return 0;
-}
-
-/*
- * Set the mark_entry format to the format found in the element.
- */
-static int marker_set_format(struct marker_entry *entry, const char *format)
-{
-	entry->format = kstrdup(format, GFP_KERNEL);
-	if (!entry->format)
-		return -ENOMEM;
-	entry->format_allocated = 1;
-
-	trace_mark(core_marker_format, "name %s format %s",
-			entry->name, entry->format);
-	return 0;
-}
-
-/*
- * Sets the probe callback corresponding to one marker.
- */
-static int set_marker(struct marker_entry *entry, struct marker *elem,
-		int active)
-{
-	int ret = 0;
-	WARN_ON(strcmp(entry->name, elem->name) != 0);
-
-	if (entry->format) {
-		if (strcmp(entry->format, elem->format) != 0) {
-			printk(KERN_NOTICE
-				"Format mismatch for probe %s "
-				"(%s), marker (%s)\n",
-				entry->name,
-				entry->format,
-				elem->format);
-			return -EPERM;
-		}
-	} else {
-		ret = marker_set_format(entry, elem->format);
-		if (ret)
-			return ret;
-	}
-
-	/*
-	 * probe_cb setup (statically known) is done here. It is
-	 * asynchronous with the rest of execution, therefore we only
-	 * pass from a "safe" callback (with argument) to an "unsafe"
-	 * callback (does not set arguments).
-	 */
-	elem->call = entry->call;
-	/*
-	 * Sanity check :
-	 * We only update the single probe private data when the ptr is
-	 * set to a _non_ single probe! (0 -> 1 and N -> 1, N != 1)
-	 */
-	WARN_ON(elem->single.func != __mark_empty_function
-		&& elem->single.probe_private != entry->single.probe_private
-		&& !elem->ptype);
-	elem->single.probe_private = entry->single.probe_private;
-	/*
-	 * Make sure the private data is valid when we update the
-	 * single probe ptr.
-	 */
-	smp_wmb();
-	elem->single.func = entry->single.func;
-	/*
-	 * We also make sure that the new probe callbacks array is consistent
-	 * before setting a pointer to it.
-	 */
-	rcu_assign_pointer(elem->multi, entry->multi);
-	/*
-	 * Update the function or multi probe array pointer before setting the
-	 * ptype.
-	 */
-	smp_wmb();
-	elem->ptype = entry->ptype;
-
-	if (elem->tp_name && (active ^ elem->state)) {
-		WARN_ON(!elem->tp_cb);
-		/*
-		 * It is ok to directly call the probe registration because type
-		 * checking has been done in the __trace_mark_tp() macro.
-		 */
-
-		if (active) {
-			/*
-			 * try_module_get should always succeed because we hold
-			 * lock_module() to get the tp_cb address.
-			 */
-			ret = try_module_get(__module_text_address(
-				(unsigned long)elem->tp_cb));
-			BUG_ON(!ret);
-			ret = tracepoint_probe_register_noupdate(
-				elem->tp_name,
-				elem->tp_cb);
-		} else {
-			ret = tracepoint_probe_unregister_noupdate(
-				elem->tp_name,
-				elem->tp_cb);
-			/*
-			 * tracepoint_probe_update_all() must be called
-			 * before the module containing tp_cb is unloaded.
-			 */
-			module_put(__module_text_address(
-				(unsigned long)elem->tp_cb));
-		}
-	}
-	elem->state = active;
-
-	return ret;
-}
-
-/*
- * Disable a marker and its probe callback.
- * Note: only waiting an RCU period after setting elem->call to the empty
- * function insures that the original callback is not used anymore. This insured
- * by rcu_read_lock_sched around the call site.
- */
-static void disable_marker(struct marker *elem)
-{
-	int ret;
-
-	/* leave "call" as is. It is known statically. */
-	if (elem->tp_name && elem->state) {
-		WARN_ON(!elem->tp_cb);
-		/*
-		 * It is ok to directly call the probe registration because type
-		 * checking has been done in the __trace_mark_tp() macro.
-		 */
-		ret = tracepoint_probe_unregister_noupdate(elem->tp_name,
-			elem->tp_cb);
-		WARN_ON(ret);
-		/*
-		 * tracepoint_probe_update_all() must be called
-		 * before the module containing tp_cb is unloaded.
-		 */
-		module_put(__module_text_address((unsigned long)elem->tp_cb));
-	}
-	elem->state = 0;
-	elem->single.func = __mark_empty_function;
-	/* Update the function before setting the ptype */
-	smp_wmb();
-	elem->ptype = 0;	/* single probe */
-	/*
-	 * Leave the private data and id there, because removal is racy and
-	 * should be done only after an RCU period. These are never used until
-	 * the next initialization anyway.
-	 */
-}
-
-/**
- * marker_update_probe_range - Update a probe range
- * @begin: beginning of the range
- * @end: end of the range
- *
- * Updates the probe callback corresponding to a range of markers.
- */
-void marker_update_probe_range(struct marker *begin,
-	struct marker *end)
-{
-	struct marker *iter;
-	struct marker_entry *mark_entry;
-
-	mutex_lock(&markers_mutex);
-	for (iter = begin; iter < end; iter++) {
-		mark_entry = get_marker(iter->name);
-		if (mark_entry) {
-			set_marker(mark_entry, iter, !!mark_entry->refcount);
-			/*
-			 * ignore error, continue
-			 */
-		} else {
-			disable_marker(iter);
-		}
-	}
-	mutex_unlock(&markers_mutex);
-}
-
-/*
- * Update probes, removing the faulty probes.
- *
- * Internal callback only changed before the first probe is connected to it.
- * Single probe private data can only be changed on 0 -> 1 and 2 -> 1
- * transitions.  All other transitions will leave the old private data valid.
- * This makes the non-atomicity of the callback/private data updates valid.
- *
- * "special case" updates :
- * 0 -> 1 callback
- * 1 -> 0 callback
- * 1 -> 2 callbacks
- * 2 -> 1 callbacks
- * Other updates all behave the same, just like the 2 -> 3 or 3 -> 2 updates.
- * Site effect : marker_set_format may delete the marker entry (creating a
- * replacement).
- */
-static void marker_update_probes(void)
-{
-	/* Core kernel markers */
-	marker_update_probe_range(__start___markers, __stop___markers);
-	/* Markers in modules. */
-	module_update_markers();
-	tracepoint_probe_update_all();
-}
-
-/**
- * marker_probe_register -  Connect a probe to a marker
- * @name: marker name
- * @format: format string
- * @probe: probe handler
- * @probe_private: probe private data
- *
- * private data must be a valid allocated memory address, or NULL.
- * Returns 0 if ok, error value on error.
- * The probe address must at least be aligned on the architecture pointer size.
- */
-int marker_probe_register(const char *name, const char *format,
-			marker_probe_func *probe, void *probe_private)
-{
-	struct marker_entry *entry;
-	int ret = 0;
-	struct marker_probe_closure *old;
-
-	mutex_lock(&markers_mutex);
-	entry = get_marker(name);
-	if (!entry) {
-		entry = add_marker(name, format);
-		if (IS_ERR(entry))
-			ret = PTR_ERR(entry);
-	} else if (format) {
-		if (!entry->format)
-			ret = marker_set_format(entry, format);
-		else if (strcmp(entry->format, format))
-			ret = -EPERM;
-	}
-	if (ret)
-		goto end;
-
-	/*
-	 * If we detect that a call_rcu is pending for this marker,
-	 * make sure it's executed now.
-	 */
-	if (entry->rcu_pending)
-		rcu_barrier_sched();
-	old = marker_entry_add_probe(entry, probe, probe_private);
-	if (IS_ERR(old)) {
-		ret = PTR_ERR(old);
-		goto end;
-	}
-	mutex_unlock(&markers_mutex);
-	marker_update_probes();
-	mutex_lock(&markers_mutex);
-	entry = get_marker(name);
-	if (!entry)
-		goto end;
-	if (entry->rcu_pending)
-		rcu_barrier_sched();
-	entry->oldptr = old;
-	entry->rcu_pending = 1;
-	/* write rcu_pending before calling the RCU callback */
-	smp_wmb();
-	call_rcu_sched(&entry->rcu, free_old_closure);
-end:
-	mutex_unlock(&markers_mutex);
-	return ret;
-}
-EXPORT_SYMBOL_GPL(marker_probe_register);
-
-/**
- * marker_probe_unregister -  Disconnect a probe from a marker
- * @name: marker name
- * @probe: probe function pointer
- * @probe_private: probe private data
- *
- * Returns the private data given to marker_probe_register, or an ERR_PTR().
- * We do not need to call a synchronize_sched to make sure the probes have
- * finished running before doing a module unload, because the module unload
- * itself uses stop_machine(), which insures that every preempt disabled section
- * have finished.
- */
-int marker_probe_unregister(const char *name,
-	marker_probe_func *probe, void *probe_private)
-{
-	struct marker_entry *entry;
-	struct marker_probe_closure *old;
-	int ret = -ENOENT;
-
-	mutex_lock(&markers_mutex);
-	entry = get_marker(name);
-	if (!entry)
-		goto end;
-	if (entry->rcu_pending)
-		rcu_barrier_sched();
-	old = marker_entry_remove_probe(entry, probe, probe_private);
-	mutex_unlock(&markers_mutex);
-	marker_update_probes();
-	mutex_lock(&markers_mutex);
-	entry = get_marker(name);
-	if (!entry)
-		goto end;
-	if (entry->rcu_pending)
-		rcu_barrier_sched();
-	entry->oldptr = old;
-	entry->rcu_pending = 1;
-	/* write rcu_pending before calling the RCU callback */
-	smp_wmb();
-	call_rcu_sched(&entry->rcu, free_old_closure);
-	remove_marker(name);	/* Ignore busy error message */
-	ret = 0;
-end:
-	mutex_unlock(&markers_mutex);
-	return ret;
-}
-EXPORT_SYMBOL_GPL(marker_probe_unregister);
-
-static struct marker_entry *
-get_marker_from_private_data(marker_probe_func *probe, void *probe_private)
-{
-	struct marker_entry *entry;
-	unsigned int i;
-	struct hlist_head *head;
-	struct hlist_node *node;
-
-	for (i = 0; i < MARKER_TABLE_SIZE; i++) {
-		head = &marker_table[i];
-		hlist_for_each_entry(entry, node, head, hlist) {
-			if (!entry->ptype) {
-				if (entry->single.func == probe
-						&& entry->single.probe_private
-						== probe_private)
-					return entry;
-			} else {
-				struct marker_probe_closure *closure;
-				closure = entry->multi;
-				for (i = 0; closure[i].func; i++) {
-					if (closure[i].func == probe &&
-							closure[i].probe_private
-							== probe_private)
-						return entry;
-				}
-			}
-		}
-	}
-	return NULL;
-}
-
-/**
- * marker_probe_unregister_private_data -  Disconnect a probe from a marker
- * @probe: probe function
- * @probe_private: probe private data
- *
- * Unregister a probe by providing the registered private data.
- * Only removes the first marker found in hash table.
- * Return 0 on success or error value.
- * We do not need to call a synchronize_sched to make sure the probes have
- * finished running before doing a module unload, because the module unload
- * itself uses stop_machine(), which insures that every preempt disabled section
- * have finished.
- */
-int marker_probe_unregister_private_data(marker_probe_func *probe,
-		void *probe_private)
-{
-	struct marker_entry *entry;
-	int ret = 0;
-	struct marker_probe_closure *old;
-
-	mutex_lock(&markers_mutex);
-	entry = get_marker_from_private_data(probe, probe_private);
-	if (!entry) {
-		ret = -ENOENT;
-		goto end;
-	}
-	if (entry->rcu_pending)
-		rcu_barrier_sched();
-	old = marker_entry_remove_probe(entry, NULL, probe_private);
-	mutex_unlock(&markers_mutex);
-	marker_update_probes();
-	mutex_lock(&markers_mutex);
-	entry = get_marker_from_private_data(probe, probe_private);
-	if (!entry)
-		goto end;
-	if (entry->rcu_pending)
-		rcu_barrier_sched();
-	entry->oldptr = old;
-	entry->rcu_pending = 1;
-	/* write rcu_pending before calling the RCU callback */
-	smp_wmb();
-	call_rcu_sched(&entry->rcu, free_old_closure);
-	remove_marker(entry->name);	/* Ignore busy error message */
-end:
-	mutex_unlock(&markers_mutex);
-	return ret;
-}
-EXPORT_SYMBOL_GPL(marker_probe_unregister_private_data);
-
-/**
- * marker_get_private_data - Get a marker's probe private data
- * @name: marker name
- * @probe: probe to match
- * @num: get the nth matching probe's private data
- *
- * Returns the nth private data pointer (starting from 0) matching, or an
- * ERR_PTR.
- * Returns the private data pointer, or an ERR_PTR.
- * The private data pointer should _only_ be dereferenced if the caller is the
- * owner of the data, or its content could vanish. This is mostly used to
- * confirm that a caller is the owner of a registered probe.
- */
-void *marker_get_private_data(const char *name, marker_probe_func *probe,
-		int num)
-{
-	struct hlist_head *head;
-	struct hlist_node *node;
-	struct marker_entry *e;
-	size_t name_len = strlen(name) + 1;
-	u32 hash = jhash(name, name_len-1, 0);
-	int i;
-
-	head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)];
-	hlist_for_each_entry(e, node, head, hlist) {
-		if (!strcmp(name, e->name)) {
-			if (!e->ptype) {
-				if (num == 0 && e->single.func == probe)
-					return e->single.probe_private;
-			} else {
-				struct marker_probe_closure *closure;
-				int match = 0;
-				closure = e->multi;
-				for (i = 0; closure[i].func; i++) {
-					if (closure[i].func != probe)
-						continue;
-					if (match++ == num)
-						return closure[i].probe_private;
-				}
-			}
-			break;
-		}
-	}
-	return ERR_PTR(-ENOENT);
-}
-EXPORT_SYMBOL_GPL(marker_get_private_data);
-
-#ifdef CONFIG_MODULES
-
-int marker_module_notify(struct notifier_block *self,
-			 unsigned long val, void *data)
-{
-	struct module *mod = data;
-
-	switch (val) {
-	case MODULE_STATE_COMING:
-		marker_update_probe_range(mod->markers,
-			mod->markers + mod->num_markers);
-		break;
-	case MODULE_STATE_GOING:
-		marker_update_probe_range(mod->markers,
-			mod->markers + mod->num_markers);
-		break;
-	}
-	return 0;
-}
-
-struct notifier_block marker_module_nb = {
-	.notifier_call = marker_module_notify,
-	.priority = 0,
-};
-
-static int init_markers(void)
-{
-	return register_module_notifier(&marker_module_nb);
-}
-__initcall(init_markers);
-
-#endif /* CONFIG_MODULES */
diff --git a/kernel/module.c b/kernel/module.c
index 05ce49ced8f..8b7d8805819 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -47,6 +47,7 @@
 #include <linux/rculist.h>
 #include <asm/uaccess.h>
 #include <asm/cacheflush.h>
+#include <asm/mmu_context.h>
 #include <linux/license.h>
 #include <asm/sections.h>
 #include <linux/tracepoint.h>
@@ -1535,6 +1536,10 @@ static void free_module(struct module *mod)
 
 	/* Finally, free the core (containing the module structure) */
 	module_free(mod, mod->module_core);
+
+#ifdef CONFIG_MPU
+	update_protections(current->mm);
+#endif
 }
 
 void *__symbol_get(const char *symbol)
@@ -1792,6 +1797,17 @@ static void setup_modinfo(struct module *mod, Elf_Shdr *sechdrs,
 	}
 }
 
+static void free_modinfo(struct module *mod)
+{
+	struct module_attribute *attr;
+	int i;
+
+	for (i = 0; (attr = modinfo_attrs[i]); i++) {
+		if (attr->free)
+			attr->free(mod);
+	}
+}
+
 #ifdef CONFIG_KALLSYMS
 
 /* lookup symbol in given range of kernel_symbols */
@@ -1857,13 +1873,93 @@ static char elf_type(const Elf_Sym *sym,
 	return '?';
 }
 
+static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
+                           unsigned int shnum)
+{
+	const Elf_Shdr *sec;
+
+	if (src->st_shndx == SHN_UNDEF
+	    || src->st_shndx >= shnum
+	    || !src->st_name)
+		return false;
+
+	sec = sechdrs + src->st_shndx;
+	if (!(sec->sh_flags & SHF_ALLOC)
+#ifndef CONFIG_KALLSYMS_ALL
+	    || !(sec->sh_flags & SHF_EXECINSTR)
+#endif
+	    || (sec->sh_entsize & INIT_OFFSET_MASK))
+		return false;
+
+	return true;
+}
+
+static unsigned long layout_symtab(struct module *mod,
+				   Elf_Shdr *sechdrs,
+				   unsigned int symindex,
+				   unsigned int strindex,
+				   const Elf_Ehdr *hdr,
+				   const char *secstrings,
+				   unsigned long *pstroffs,
+				   unsigned long *strmap)
+{
+	unsigned long symoffs;
+	Elf_Shdr *symsect = sechdrs + symindex;
+	Elf_Shdr *strsect = sechdrs + strindex;
+	const Elf_Sym *src;
+	const char *strtab;
+	unsigned int i, nsrc, ndst;
+
+	/* Put symbol section at end of init part of module. */
+	symsect->sh_flags |= SHF_ALLOC;
+	symsect->sh_entsize = get_offset(mod, &mod->init_size, symsect,
+					 symindex) | INIT_OFFSET_MASK;
+	DEBUGP("\t%s\n", secstrings + symsect->sh_name);
+
+	src = (void *)hdr + symsect->sh_offset;
+	nsrc = symsect->sh_size / sizeof(*src);
+	strtab = (void *)hdr + strsect->sh_offset;
+	for (ndst = i = 1; i < nsrc; ++i, ++src)
+		if (is_core_symbol(src, sechdrs, hdr->e_shnum)) {
+			unsigned int j = src->st_name;
+
+			while(!__test_and_set_bit(j, strmap) && strtab[j])
+				++j;
+			++ndst;
+		}
+
+	/* Append room for core symbols at end of core part. */
+	symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
+	mod->core_size = symoffs + ndst * sizeof(Elf_Sym);
+
+	/* Put string table section at end of init part of module. */
+	strsect->sh_flags |= SHF_ALLOC;
+	strsect->sh_entsize = get_offset(mod, &mod->init_size, strsect,
+					 strindex) | INIT_OFFSET_MASK;
+	DEBUGP("\t%s\n", secstrings + strsect->sh_name);
+
+	/* Append room for core symbols' strings at end of core part. */
+	*pstroffs = mod->core_size;
+	__set_bit(0, strmap);
+	mod->core_size += bitmap_weight(strmap, strsect->sh_size);
+
+	return symoffs;
+}
+
 static void add_kallsyms(struct module *mod,
 			 Elf_Shdr *sechdrs,
+			 unsigned int shnum,
 			 unsigned int symindex,
 			 unsigned int strindex,
-			 const char *secstrings)
+			 unsigned long symoffs,
+			 unsigned long stroffs,
+			 const char *secstrings,
+			 unsigned long *strmap)
 {
-	unsigned int i;
+	unsigned int i, ndst;
+	const Elf_Sym *src;
+	Elf_Sym *dst;
+	char *s;
 
 	mod->symtab = (void *)sechdrs[symindex].sh_addr;
 	mod->num_symtab = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
@@ -1873,13 +1969,46 @@ static void add_kallsyms(struct module *mod,
 	for (i = 0; i < mod->num_symtab; i++)
 		mod->symtab[i].st_info
 			= elf_type(&mod->symtab[i], sechdrs, secstrings, mod);
+
+	mod->core_symtab = dst = mod->module_core + symoffs;
+	src = mod->symtab;
+	*dst = *src;
+	for (ndst = i = 1; i < mod->num_symtab; ++i, ++src) {
+		if (!is_core_symbol(src, sechdrs, shnum))
+			continue;
+		dst[ndst] = *src;
+		dst[ndst].st_name = bitmap_weight(strmap, dst[ndst].st_name);
+		++ndst;
+	}
+	mod->core_num_syms = ndst;
+
+	mod->core_strtab = s = mod->module_core + stroffs;
+	for (*s = 0, i = 1; i < sechdrs[strindex].sh_size; ++i)
+		if (test_bit(i, strmap))
+			*++s = mod->strtab[i];
 }
 #else
+static inline unsigned long layout_symtab(struct module *mod,
+					  Elf_Shdr *sechdrs,
+					  unsigned int symindex,
+					  unsigned int strindex,
+					  const Elf_Ehdr *hdr,
+					  const char *secstrings,
+					  unsigned long *pstroffs,
+					  unsigned long *strmap)
+{
+	return 0;
+}
+
 static inline void add_kallsyms(struct module *mod,
 				Elf_Shdr *sechdrs,
+				unsigned int shnum,
 				unsigned int symindex,
 				unsigned int strindex,
-				const char *secstrings)
+				unsigned long symoffs,
+				unsigned long stroffs,
+				const char *secstrings,
+				const unsigned long *strmap)
 {
 }
 #endif /* CONFIG_KALLSYMS */
@@ -1954,6 +2083,8 @@ static noinline struct module *load_module(void __user *umod,
 	struct module *mod;
 	long err = 0;
 	void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
+	unsigned long symoffs, stroffs, *strmap;
+
 	mm_segment_t old_fs;
 
 	DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n",
@@ -2035,11 +2166,6 @@ static noinline struct module *load_module(void __user *umod,
 	/* Don't keep modinfo and version sections. */
 	sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
 	sechdrs[versindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
-#ifdef CONFIG_KALLSYMS
-	/* Keep symbol and string tables for decoding later. */
-	sechdrs[symindex].sh_flags |= SHF_ALLOC;
-	sechdrs[strindex].sh_flags |= SHF_ALLOC;
-#endif
 
 	/* Check module struct version now, before we try to use module. */
 	if (!check_modstruct_version(sechdrs, versindex, mod)) {
@@ -2075,6 +2201,13 @@ static noinline struct module *load_module(void __user *umod,
 		goto free_hdr;
 	}
 
+	strmap = kzalloc(BITS_TO_LONGS(sechdrs[strindex].sh_size)
+			 * sizeof(long), GFP_KERNEL);
+	if (!strmap) {
+		err = -ENOMEM;
+		goto free_mod;
+	}
+
 	if (find_module(mod->name)) {
 		err = -EEXIST;
 		goto free_mod;
@@ -2104,6 +2237,8 @@ static noinline struct module *load_module(void __user *umod,
 	   this is done generically; there doesn't appear to be any
 	   special cases for the architectures. */
 	layout_sections(mod, hdr, sechdrs, secstrings);
+	symoffs = layout_symtab(mod, sechdrs, symindex, strindex, hdr,
+				secstrings, &stroffs, strmap);
 
 	/* Do the allocs. */
 	ptr = module_alloc_update_bounds(mod->core_size);
@@ -2237,10 +2372,6 @@ static noinline struct module *load_module(void __user *umod,
 				  sizeof(*mod->ctors), &mod->num_ctors);
 #endif
 
-#ifdef CONFIG_MARKERS
-	mod->markers = section_objs(hdr, sechdrs, secstrings, "__markers",
-				    sizeof(*mod->markers), &mod->num_markers);
-#endif
 #ifdef CONFIG_TRACEPOINTS
 	mod->tracepoints = section_objs(hdr, sechdrs, secstrings,
 					"__tracepoints",
@@ -2312,7 +2443,10 @@ static noinline struct module *load_module(void __user *umod,
 	percpu_modcopy(mod->percpu, (void *)sechdrs[pcpuindex].sh_addr,
 		       sechdrs[pcpuindex].sh_size);
 
-	add_kallsyms(mod, sechdrs, symindex, strindex, secstrings);
+	add_kallsyms(mod, sechdrs, hdr->e_shnum, symindex, strindex,
+		     symoffs, stroffs, secstrings, strmap);
+	kfree(strmap);
+	strmap = NULL;
 
 	if (!mod->taints) {
 		struct _ddebug *debug;
@@ -2384,13 +2518,14 @@ static noinline struct module *load_module(void __user *umod,
 	synchronize_sched();
 	module_arch_cleanup(mod);
  cleanup:
+	free_modinfo(mod);
 	kobject_del(&mod->mkobj.kobj);
 	kobject_put(&mod->mkobj.kobj);
  free_unload:
 	module_unload_free(mod);
 #if defined(CONFIG_MODULE_UNLOAD) && defined(CONFIG_SMP)
- free_init:
 	percpu_modfree(mod->refptr);
+ free_init:
 #endif
 	module_free(mod, mod->module_init);
  free_core:
@@ -2401,6 +2536,7 @@ static noinline struct module *load_module(void __user *umod,
 		percpu_modfree(percpu);
  free_mod:
 	kfree(args);
+	kfree(strmap);
  free_hdr:
 	vfree(hdr);
 	return ERR_PTR(err);
@@ -2490,6 +2626,11 @@ SYSCALL_DEFINE3(init_module, void __user *, umod,
 	/* Drop initial reference. */
 	module_put(mod);
 	trim_init_extable(mod);
+#ifdef CONFIG_KALLSYMS
+	mod->num_symtab = mod->core_num_syms;
+	mod->symtab = mod->core_symtab;
+	mod->strtab = mod->core_strtab;
+#endif
 	module_free(mod, mod->module_init);
 	mod->module_init = NULL;
 	mod->init_size = 0;
@@ -2951,27 +3092,12 @@ void module_layout(struct module *mod,
 		   struct modversion_info *ver,
 		   struct kernel_param *kp,
 		   struct kernel_symbol *ks,
-		   struct marker *marker,
 		   struct tracepoint *tp)
 {
 }
 EXPORT_SYMBOL(module_layout);
 #endif
 
-#ifdef CONFIG_MARKERS
-void module_update_markers(void)
-{
-	struct module *mod;
-
-	mutex_lock(&module_mutex);
-	list_for_each_entry(mod, &modules, list)
-		if (!mod->taints)
-			marker_update_probe_range(mod->markers,
-				mod->markers + mod->num_markers);
-	mutex_unlock(&module_mutex);
-}
-#endif
-
 #ifdef CONFIG_TRACEPOINTS
 void module_update_tracepoints(void)
 {
diff --git a/kernel/mutex-debug.c b/kernel/mutex-debug.c
index 50d022e5a56..ec815a960b5 100644
--- a/kernel/mutex-debug.c
+++ b/kernel/mutex-debug.c
@@ -16,6 +16,7 @@
 #include <linux/delay.h>
 #include <linux/module.h>
 #include <linux/poison.h>
+#include <linux/sched.h>
 #include <linux/spinlock.h>
 #include <linux/kallsyms.h>
 #include <linux/interrupt.h>
diff --git a/kernel/ns_cgroup.c b/kernel/ns_cgroup.c
index 5aa854f9e5a..2a5dfec8efe 100644
--- a/kernel/ns_cgroup.c
+++ b/kernel/ns_cgroup.c
@@ -42,8 +42,8 @@ int ns_cgroup_clone(struct task_struct *task, struct pid *pid)
  *       (hence either you are in the same cgroup as task, or in an
  *        ancestor cgroup thereof)
  */
-static int ns_can_attach(struct cgroup_subsys *ss,
-		struct cgroup *new_cgroup, struct task_struct *task)
+static int ns_can_attach(struct cgroup_subsys *ss, struct cgroup *new_cgroup,
+			 struct task_struct *task, bool threadgroup)
 {
 	if (current != task) {
 		if (!capable(CAP_SYS_ADMIN))
@@ -56,6 +56,18 @@ static int ns_can_attach(struct cgroup_subsys *ss,
 	if (!cgroup_is_descendant(new_cgroup, task))
 		return -EPERM;
 
+	if (threadgroup) {
+		struct task_struct *c;
+		rcu_read_lock();
+		list_for_each_entry_rcu(c, &task->thread_group, thread_group) {
+			if (!cgroup_is_descendant(new_cgroup, c)) {
+				rcu_read_unlock();
+				return -EPERM;
+			}
+		}
+		rcu_read_unlock();
+	}
+
 	return 0;
 }
 
diff --git a/kernel/panic.c b/kernel/panic.c
index 512ab73b0ca..96b45d0b4ba 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -90,6 +90,8 @@ NORET_TYPE void panic(const char * fmt, ...)
 
 	atomic_notifier_call_chain(&panic_notifier_list, 0, buf);
 
+	bust_spinlocks(0);
+
 	if (!panic_blink)
 		panic_blink = no_blink;
 
@@ -136,7 +138,6 @@ NORET_TYPE void panic(const char * fmt, ...)
 		mdelay(1);
 		i++;
 	}
-	bust_spinlocks(0);
 }
 
 EXPORT_SYMBOL(panic);
@@ -177,7 +178,7 @@ static const struct tnt tnts[] = {
  *  'W' - Taint on warning.
  *  'C' - modules from drivers/staging are loaded.
  *
- *	The string is overwritten by the next call to print_taint().
+ *	The string is overwritten by the next call to print_tainted().
  */
 const char *print_tainted(void)
 {
diff --git a/kernel/params.c b/kernel/params.c
index 7f6912ced2b..9da58eabdcb 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -23,6 +23,7 @@
 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/slab.h>
+#include <linux/ctype.h>
 
 #if 0
 #define DEBUGP printk
@@ -87,7 +88,7 @@ static char *next_arg(char *args, char **param, char **val)
 	}
 
 	for (i = 0; args[i]; i++) {
-		if (args[i] == ' ' && !in_quote)
+		if (isspace(args[i]) && !in_quote)
 			break;
 		if (equals == 0) {
 			if (args[i] == '=')
@@ -121,7 +122,7 @@ static char *next_arg(char *args, char **param, char **val)
 		next = args + i;
 
 	/* Chew up trailing spaces. */
-	while (*next == ' ')
+	while (isspace(*next))
 		next++;
 	return next;
 }
@@ -138,7 +139,7 @@ int parse_args(const char *name,
 	DEBUGP("Parsing ARGS: %s\n", args);
 
 	/* Chew leading spaces */
-	while (*args == ' ')
+	while (isspace(*args))
 		args++;
 
 	while (*args) {
diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
deleted file mode 100644
index 8cb94a52d1b..00000000000
--- a/kernel/perf_counter.c
+++ /dev/null
@@ -1,4963 +0,0 @@
-/*
- * Performance counter core code
- *
- *  Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
- *  Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar
- *  Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
- *  Copyright  ©  2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
- *
- *  For licensing details see kernel-base/COPYING
- */
-
-#include <linux/fs.h>
-#include <linux/mm.h>
-#include <linux/cpu.h>
-#include <linux/smp.h>
-#include <linux/file.h>
-#include <linux/poll.h>
-#include <linux/sysfs.h>
-#include <linux/dcache.h>
-#include <linux/percpu.h>
-#include <linux/ptrace.h>
-#include <linux/vmstat.h>
-#include <linux/hardirq.h>
-#include <linux/rculist.h>
-#include <linux/uaccess.h>
-#include <linux/syscalls.h>
-#include <linux/anon_inodes.h>
-#include <linux/kernel_stat.h>
-#include <linux/perf_counter.h>
-
-#include <asm/irq_regs.h>
-
-/*
- * Each CPU has a list of per CPU counters:
- */
-DEFINE_PER_CPU(struct perf_cpu_context, perf_cpu_context);
-
-int perf_max_counters __read_mostly = 1;
-static int perf_reserved_percpu __read_mostly;
-static int perf_overcommit __read_mostly = 1;
-
-static atomic_t nr_counters __read_mostly;
-static atomic_t nr_mmap_counters __read_mostly;
-static atomic_t nr_comm_counters __read_mostly;
-static atomic_t nr_task_counters __read_mostly;
-
-/*
- * perf counter paranoia level:
- *  -1 - not paranoid at all
- *   0 - disallow raw tracepoint access for unpriv
- *   1 - disallow cpu counters for unpriv
- *   2 - disallow kernel profiling for unpriv
- */
-int sysctl_perf_counter_paranoid __read_mostly = 1;
-
-static inline bool perf_paranoid_tracepoint_raw(void)
-{
-	return sysctl_perf_counter_paranoid > -1;
-}
-
-static inline bool perf_paranoid_cpu(void)
-{
-	return sysctl_perf_counter_paranoid > 0;
-}
-
-static inline bool perf_paranoid_kernel(void)
-{
-	return sysctl_perf_counter_paranoid > 1;
-}
-
-int sysctl_perf_counter_mlock __read_mostly = 512; /* 'free' kb per user */
-
-/*
- * max perf counter sample rate
- */
-int sysctl_perf_counter_sample_rate __read_mostly = 100000;
-
-static atomic64_t perf_counter_id;
-
-/*
- * Lock for (sysadmin-configurable) counter reservations:
- */
-static DEFINE_SPINLOCK(perf_resource_lock);
-
-/*
- * Architecture provided APIs - weak aliases:
- */
-extern __weak const struct pmu *hw_perf_counter_init(struct perf_counter *counter)
-{
-	return NULL;
-}
-
-void __weak hw_perf_disable(void)		{ barrier(); }
-void __weak hw_perf_enable(void)		{ barrier(); }
-
-void __weak hw_perf_counter_setup(int cpu)	{ barrier(); }
-void __weak hw_perf_counter_setup_online(int cpu)	{ barrier(); }
-
-int __weak
-hw_perf_group_sched_in(struct perf_counter *group_leader,
-	       struct perf_cpu_context *cpuctx,
-	       struct perf_counter_context *ctx, int cpu)
-{
-	return 0;
-}
-
-void __weak perf_counter_print_debug(void)	{ }
-
-static DEFINE_PER_CPU(int, perf_disable_count);
-
-void __perf_disable(void)
-{
-	__get_cpu_var(perf_disable_count)++;
-}
-
-bool __perf_enable(void)
-{
-	return !--__get_cpu_var(perf_disable_count);
-}
-
-void perf_disable(void)
-{
-	__perf_disable();
-	hw_perf_disable();
-}
-
-void perf_enable(void)
-{
-	if (__perf_enable())
-		hw_perf_enable();
-}
-
-static void get_ctx(struct perf_counter_context *ctx)
-{
-	WARN_ON(!atomic_inc_not_zero(&ctx->refcount));
-}
-
-static void free_ctx(struct rcu_head *head)
-{
-	struct perf_counter_context *ctx;
-
-	ctx = container_of(head, struct perf_counter_context, rcu_head);
-	kfree(ctx);
-}
-
-static void put_ctx(struct perf_counter_context *ctx)
-{
-	if (atomic_dec_and_test(&ctx->refcount)) {
-		if (ctx->parent_ctx)
-			put_ctx(ctx->parent_ctx);
-		if (ctx->task)
-			put_task_struct(ctx->task);
-		call_rcu(&ctx->rcu_head, free_ctx);
-	}
-}
-
-static void unclone_ctx(struct perf_counter_context *ctx)
-{
-	if (ctx->parent_ctx) {
-		put_ctx(ctx->parent_ctx);
-		ctx->parent_ctx = NULL;
-	}
-}
-
-/*
- * If we inherit counters we want to return the parent counter id
- * to userspace.
- */
-static u64 primary_counter_id(struct perf_counter *counter)
-{
-	u64 id = counter->id;
-
-	if (counter->parent)
-		id = counter->parent->id;
-
-	return id;
-}
-
-/*
- * Get the perf_counter_context for a task and lock it.
- * This has to cope with with the fact that until it is locked,
- * the context could get moved to another task.
- */
-static struct perf_counter_context *
-perf_lock_task_context(struct task_struct *task, unsigned long *flags)
-{
-	struct perf_counter_context *ctx;
-
-	rcu_read_lock();
- retry:
-	ctx = rcu_dereference(task->perf_counter_ctxp);
-	if (ctx) {
-		/*
-		 * If this context is a clone of another, it might
-		 * get swapped for another underneath us by
-		 * perf_counter_task_sched_out, though the
-		 * rcu_read_lock() protects us from any context
-		 * getting freed.  Lock the context and check if it
-		 * got swapped before we could get the lock, and retry
-		 * if so.  If we locked the right context, then it
-		 * can't get swapped on us any more.
-		 */
-		spin_lock_irqsave(&ctx->lock, *flags);
-		if (ctx != rcu_dereference(task->perf_counter_ctxp)) {
-			spin_unlock_irqrestore(&ctx->lock, *flags);
-			goto retry;
-		}
-
-		if (!atomic_inc_not_zero(&ctx->refcount)) {
-			spin_unlock_irqrestore(&ctx->lock, *flags);
-			ctx = NULL;
-		}
-	}
-	rcu_read_unlock();
-	return ctx;
-}
-
-/*
- * Get the context for a task and increment its pin_count so it
- * can't get swapped to another task.  This also increments its
- * reference count so that the context can't get freed.
- */
-static struct perf_counter_context *perf_pin_task_context(struct task_struct *task)
-{
-	struct perf_counter_context *ctx;
-	unsigned long flags;
-
-	ctx = perf_lock_task_context(task, &flags);
-	if (ctx) {
-		++ctx->pin_count;
-		spin_unlock_irqrestore(&ctx->lock, flags);
-	}
-	return ctx;
-}
-
-static void perf_unpin_context(struct perf_counter_context *ctx)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&ctx->lock, flags);
-	--ctx->pin_count;
-	spin_unlock_irqrestore(&ctx->lock, flags);
-	put_ctx(ctx);
-}
-
-/*
- * Add a counter from the lists for its context.
- * Must be called with ctx->mutex and ctx->lock held.
- */
-static void
-list_add_counter(struct perf_counter *counter, struct perf_counter_context *ctx)
-{
-	struct perf_counter *group_leader = counter->group_leader;
-
-	/*
-	 * Depending on whether it is a standalone or sibling counter,
-	 * add it straight to the context's counter list, or to the group
-	 * leader's sibling list:
-	 */
-	if (group_leader == counter)
-		list_add_tail(&counter->list_entry, &ctx->counter_list);
-	else {
-		list_add_tail(&counter->list_entry, &group_leader->sibling_list);
-		group_leader->nr_siblings++;
-	}
-
-	list_add_rcu(&counter->event_entry, &ctx->event_list);
-	ctx->nr_counters++;
-	if (counter->attr.inherit_stat)
-		ctx->nr_stat++;
-}
-
-/*
- * Remove a counter from the lists for its context.
- * Must be called with ctx->mutex and ctx->lock held.
- */
-static void
-list_del_counter(struct perf_counter *counter, struct perf_counter_context *ctx)
-{
-	struct perf_counter *sibling, *tmp;
-
-	if (list_empty(&counter->list_entry))
-		return;
-	ctx->nr_counters--;
-	if (counter->attr.inherit_stat)
-		ctx->nr_stat--;
-
-	list_del_init(&counter->list_entry);
-	list_del_rcu(&counter->event_entry);
-
-	if (counter->group_leader != counter)
-		counter->group_leader->nr_siblings--;
-
-	/*
-	 * If this was a group counter with sibling counters then
-	 * upgrade the siblings to singleton counters by adding them
-	 * to the context list directly:
-	 */
-	list_for_each_entry_safe(sibling, tmp,
-				 &counter->sibling_list, list_entry) {
-
-		list_move_tail(&sibling->list_entry, &ctx->counter_list);
-		sibling->group_leader = sibling;
-	}
-}
-
-static void
-counter_sched_out(struct perf_counter *counter,
-		  struct perf_cpu_context *cpuctx,
-		  struct perf_counter_context *ctx)
-{
-	if (counter->state != PERF_COUNTER_STATE_ACTIVE)
-		return;
-
-	counter->state = PERF_COUNTER_STATE_INACTIVE;
-	if (counter->pending_disable) {
-		counter->pending_disable = 0;
-		counter->state = PERF_COUNTER_STATE_OFF;
-	}
-	counter->tstamp_stopped = ctx->time;
-	counter->pmu->disable(counter);
-	counter->oncpu = -1;
-
-	if (!is_software_counter(counter))
-		cpuctx->active_oncpu--;
-	ctx->nr_active--;
-	if (counter->attr.exclusive || !cpuctx->active_oncpu)
-		cpuctx->exclusive = 0;
-}
-
-static void
-group_sched_out(struct perf_counter *group_counter,
-		struct perf_cpu_context *cpuctx,
-		struct perf_counter_context *ctx)
-{
-	struct perf_counter *counter;
-
-	if (group_counter->state != PERF_COUNTER_STATE_ACTIVE)
-		return;
-
-	counter_sched_out(group_counter, cpuctx, ctx);
-
-	/*
-	 * Schedule out siblings (if any):
-	 */
-	list_for_each_entry(counter, &group_counter->sibling_list, list_entry)
-		counter_sched_out(counter, cpuctx, ctx);
-
-	if (group_counter->attr.exclusive)
-		cpuctx->exclusive = 0;
-}
-
-/*
- * Cross CPU call to remove a performance counter
- *
- * We disable the counter on the hardware level first. After that we
- * remove it from the context list.
- */
-static void __perf_counter_remove_from_context(void *info)
-{
-	struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
-	struct perf_counter *counter = info;
-	struct perf_counter_context *ctx = counter->ctx;
-
-	/*
-	 * If this is a task context, we need to check whether it is
-	 * the current task context of this cpu. If not it has been
-	 * scheduled out before the smp call arrived.
-	 */
-	if (ctx->task && cpuctx->task_ctx != ctx)
-		return;
-
-	spin_lock(&ctx->lock);
-	/*
-	 * Protect the list operation against NMI by disabling the
-	 * counters on a global level.
-	 */
-	perf_disable();
-
-	counter_sched_out(counter, cpuctx, ctx);
-
-	list_del_counter(counter, ctx);
-
-	if (!ctx->task) {
-		/*
-		 * Allow more per task counters with respect to the
-		 * reservation:
-		 */
-		cpuctx->max_pertask =
-			min(perf_max_counters - ctx->nr_counters,
-			    perf_max_counters - perf_reserved_percpu);
-	}
-
-	perf_enable();
-	spin_unlock(&ctx->lock);
-}
-
-
-/*
- * Remove the counter from a task's (or a CPU's) list of counters.
- *
- * Must be called with ctx->mutex held.
- *
- * CPU counters are removed with a smp call. For task counters we only
- * call when the task is on a CPU.
- *
- * If counter->ctx is a cloned context, callers must make sure that
- * every task struct that counter->ctx->task could possibly point to
- * remains valid.  This is OK when called from perf_release since
- * that only calls us on the top-level context, which can't be a clone.
- * When called from perf_counter_exit_task, it's OK because the
- * context has been detached from its task.
- */
-static void perf_counter_remove_from_context(struct perf_counter *counter)
-{
-	struct perf_counter_context *ctx = counter->ctx;
-	struct task_struct *task = ctx->task;
-
-	if (!task) {
-		/*
-		 * Per cpu counters are removed via an smp call and
-		 * the removal is always sucessful.
-		 */
-		smp_call_function_single(counter->cpu,
-					 __perf_counter_remove_from_context,
-					 counter, 1);
-		return;
-	}
-
-retry:
-	task_oncpu_function_call(task, __perf_counter_remove_from_context,
-				 counter);
-
-	spin_lock_irq(&ctx->lock);
-	/*
-	 * If the context is active we need to retry the smp call.
-	 */
-	if (ctx->nr_active && !list_empty(&counter->list_entry)) {
-		spin_unlock_irq(&ctx->lock);
-		goto retry;
-	}
-
-	/*
-	 * The lock prevents that this context is scheduled in so we
-	 * can remove the counter safely, if the call above did not
-	 * succeed.
-	 */
-	if (!list_empty(&counter->list_entry)) {
-		list_del_counter(counter, ctx);
-	}
-	spin_unlock_irq(&ctx->lock);
-}
-
-static inline u64 perf_clock(void)
-{
-	return cpu_clock(smp_processor_id());
-}
-
-/*
- * Update the record of the current time in a context.
- */
-static void update_context_time(struct perf_counter_context *ctx)
-{
-	u64 now = perf_clock();
-
-	ctx->time += now - ctx->timestamp;
-	ctx->timestamp = now;
-}
-
-/*
- * Update the total_time_enabled and total_time_running fields for a counter.
- */
-static void update_counter_times(struct perf_counter *counter)
-{
-	struct perf_counter_context *ctx = counter->ctx;
-	u64 run_end;
-
-	if (counter->state < PERF_COUNTER_STATE_INACTIVE ||
-	    counter->group_leader->state < PERF_COUNTER_STATE_INACTIVE)
-		return;
-
-	counter->total_time_enabled = ctx->time - counter->tstamp_enabled;
-
-	if (counter->state == PERF_COUNTER_STATE_INACTIVE)
-		run_end = counter->tstamp_stopped;
-	else
-		run_end = ctx->time;
-
-	counter->total_time_running = run_end - counter->tstamp_running;
-}
-
-/*
- * Update total_time_enabled and total_time_running for all counters in a group.
- */
-static void update_group_times(struct perf_counter *leader)
-{
-	struct perf_counter *counter;
-
-	update_counter_times(leader);
-	list_for_each_entry(counter, &leader->sibling_list, list_entry)
-		update_counter_times(counter);
-}
-
-/*
- * Cross CPU call to disable a performance counter
- */
-static void __perf_counter_disable(void *info)
-{
-	struct perf_counter *counter = info;
-	struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
-	struct perf_counter_context *ctx = counter->ctx;
-
-	/*
-	 * If this is a per-task counter, need to check whether this
-	 * counter's task is the current task on this cpu.
-	 */
-	if (ctx->task && cpuctx->task_ctx != ctx)
-		return;
-
-	spin_lock(&ctx->lock);
-
-	/*
-	 * If the counter is on, turn it off.
-	 * If it is in error state, leave it in error state.
-	 */
-	if (counter->state >= PERF_COUNTER_STATE_INACTIVE) {
-		update_context_time(ctx);
-		update_group_times(counter);
-		if (counter == counter->group_leader)
-			group_sched_out(counter, cpuctx, ctx);
-		else
-			counter_sched_out(counter, cpuctx, ctx);
-		counter->state = PERF_COUNTER_STATE_OFF;
-	}
-
-	spin_unlock(&ctx->lock);
-}
-
-/*
- * Disable a counter.
- *
- * If counter->ctx is a cloned context, callers must make sure that
- * every task struct that counter->ctx->task could possibly point to
- * remains valid.  This condition is satisifed when called through
- * perf_counter_for_each_child or perf_counter_for_each because they
- * hold the top-level counter's child_mutex, so any descendant that
- * goes to exit will block in sync_child_counter.
- * When called from perf_pending_counter it's OK because counter->ctx
- * is the current context on this CPU and preemption is disabled,
- * hence we can't get into perf_counter_task_sched_out for this context.
- */
-static void perf_counter_disable(struct perf_counter *counter)
-{
-	struct perf_counter_context *ctx = counter->ctx;
-	struct task_struct *task = ctx->task;
-
-	if (!task) {
-		/*
-		 * Disable the counter on the cpu that it's on
-		 */
-		smp_call_function_single(counter->cpu, __perf_counter_disable,
-					 counter, 1);
-		return;
-	}
-
- retry:
-	task_oncpu_function_call(task, __perf_counter_disable, counter);
-
-	spin_lock_irq(&ctx->lock);
-	/*
-	 * If the counter is still active, we need to retry the cross-call.
-	 */
-	if (counter->state == PERF_COUNTER_STATE_ACTIVE) {
-		spin_unlock_irq(&ctx->lock);
-		goto retry;
-	}
-
-	/*
-	 * Since we have the lock this context can't be scheduled
-	 * in, so we can change the state safely.
-	 */
-	if (counter->state == PERF_COUNTER_STATE_INACTIVE) {
-		update_group_times(counter);
-		counter->state = PERF_COUNTER_STATE_OFF;
-	}
-
-	spin_unlock_irq(&ctx->lock);
-}
-
-static int
-counter_sched_in(struct perf_counter *counter,
-		 struct perf_cpu_context *cpuctx,
-		 struct perf_counter_context *ctx,
-		 int cpu)
-{
-	if (counter->state <= PERF_COUNTER_STATE_OFF)
-		return 0;
-
-	counter->state = PERF_COUNTER_STATE_ACTIVE;
-	counter->oncpu = cpu;	/* TODO: put 'cpu' into cpuctx->cpu */
-	/*
-	 * The new state must be visible before we turn it on in the hardware:
-	 */
-	smp_wmb();
-
-	if (counter->pmu->enable(counter)) {
-		counter->state = PERF_COUNTER_STATE_INACTIVE;
-		counter->oncpu = -1;
-		return -EAGAIN;
-	}
-
-	counter->tstamp_running += ctx->time - counter->tstamp_stopped;
-
-	if (!is_software_counter(counter))
-		cpuctx->active_oncpu++;
-	ctx->nr_active++;
-
-	if (counter->attr.exclusive)
-		cpuctx->exclusive = 1;
-
-	return 0;
-}
-
-static int
-group_sched_in(struct perf_counter *group_counter,
-	       struct perf_cpu_context *cpuctx,
-	       struct perf_counter_context *ctx,
-	       int cpu)
-{
-	struct perf_counter *counter, *partial_group;
-	int ret;
-
-	if (group_counter->state == PERF_COUNTER_STATE_OFF)
-		return 0;
-
-	ret = hw_perf_group_sched_in(group_counter, cpuctx, ctx, cpu);
-	if (ret)
-		return ret < 0 ? ret : 0;
-
-	if (counter_sched_in(group_counter, cpuctx, ctx, cpu))
-		return -EAGAIN;
-
-	/*
-	 * Schedule in siblings as one group (if any):
-	 */
-	list_for_each_entry(counter, &group_counter->sibling_list, list_entry) {
-		if (counter_sched_in(counter, cpuctx, ctx, cpu)) {
-			partial_group = counter;
-			goto group_error;
-		}
-	}
-
-	return 0;
-
-group_error:
-	/*
-	 * Groups can be scheduled in as one unit only, so undo any
-	 * partial group before returning:
-	 */
-	list_for_each_entry(counter, &group_counter->sibling_list, list_entry) {
-		if (counter == partial_group)
-			break;
-		counter_sched_out(counter, cpuctx, ctx);
-	}
-	counter_sched_out(group_counter, cpuctx, ctx);
-
-	return -EAGAIN;
-}
-
-/*
- * Return 1 for a group consisting entirely of software counters,
- * 0 if the group contains any hardware counters.
- */
-static int is_software_only_group(struct perf_counter *leader)
-{
-	struct perf_counter *counter;
-
-	if (!is_software_counter(leader))
-		return 0;
-
-	list_for_each_entry(counter, &leader->sibling_list, list_entry)
-		if (!is_software_counter(counter))
-			return 0;
-
-	return 1;
-}
-
-/*
- * Work out whether we can put this counter group on the CPU now.
- */
-static int group_can_go_on(struct perf_counter *counter,
-			   struct perf_cpu_context *cpuctx,
-			   int can_add_hw)
-{
-	/*
-	 * Groups consisting entirely of software counters can always go on.
-	 */
-	if (is_software_only_group(counter))
-		return 1;
-	/*
-	 * If an exclusive group is already on, no other hardware
-	 * counters can go on.
-	 */
-	if (cpuctx->exclusive)
-		return 0;
-	/*
-	 * If this group is exclusive and there are already
-	 * counters on the CPU, it can't go on.
-	 */
-	if (counter->attr.exclusive && cpuctx->active_oncpu)
-		return 0;
-	/*
-	 * Otherwise, try to add it if all previous groups were able
-	 * to go on.
-	 */
-	return can_add_hw;
-}
-
-static void add_counter_to_ctx(struct perf_counter *counter,
-			       struct perf_counter_context *ctx)
-{
-	list_add_counter(counter, ctx);
-	counter->tstamp_enabled = ctx->time;
-	counter->tstamp_running = ctx->time;
-	counter->tstamp_stopped = ctx->time;
-}
-
-/*
- * Cross CPU call to install and enable a performance counter
- *
- * Must be called with ctx->mutex held
- */
-static void __perf_install_in_context(void *info)
-{
-	struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
-	struct perf_counter *counter = info;
-	struct perf_counter_context *ctx = counter->ctx;
-	struct perf_counter *leader = counter->group_leader;
-	int cpu = smp_processor_id();
-	int err;
-
-	/*
-	 * If this is a task context, we need to check whether it is
-	 * the current task context of this cpu. If not it has been
-	 * scheduled out before the smp call arrived.
-	 * Or possibly this is the right context but it isn't
-	 * on this cpu because it had no counters.
-	 */
-	if (ctx->task && cpuctx->task_ctx != ctx) {
-		if (cpuctx->task_ctx || ctx->task != current)
-			return;
-		cpuctx->task_ctx = ctx;
-	}
-
-	spin_lock(&ctx->lock);
-	ctx->is_active = 1;
-	update_context_time(ctx);
-
-	/*
-	 * Protect the list operation against NMI by disabling the
-	 * counters on a global level. NOP for non NMI based counters.
-	 */
-	perf_disable();
-
-	add_counter_to_ctx(counter, ctx);
-
-	/*
-	 * Don't put the counter on if it is disabled or if
-	 * it is in a group and the group isn't on.
-	 */
-	if (counter->state != PERF_COUNTER_STATE_INACTIVE ||
-	    (leader != counter && leader->state != PERF_COUNTER_STATE_ACTIVE))
-		goto unlock;
-
-	/*
-	 * An exclusive counter can't go on if there are already active
-	 * hardware counters, and no hardware counter can go on if there
-	 * is already an exclusive counter on.
-	 */
-	if (!group_can_go_on(counter, cpuctx, 1))
-		err = -EEXIST;
-	else
-		err = counter_sched_in(counter, cpuctx, ctx, cpu);
-
-	if (err) {
-		/*
-		 * This counter couldn't go on.  If it is in a group
-		 * then we have to pull the whole group off.
-		 * If the counter group is pinned then put it in error state.
-		 */
-		if (leader != counter)
-			group_sched_out(leader, cpuctx, ctx);
-		if (leader->attr.pinned) {
-			update_group_times(leader);
-			leader->state = PERF_COUNTER_STATE_ERROR;
-		}
-	}
-
-	if (!err && !ctx->task && cpuctx->max_pertask)
-		cpuctx->max_pertask--;
-
- unlock:
-	perf_enable();
-
-	spin_unlock(&ctx->lock);
-}
-
-/*
- * Attach a performance counter to a context
- *
- * First we add the counter to the list with the hardware enable bit
- * in counter->hw_config cleared.
- *
- * If the counter is attached to a task which is on a CPU we use a smp
- * call to enable it in the task context. The task might have been
- * scheduled away, but we check this in the smp call again.
- *
- * Must be called with ctx->mutex held.
- */
-static void
-perf_install_in_context(struct perf_counter_context *ctx,
-			struct perf_counter *counter,
-			int cpu)
-{
-	struct task_struct *task = ctx->task;
-
-	if (!task) {
-		/*
-		 * Per cpu counters are installed via an smp call and
-		 * the install is always sucessful.
-		 */
-		smp_call_function_single(cpu, __perf_install_in_context,
-					 counter, 1);
-		return;
-	}
-
-retry:
-	task_oncpu_function_call(task, __perf_install_in_context,
-				 counter);
-
-	spin_lock_irq(&ctx->lock);
-	/*
-	 * we need to retry the smp call.
-	 */
-	if (ctx->is_active && list_empty(&counter->list_entry)) {
-		spin_unlock_irq(&ctx->lock);
-		goto retry;
-	}
-
-	/*
-	 * The lock prevents that this context is scheduled in so we
-	 * can add the counter safely, if it the call above did not
-	 * succeed.
-	 */
-	if (list_empty(&counter->list_entry))
-		add_counter_to_ctx(counter, ctx);
-	spin_unlock_irq(&ctx->lock);
-}
-
-/*
- * Put a counter into inactive state and update time fields.
- * Enabling the leader of a group effectively enables all
- * the group members that aren't explicitly disabled, so we
- * have to update their ->tstamp_enabled also.
- * Note: this works for group members as well as group leaders
- * since the non-leader members' sibling_lists will be empty.
- */
-static void __perf_counter_mark_enabled(struct perf_counter *counter,
-					struct perf_counter_context *ctx)
-{
-	struct perf_counter *sub;
-
-	counter->state = PERF_COUNTER_STATE_INACTIVE;
-	counter->tstamp_enabled = ctx->time - counter->total_time_enabled;
-	list_for_each_entry(sub, &counter->sibling_list, list_entry)
-		if (sub->state >= PERF_COUNTER_STATE_INACTIVE)
-			sub->tstamp_enabled =
-				ctx->time - sub->total_time_enabled;
-}
-
-/*
- * Cross CPU call to enable a performance counter
- */
-static void __perf_counter_enable(void *info)
-{
-	struct perf_counter *counter = info;
-	struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
-	struct perf_counter_context *ctx = counter->ctx;
-	struct perf_counter *leader = counter->group_leader;
-	int err;
-
-	/*
-	 * If this is a per-task counter, need to check whether this
-	 * counter's task is the current task on this cpu.
-	 */
-	if (ctx->task && cpuctx->task_ctx != ctx) {
-		if (cpuctx->task_ctx || ctx->task != current)
-			return;
-		cpuctx->task_ctx = ctx;
-	}
-
-	spin_lock(&ctx->lock);
-	ctx->is_active = 1;
-	update_context_time(ctx);
-
-	if (counter->state >= PERF_COUNTER_STATE_INACTIVE)
-		goto unlock;
-	__perf_counter_mark_enabled(counter, ctx);
-
-	/*
-	 * If the counter is in a group and isn't the group leader,
-	 * then don't put it on unless the group is on.
-	 */
-	if (leader != counter && leader->state != PERF_COUNTER_STATE_ACTIVE)
-		goto unlock;
-
-	if (!group_can_go_on(counter, cpuctx, 1)) {
-		err = -EEXIST;
-	} else {
-		perf_disable();
-		if (counter == leader)
-			err = group_sched_in(counter, cpuctx, ctx,
-					     smp_processor_id());
-		else
-			err = counter_sched_in(counter, cpuctx, ctx,
-					       smp_processor_id());
-		perf_enable();
-	}
-
-	if (err) {
-		/*
-		 * If this counter can't go on and it's part of a
-		 * group, then the whole group has to come off.
-		 */
-		if (leader != counter)
-			group_sched_out(leader, cpuctx, ctx);
-		if (leader->attr.pinned) {
-			update_group_times(leader);
-			leader->state = PERF_COUNTER_STATE_ERROR;
-		}
-	}
-
- unlock:
-	spin_unlock(&ctx->lock);
-}
-
-/*
- * Enable a counter.
- *
- * If counter->ctx is a cloned context, callers must make sure that
- * every task struct that counter->ctx->task could possibly point to
- * remains valid.  This condition is satisfied when called through
- * perf_counter_for_each_child or perf_counter_for_each as described
- * for perf_counter_disable.
- */
-static void perf_counter_enable(struct perf_counter *counter)
-{
-	struct perf_counter_context *ctx = counter->ctx;
-	struct task_struct *task = ctx->task;
-
-	if (!task) {
-		/*
-		 * Enable the counter on the cpu that it's on
-		 */
-		smp_call_function_single(counter->cpu, __perf_counter_enable,
-					 counter, 1);
-		return;
-	}
-
-	spin_lock_irq(&ctx->lock);
-	if (counter->state >= PERF_COUNTER_STATE_INACTIVE)
-		goto out;
-
-	/*
-	 * If the counter is in error state, clear that first.
-	 * That way, if we see the counter in error state below, we
-	 * know that it has gone back into error state, as distinct
-	 * from the task having been scheduled away before the
-	 * cross-call arrived.
-	 */
-	if (counter->state == PERF_COUNTER_STATE_ERROR)
-		counter->state = PERF_COUNTER_STATE_OFF;
-
- retry:
-	spin_unlock_irq(&ctx->lock);
-	task_oncpu_function_call(task, __perf_counter_enable, counter);
-
-	spin_lock_irq(&ctx->lock);
-
-	/*
-	 * If the context is active and the counter is still off,
-	 * we need to retry the cross-call.
-	 */
-	if (ctx->is_active && counter->state == PERF_COUNTER_STATE_OFF)
-		goto retry;
-
-	/*
-	 * Since we have the lock this context can't be scheduled
-	 * in, so we can change the state safely.
-	 */
-	if (counter->state == PERF_COUNTER_STATE_OFF)
-		__perf_counter_mark_enabled(counter, ctx);
-
- out:
-	spin_unlock_irq(&ctx->lock);
-}
-
-static int perf_counter_refresh(struct perf_counter *counter, int refresh)
-{
-	/*
-	 * not supported on inherited counters
-	 */
-	if (counter->attr.inherit)
-		return -EINVAL;
-
-	atomic_add(refresh, &counter->event_limit);
-	perf_counter_enable(counter);
-
-	return 0;
-}
-
-void __perf_counter_sched_out(struct perf_counter_context *ctx,
-			      struct perf_cpu_context *cpuctx)
-{
-	struct perf_counter *counter;
-
-	spin_lock(&ctx->lock);
-	ctx->is_active = 0;
-	if (likely(!ctx->nr_counters))
-		goto out;
-	update_context_time(ctx);
-
-	perf_disable();
-	if (ctx->nr_active) {
-		list_for_each_entry(counter, &ctx->counter_list, list_entry) {
-			if (counter != counter->group_leader)
-				counter_sched_out(counter, cpuctx, ctx);
-			else
-				group_sched_out(counter, cpuctx, ctx);
-		}
-	}
-	perf_enable();
- out:
-	spin_unlock(&ctx->lock);
-}
-
-/*
- * Test whether two contexts are equivalent, i.e. whether they
- * have both been cloned from the same version of the same context
- * and they both have the same number of enabled counters.
- * If the number of enabled counters is the same, then the set
- * of enabled counters should be the same, because these are both
- * inherited contexts, therefore we can't access individual counters
- * in them directly with an fd; we can only enable/disable all
- * counters via prctl, or enable/disable all counters in a family
- * via ioctl, which will have the same effect on both contexts.
- */
-static int context_equiv(struct perf_counter_context *ctx1,
-			 struct perf_counter_context *ctx2)
-{
-	return ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx
-		&& ctx1->parent_gen == ctx2->parent_gen
-		&& !ctx1->pin_count && !ctx2->pin_count;
-}
-
-static void __perf_counter_read(void *counter);
-
-static void __perf_counter_sync_stat(struct perf_counter *counter,
-				     struct perf_counter *next_counter)
-{
-	u64 value;
-
-	if (!counter->attr.inherit_stat)
-		return;
-
-	/*
-	 * Update the counter value, we cannot use perf_counter_read()
-	 * because we're in the middle of a context switch and have IRQs
-	 * disabled, which upsets smp_call_function_single(), however
-	 * we know the counter must be on the current CPU, therefore we
-	 * don't need to use it.
-	 */
-	switch (counter->state) {
-	case PERF_COUNTER_STATE_ACTIVE:
-		__perf_counter_read(counter);
-		break;
-
-	case PERF_COUNTER_STATE_INACTIVE:
-		update_counter_times(counter);
-		break;
-
-	default:
-		break;
-	}
-
-	/*
-	 * In order to keep per-task stats reliable we need to flip the counter
-	 * values when we flip the contexts.
-	 */
-	value = atomic64_read(&next_counter->count);
-	value = atomic64_xchg(&counter->count, value);
-	atomic64_set(&next_counter->count, value);
-
-	swap(counter->total_time_enabled, next_counter->total_time_enabled);
-	swap(counter->total_time_running, next_counter->total_time_running);
-
-	/*
-	 * Since we swizzled the values, update the user visible data too.
-	 */
-	perf_counter_update_userpage(counter);
-	perf_counter_update_userpage(next_counter);
-}
-
-#define list_next_entry(pos, member) \
-	list_entry(pos->member.next, typeof(*pos), member)
-
-static void perf_counter_sync_stat(struct perf_counter_context *ctx,
-				   struct perf_counter_context *next_ctx)
-{
-	struct perf_counter *counter, *next_counter;
-
-	if (!ctx->nr_stat)
-		return;
-
-	counter = list_first_entry(&ctx->event_list,
-				   struct perf_counter, event_entry);
-
-	next_counter = list_first_entry(&next_ctx->event_list,
-					struct perf_counter, event_entry);
-
-	while (&counter->event_entry != &ctx->event_list &&
-	       &next_counter->event_entry != &next_ctx->event_list) {
-
-		__perf_counter_sync_stat(counter, next_counter);
-
-		counter = list_next_entry(counter, event_entry);
-		next_counter = list_next_entry(next_counter, event_entry);
-	}
-}
-
-/*
- * Called from scheduler to remove the counters of the current task,
- * with interrupts disabled.
- *
- * We stop each counter and update the counter value in counter->count.
- *
- * This does not protect us against NMI, but disable()
- * sets the disabled bit in the control field of counter _before_
- * accessing the counter control register. If a NMI hits, then it will
- * not restart the counter.
- */
-void perf_counter_task_sched_out(struct task_struct *task,
-				 struct task_struct *next, int cpu)
-{
-	struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu);
-	struct perf_counter_context *ctx = task->perf_counter_ctxp;
-	struct perf_counter_context *next_ctx;
-	struct perf_counter_context *parent;
-	struct pt_regs *regs;
-	int do_switch = 1;
-
-	regs = task_pt_regs(task);
-	perf_swcounter_event(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, 1, regs, 0);
-
-	if (likely(!ctx || !cpuctx->task_ctx))
-		return;
-
-	update_context_time(ctx);
-
-	rcu_read_lock();
-	parent = rcu_dereference(ctx->parent_ctx);
-	next_ctx = next->perf_counter_ctxp;
-	if (parent && next_ctx &&
-	    rcu_dereference(next_ctx->parent_ctx) == parent) {
-		/*
-		 * Looks like the two contexts are clones, so we might be
-		 * able to optimize the context switch.  We lock both
-		 * contexts and check that they are clones under the
-		 * lock (including re-checking that neither has been
-		 * uncloned in the meantime).  It doesn't matter which
-		 * order we take the locks because no other cpu could
-		 * be trying to lock both of these tasks.
-		 */
-		spin_lock(&ctx->lock);
-		spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING);
-		if (context_equiv(ctx, next_ctx)) {
-			/*
-			 * XXX do we need a memory barrier of sorts
-			 * wrt to rcu_dereference() of perf_counter_ctxp
-			 */
-			task->perf_counter_ctxp = next_ctx;
-			next->perf_counter_ctxp = ctx;
-			ctx->task = next;
-			next_ctx->task = task;
-			do_switch = 0;
-
-			perf_counter_sync_stat(ctx, next_ctx);
-		}
-		spin_unlock(&next_ctx->lock);
-		spin_unlock(&ctx->lock);
-	}
-	rcu_read_unlock();
-
-	if (do_switch) {
-		__perf_counter_sched_out(ctx, cpuctx);
-		cpuctx->task_ctx = NULL;
-	}
-}
-
-/*
- * Called with IRQs disabled
- */
-static void __perf_counter_task_sched_out(struct perf_counter_context *ctx)
-{
-	struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
-
-	if (!cpuctx->task_ctx)
-		return;
-
-	if (WARN_ON_ONCE(ctx != cpuctx->task_ctx))
-		return;
-
-	__perf_counter_sched_out(ctx, cpuctx);
-	cpuctx->task_ctx = NULL;
-}
-
-/*
- * Called with IRQs disabled
- */
-static void perf_counter_cpu_sched_out(struct perf_cpu_context *cpuctx)
-{
-	__perf_counter_sched_out(&cpuctx->ctx, cpuctx);
-}
-
-static void
-__perf_counter_sched_in(struct perf_counter_context *ctx,
-			struct perf_cpu_context *cpuctx, int cpu)
-{
-	struct perf_counter *counter;
-	int can_add_hw = 1;
-
-	spin_lock(&ctx->lock);
-	ctx->is_active = 1;
-	if (likely(!ctx->nr_counters))
-		goto out;
-
-	ctx->timestamp = perf_clock();
-
-	perf_disable();
-
-	/*
-	 * First go through the list and put on any pinned groups
-	 * in order to give them the best chance of going on.
-	 */
-	list_for_each_entry(counter, &ctx->counter_list, list_entry) {
-		if (counter->state <= PERF_COUNTER_STATE_OFF ||
-		    !counter->attr.pinned)
-			continue;
-		if (counter->cpu != -1 && counter->cpu != cpu)
-			continue;
-
-		if (counter != counter->group_leader)
-			counter_sched_in(counter, cpuctx, ctx, cpu);
-		else {
-			if (group_can_go_on(counter, cpuctx, 1))
-				group_sched_in(counter, cpuctx, ctx, cpu);
-		}
-
-		/*
-		 * If this pinned group hasn't been scheduled,
-		 * put it in error state.
-		 */
-		if (counter->state == PERF_COUNTER_STATE_INACTIVE) {
-			update_group_times(counter);
-			counter->state = PERF_COUNTER_STATE_ERROR;
-		}
-	}
-
-	list_for_each_entry(counter, &ctx->counter_list, list_entry) {
-		/*
-		 * Ignore counters in OFF or ERROR state, and
-		 * ignore pinned counters since we did them already.
-		 */
-		if (counter->state <= PERF_COUNTER_STATE_OFF ||
-		    counter->attr.pinned)
-			continue;
-
-		/*
-		 * Listen to the 'cpu' scheduling filter constraint
-		 * of counters:
-		 */
-		if (counter->cpu != -1 && counter->cpu != cpu)
-			continue;
-
-		if (counter != counter->group_leader) {
-			if (counter_sched_in(counter, cpuctx, ctx, cpu))
-				can_add_hw = 0;
-		} else {
-			if (group_can_go_on(counter, cpuctx, can_add_hw)) {
-				if (group_sched_in(counter, cpuctx, ctx, cpu))
-					can_add_hw = 0;
-			}
-		}
-	}
-	perf_enable();
- out:
-	spin_unlock(&ctx->lock);
-}
-
-/*
- * Called from scheduler to add the counters of the current task
- * with interrupts disabled.
- *
- * We restore the counter value and then enable it.
- *
- * This does not protect us against NMI, but enable()
- * sets the enabled bit in the control field of counter _before_
- * accessing the counter control register. If a NMI hits, then it will
- * keep the counter running.
- */
-void perf_counter_task_sched_in(struct task_struct *task, int cpu)
-{
-	struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu);
-	struct perf_counter_context *ctx = task->perf_counter_ctxp;
-
-	if (likely(!ctx))
-		return;
-	if (cpuctx->task_ctx == ctx)
-		return;
-	__perf_counter_sched_in(ctx, cpuctx, cpu);
-	cpuctx->task_ctx = ctx;
-}
-
-static void perf_counter_cpu_sched_in(struct perf_cpu_context *cpuctx, int cpu)
-{
-	struct perf_counter_context *ctx = &cpuctx->ctx;
-
-	__perf_counter_sched_in(ctx, cpuctx, cpu);
-}
-
-#define MAX_INTERRUPTS (~0ULL)
-
-static void perf_log_throttle(struct perf_counter *counter, int enable);
-
-static void perf_adjust_period(struct perf_counter *counter, u64 events)
-{
-	struct hw_perf_counter *hwc = &counter->hw;
-	u64 period, sample_period;
-	s64 delta;
-
-	events *= hwc->sample_period;
-	period = div64_u64(events, counter->attr.sample_freq);
-
-	delta = (s64)(period - hwc->sample_period);
-	delta = (delta + 7) / 8; /* low pass filter */
-
-	sample_period = hwc->sample_period + delta;
-
-	if (!sample_period)
-		sample_period = 1;
-
-	hwc->sample_period = sample_period;
-}
-
-static void perf_ctx_adjust_freq(struct perf_counter_context *ctx)
-{
-	struct perf_counter *counter;
-	struct hw_perf_counter *hwc;
-	u64 interrupts, freq;
-
-	spin_lock(&ctx->lock);
-	list_for_each_entry(counter, &ctx->counter_list, list_entry) {
-		if (counter->state != PERF_COUNTER_STATE_ACTIVE)
-			continue;
-
-		hwc = &counter->hw;
-
-		interrupts = hwc->interrupts;
-		hwc->interrupts = 0;
-
-		/*
-		 * unthrottle counters on the tick
-		 */
-		if (interrupts == MAX_INTERRUPTS) {
-			perf_log_throttle(counter, 1);
-			counter->pmu->unthrottle(counter);
-			interrupts = 2*sysctl_perf_counter_sample_rate/HZ;
-		}
-
-		if (!counter->attr.freq || !counter->attr.sample_freq)
-			continue;
-
-		/*
-		 * if the specified freq < HZ then we need to skip ticks
-		 */
-		if (counter->attr.sample_freq < HZ) {
-			freq = counter->attr.sample_freq;
-
-			hwc->freq_count += freq;
-			hwc->freq_interrupts += interrupts;
-
-			if (hwc->freq_count < HZ)
-				continue;
-
-			interrupts = hwc->freq_interrupts;
-			hwc->freq_interrupts = 0;
-			hwc->freq_count -= HZ;
-		} else
-			freq = HZ;
-
-		perf_adjust_period(counter, freq * interrupts);
-
-		/*
-		 * In order to avoid being stalled by an (accidental) huge
-		 * sample period, force reset the sample period if we didn't
-		 * get any events in this freq period.
-		 */
-		if (!interrupts) {
-			perf_disable();
-			counter->pmu->disable(counter);
-			atomic64_set(&hwc->period_left, 0);
-			counter->pmu->enable(counter);
-			perf_enable();
-		}
-	}
-	spin_unlock(&ctx->lock);
-}
-
-/*
- * Round-robin a context's counters:
- */
-static void rotate_ctx(struct perf_counter_context *ctx)
-{
-	struct perf_counter *counter;
-
-	if (!ctx->nr_counters)
-		return;
-
-	spin_lock(&ctx->lock);
-	/*
-	 * Rotate the first entry last (works just fine for group counters too):
-	 */
-	perf_disable();
-	list_for_each_entry(counter, &ctx->counter_list, list_entry) {
-		list_move_tail(&counter->list_entry, &ctx->counter_list);
-		break;
-	}
-	perf_enable();
-
-	spin_unlock(&ctx->lock);
-}
-
-void perf_counter_task_tick(struct task_struct *curr, int cpu)
-{
-	struct perf_cpu_context *cpuctx;
-	struct perf_counter_context *ctx;
-
-	if (!atomic_read(&nr_counters))
-		return;
-
-	cpuctx = &per_cpu(perf_cpu_context, cpu);
-	ctx = curr->perf_counter_ctxp;
-
-	perf_ctx_adjust_freq(&cpuctx->ctx);
-	if (ctx)
-		perf_ctx_adjust_freq(ctx);
-
-	perf_counter_cpu_sched_out(cpuctx);
-	if (ctx)
-		__perf_counter_task_sched_out(ctx);
-
-	rotate_ctx(&cpuctx->ctx);
-	if (ctx)
-		rotate_ctx(ctx);
-
-	perf_counter_cpu_sched_in(cpuctx, cpu);
-	if (ctx)
-		perf_counter_task_sched_in(curr, cpu);
-}
-
-/*
- * Enable all of a task's counters that have been marked enable-on-exec.
- * This expects task == current.
- */
-static void perf_counter_enable_on_exec(struct task_struct *task)
-{
-	struct perf_counter_context *ctx;
-	struct perf_counter *counter;
-	unsigned long flags;
-	int enabled = 0;
-
-	local_irq_save(flags);
-	ctx = task->perf_counter_ctxp;
-	if (!ctx || !ctx->nr_counters)
-		goto out;
-
-	__perf_counter_task_sched_out(ctx);
-
-	spin_lock(&ctx->lock);
-
-	list_for_each_entry(counter, &ctx->counter_list, list_entry) {
-		if (!counter->attr.enable_on_exec)
-			continue;
-		counter->attr.enable_on_exec = 0;
-		if (counter->state >= PERF_COUNTER_STATE_INACTIVE)
-			continue;
-		__perf_counter_mark_enabled(counter, ctx);
-		enabled = 1;
-	}
-
-	/*
-	 * Unclone this context if we enabled any counter.
-	 */
-	if (enabled)
-		unclone_ctx(ctx);
-
-	spin_unlock(&ctx->lock);
-
-	perf_counter_task_sched_in(task, smp_processor_id());
- out:
-	local_irq_restore(flags);
-}
-
-/*
- * Cross CPU call to read the hardware counter
- */
-static void __perf_counter_read(void *info)
-{
-	struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
-	struct perf_counter *counter = info;
-	struct perf_counter_context *ctx = counter->ctx;
-	unsigned long flags;
-
-	/*
-	 * If this is a task context, we need to check whether it is
-	 * the current task context of this cpu.  If not it has been
-	 * scheduled out before the smp call arrived.  In that case
-	 * counter->count would have been updated to a recent sample
-	 * when the counter was scheduled out.
-	 */
-	if (ctx->task && cpuctx->task_ctx != ctx)
-		return;
-
-	local_irq_save(flags);
-	if (ctx->is_active)
-		update_context_time(ctx);
-	counter->pmu->read(counter);
-	update_counter_times(counter);
-	local_irq_restore(flags);
-}
-
-static u64 perf_counter_read(struct perf_counter *counter)
-{
-	/*
-	 * If counter is enabled and currently active on a CPU, update the
-	 * value in the counter structure:
-	 */
-	if (counter->state == PERF_COUNTER_STATE_ACTIVE) {
-		smp_call_function_single(counter->oncpu,
-					 __perf_counter_read, counter, 1);
-	} else if (counter->state == PERF_COUNTER_STATE_INACTIVE) {
-		update_counter_times(counter);
-	}
-
-	return atomic64_read(&counter->count);
-}
-
-/*
- * Initialize the perf_counter context in a task_struct:
- */
-static void
-__perf_counter_init_context(struct perf_counter_context *ctx,
-			    struct task_struct *task)
-{
-	memset(ctx, 0, sizeof(*ctx));
-	spin_lock_init(&ctx->lock);
-	mutex_init(&ctx->mutex);
-	INIT_LIST_HEAD(&ctx->counter_list);
-	INIT_LIST_HEAD(&ctx->event_list);
-	atomic_set(&ctx->refcount, 1);
-	ctx->task = task;
-}
-
-static struct perf_counter_context *find_get_context(pid_t pid, int cpu)
-{
-	struct perf_counter_context *ctx;
-	struct perf_cpu_context *cpuctx;
-	struct task_struct *task;
-	unsigned long flags;
-	int err;
-
-	/*
-	 * If cpu is not a wildcard then this is a percpu counter:
-	 */
-	if (cpu != -1) {
-		/* Must be root to operate on a CPU counter: */
-		if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN))
-			return ERR_PTR(-EACCES);
-
-		if (cpu < 0 || cpu > num_possible_cpus())
-			return ERR_PTR(-EINVAL);
-
-		/*
-		 * We could be clever and allow to attach a counter to an
-		 * offline CPU and activate it when the CPU comes up, but
-		 * that's for later.
-		 */
-		if (!cpu_isset(cpu, cpu_online_map))
-			return ERR_PTR(-ENODEV);
-
-		cpuctx = &per_cpu(perf_cpu_context, cpu);
-		ctx = &cpuctx->ctx;
-		get_ctx(ctx);
-
-		return ctx;
-	}
-
-	rcu_read_lock();
-	if (!pid)
-		task = current;
-	else
-		task = find_task_by_vpid(pid);
-	if (task)
-		get_task_struct(task);
-	rcu_read_unlock();
-
-	if (!task)
-		return ERR_PTR(-ESRCH);
-
-	/*
-	 * Can't attach counters to a dying task.
-	 */
-	err = -ESRCH;
-	if (task->flags & PF_EXITING)
-		goto errout;
-
-	/* Reuse ptrace permission checks for now. */
-	err = -EACCES;
-	if (!ptrace_may_access(task, PTRACE_MODE_READ))
-		goto errout;
-
- retry:
-	ctx = perf_lock_task_context(task, &flags);
-	if (ctx) {
-		unclone_ctx(ctx);
-		spin_unlock_irqrestore(&ctx->lock, flags);
-	}
-
-	if (!ctx) {
-		ctx = kmalloc(sizeof(struct perf_counter_context), GFP_KERNEL);
-		err = -ENOMEM;
-		if (!ctx)
-			goto errout;
-		__perf_counter_init_context(ctx, task);
-		get_ctx(ctx);
-		if (cmpxchg(&task->perf_counter_ctxp, NULL, ctx)) {
-			/*
-			 * We raced with some other task; use
-			 * the context they set.
-			 */
-			kfree(ctx);
-			goto retry;
-		}
-		get_task_struct(task);
-	}
-
-	put_task_struct(task);
-	return ctx;
-
- errout:
-	put_task_struct(task);
-	return ERR_PTR(err);
-}
-
-static void free_counter_rcu(struct rcu_head *head)
-{
-	struct perf_counter *counter;
-
-	counter = container_of(head, struct perf_counter, rcu_head);
-	if (counter->ns)
-		put_pid_ns(counter->ns);
-	kfree(counter);
-}
-
-static void perf_pending_sync(struct perf_counter *counter);
-
-static void free_counter(struct perf_counter *counter)
-{
-	perf_pending_sync(counter);
-
-	if (!counter->parent) {
-		atomic_dec(&nr_counters);
-		if (counter->attr.mmap)
-			atomic_dec(&nr_mmap_counters);
-		if (counter->attr.comm)
-			atomic_dec(&nr_comm_counters);
-		if (counter->attr.task)
-			atomic_dec(&nr_task_counters);
-	}
-
-	if (counter->output) {
-		fput(counter->output->filp);
-		counter->output = NULL;
-	}
-
-	if (counter->destroy)
-		counter->destroy(counter);
-
-	put_ctx(counter->ctx);
-	call_rcu(&counter->rcu_head, free_counter_rcu);
-}
-
-/*
- * Called when the last reference to the file is gone.
- */
-static int perf_release(struct inode *inode, struct file *file)
-{
-	struct perf_counter *counter = file->private_data;
-	struct perf_counter_context *ctx = counter->ctx;
-
-	file->private_data = NULL;
-
-	WARN_ON_ONCE(ctx->parent_ctx);
-	mutex_lock(&ctx->mutex);
-	perf_counter_remove_from_context(counter);
-	mutex_unlock(&ctx->mutex);
-
-	mutex_lock(&counter->owner->perf_counter_mutex);
-	list_del_init(&counter->owner_entry);
-	mutex_unlock(&counter->owner->perf_counter_mutex);
-	put_task_struct(counter->owner);
-
-	free_counter(counter);
-
-	return 0;
-}
-
-static int perf_counter_read_size(struct perf_counter *counter)
-{
-	int entry = sizeof(u64); /* value */
-	int size = 0;
-	int nr = 1;
-
-	if (counter->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
-		size += sizeof(u64);
-
-	if (counter->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
-		size += sizeof(u64);
-
-	if (counter->attr.read_format & PERF_FORMAT_ID)
-		entry += sizeof(u64);
-
-	if (counter->attr.read_format & PERF_FORMAT_GROUP) {
-		nr += counter->group_leader->nr_siblings;
-		size += sizeof(u64);
-	}
-
-	size += entry * nr;
-
-	return size;
-}
-
-static u64 perf_counter_read_value(struct perf_counter *counter)
-{
-	struct perf_counter *child;
-	u64 total = 0;
-
-	total += perf_counter_read(counter);
-	list_for_each_entry(child, &counter->child_list, child_list)
-		total += perf_counter_read(child);
-
-	return total;
-}
-
-static int perf_counter_read_entry(struct perf_counter *counter,
-				   u64 read_format, char __user *buf)
-{
-	int n = 0, count = 0;
-	u64 values[2];
-
-	values[n++] = perf_counter_read_value(counter);
-	if (read_format & PERF_FORMAT_ID)
-		values[n++] = primary_counter_id(counter);
-
-	count = n * sizeof(u64);
-
-	if (copy_to_user(buf, values, count))
-		return -EFAULT;
-
-	return count;
-}
-
-static int perf_counter_read_group(struct perf_counter *counter,
-				   u64 read_format, char __user *buf)
-{
-	struct perf_counter *leader = counter->group_leader, *sub;
-	int n = 0, size = 0, err = -EFAULT;
-	u64 values[3];
-
-	values[n++] = 1 + leader->nr_siblings;
-	if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
-		values[n++] = leader->total_time_enabled +
-			atomic64_read(&leader->child_total_time_enabled);
-	}
-	if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
-		values[n++] = leader->total_time_running +
-			atomic64_read(&leader->child_total_time_running);
-	}
-
-	size = n * sizeof(u64);
-
-	if (copy_to_user(buf, values, size))
-		return -EFAULT;
-
-	err = perf_counter_read_entry(leader, read_format, buf + size);
-	if (err < 0)
-		return err;
-
-	size += err;
-
-	list_for_each_entry(sub, &leader->sibling_list, list_entry) {
-		err = perf_counter_read_entry(sub, read_format,
-				buf + size);
-		if (err < 0)
-			return err;
-
-		size += err;
-	}
-
-	return size;
-}
-
-static int perf_counter_read_one(struct perf_counter *counter,
-				 u64 read_format, char __user *buf)
-{
-	u64 values[4];
-	int n = 0;
-
-	values[n++] = perf_counter_read_value(counter);
-	if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
-		values[n++] = counter->total_time_enabled +
-			atomic64_read(&counter->child_total_time_enabled);
-	}
-	if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
-		values[n++] = counter->total_time_running +
-			atomic64_read(&counter->child_total_time_running);
-	}
-	if (read_format & PERF_FORMAT_ID)
-		values[n++] = primary_counter_id(counter);
-
-	if (copy_to_user(buf, values, n * sizeof(u64)))
-		return -EFAULT;
-
-	return n * sizeof(u64);
-}
-
-/*
- * Read the performance counter - simple non blocking version for now
- */
-static ssize_t
-perf_read_hw(struct perf_counter *counter, char __user *buf, size_t count)
-{
-	u64 read_format = counter->attr.read_format;
-	int ret;
-
-	/*
-	 * Return end-of-file for a read on a counter that is in
-	 * error state (i.e. because it was pinned but it couldn't be
-	 * scheduled on to the CPU at some point).
-	 */
-	if (counter->state == PERF_COUNTER_STATE_ERROR)
-		return 0;
-
-	if (count < perf_counter_read_size(counter))
-		return -ENOSPC;
-
-	WARN_ON_ONCE(counter->ctx->parent_ctx);
-	mutex_lock(&counter->child_mutex);
-	if (read_format & PERF_FORMAT_GROUP)
-		ret = perf_counter_read_group(counter, read_format, buf);
-	else
-		ret = perf_counter_read_one(counter, read_format, buf);
-	mutex_unlock(&counter->child_mutex);
-
-	return ret;
-}
-
-static ssize_t
-perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
-{
-	struct perf_counter *counter = file->private_data;
-
-	return perf_read_hw(counter, buf, count);
-}
-
-static unsigned int perf_poll(struct file *file, poll_table *wait)
-{
-	struct perf_counter *counter = file->private_data;
-	struct perf_mmap_data *data;
-	unsigned int events = POLL_HUP;
-
-	rcu_read_lock();
-	data = rcu_dereference(counter->data);
-	if (data)
-		events = atomic_xchg(&data->poll, 0);
-	rcu_read_unlock();
-
-	poll_wait(file, &counter->waitq, wait);
-
-	return events;
-}
-
-static void perf_counter_reset(struct perf_counter *counter)
-{
-	(void)perf_counter_read(counter);
-	atomic64_set(&counter->count, 0);
-	perf_counter_update_userpage(counter);
-}
-
-/*
- * Holding the top-level counter's child_mutex means that any
- * descendant process that has inherited this counter will block
- * in sync_child_counter if it goes to exit, thus satisfying the
- * task existence requirements of perf_counter_enable/disable.
- */
-static void perf_counter_for_each_child(struct perf_counter *counter,
-					void (*func)(struct perf_counter *))
-{
-	struct perf_counter *child;
-
-	WARN_ON_ONCE(counter->ctx->parent_ctx);
-	mutex_lock(&counter->child_mutex);
-	func(counter);
-	list_for_each_entry(child, &counter->child_list, child_list)
-		func(child);
-	mutex_unlock(&counter->child_mutex);
-}
-
-static void perf_counter_for_each(struct perf_counter *counter,
-				  void (*func)(struct perf_counter *))
-{
-	struct perf_counter_context *ctx = counter->ctx;
-	struct perf_counter *sibling;
-
-	WARN_ON_ONCE(ctx->parent_ctx);
-	mutex_lock(&ctx->mutex);
-	counter = counter->group_leader;
-
-	perf_counter_for_each_child(counter, func);
-	func(counter);
-	list_for_each_entry(sibling, &counter->sibling_list, list_entry)
-		perf_counter_for_each_child(counter, func);
-	mutex_unlock(&ctx->mutex);
-}
-
-static int perf_counter_period(struct perf_counter *counter, u64 __user *arg)
-{
-	struct perf_counter_context *ctx = counter->ctx;
-	unsigned long size;
-	int ret = 0;
-	u64 value;
-
-	if (!counter->attr.sample_period)
-		return -EINVAL;
-
-	size = copy_from_user(&value, arg, sizeof(value));
-	if (size != sizeof(value))
-		return -EFAULT;
-
-	if (!value)
-		return -EINVAL;
-
-	spin_lock_irq(&ctx->lock);
-	if (counter->attr.freq) {
-		if (value > sysctl_perf_counter_sample_rate) {
-			ret = -EINVAL;
-			goto unlock;
-		}
-
-		counter->attr.sample_freq = value;
-	} else {
-		counter->attr.sample_period = value;
-		counter->hw.sample_period = value;
-	}
-unlock:
-	spin_unlock_irq(&ctx->lock);
-
-	return ret;
-}
-
-int perf_counter_set_output(struct perf_counter *counter, int output_fd);
-
-static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
-{
-	struct perf_counter *counter = file->private_data;
-	void (*func)(struct perf_counter *);
-	u32 flags = arg;
-
-	switch (cmd) {
-	case PERF_COUNTER_IOC_ENABLE:
-		func = perf_counter_enable;
-		break;
-	case PERF_COUNTER_IOC_DISABLE:
-		func = perf_counter_disable;
-		break;
-	case PERF_COUNTER_IOC_RESET:
-		func = perf_counter_reset;
-		break;
-
-	case PERF_COUNTER_IOC_REFRESH:
-		return perf_counter_refresh(counter, arg);
-
-	case PERF_COUNTER_IOC_PERIOD:
-		return perf_counter_period(counter, (u64 __user *)arg);
-
-	case PERF_COUNTER_IOC_SET_OUTPUT:
-		return perf_counter_set_output(counter, arg);
-
-	default:
-		return -ENOTTY;
-	}
-
-	if (flags & PERF_IOC_FLAG_GROUP)
-		perf_counter_for_each(counter, func);
-	else
-		perf_counter_for_each_child(counter, func);
-
-	return 0;
-}
-
-int perf_counter_task_enable(void)
-{
-	struct perf_counter *counter;
-
-	mutex_lock(&current->perf_counter_mutex);
-	list_for_each_entry(counter, &current->perf_counter_list, owner_entry)
-		perf_counter_for_each_child(counter, perf_counter_enable);
-	mutex_unlock(&current->perf_counter_mutex);
-
-	return 0;
-}
-
-int perf_counter_task_disable(void)
-{
-	struct perf_counter *counter;
-
-	mutex_lock(&current->perf_counter_mutex);
-	list_for_each_entry(counter, &current->perf_counter_list, owner_entry)
-		perf_counter_for_each_child(counter, perf_counter_disable);
-	mutex_unlock(&current->perf_counter_mutex);
-
-	return 0;
-}
-
-#ifndef PERF_COUNTER_INDEX_OFFSET
-# define PERF_COUNTER_INDEX_OFFSET 0
-#endif
-
-static int perf_counter_index(struct perf_counter *counter)
-{
-	if (counter->state != PERF_COUNTER_STATE_ACTIVE)
-		return 0;
-
-	return counter->hw.idx + 1 - PERF_COUNTER_INDEX_OFFSET;
-}
-
-/*
- * Callers need to ensure there can be no nesting of this function, otherwise
- * the seqlock logic goes bad. We can not serialize this because the arch
- * code calls this from NMI context.
- */
-void perf_counter_update_userpage(struct perf_counter *counter)
-{
-	struct perf_counter_mmap_page *userpg;
-	struct perf_mmap_data *data;
-
-	rcu_read_lock();
-	data = rcu_dereference(counter->data);
-	if (!data)
-		goto unlock;
-
-	userpg = data->user_page;
-
-	/*
-	 * Disable preemption so as to not let the corresponding user-space
-	 * spin too long if we get preempted.
-	 */
-	preempt_disable();
-	++userpg->lock;
-	barrier();
-	userpg->index = perf_counter_index(counter);
-	userpg->offset = atomic64_read(&counter->count);
-	if (counter->state == PERF_COUNTER_STATE_ACTIVE)
-		userpg->offset -= atomic64_read(&counter->hw.prev_count);
-
-	userpg->time_enabled = counter->total_time_enabled +
-			atomic64_read(&counter->child_total_time_enabled);
-
-	userpg->time_running = counter->total_time_running +
-			atomic64_read(&counter->child_total_time_running);
-
-	barrier();
-	++userpg->lock;
-	preempt_enable();
-unlock:
-	rcu_read_unlock();
-}
-
-static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
-{
-	struct perf_counter *counter = vma->vm_file->private_data;
-	struct perf_mmap_data *data;
-	int ret = VM_FAULT_SIGBUS;
-
-	if (vmf->flags & FAULT_FLAG_MKWRITE) {
-		if (vmf->pgoff == 0)
-			ret = 0;
-		return ret;
-	}
-
-	rcu_read_lock();
-	data = rcu_dereference(counter->data);
-	if (!data)
-		goto unlock;
-
-	if (vmf->pgoff == 0) {
-		vmf->page = virt_to_page(data->user_page);
-	} else {
-		int nr = vmf->pgoff - 1;
-
-		if ((unsigned)nr > data->nr_pages)
-			goto unlock;
-
-		if (vmf->flags & FAULT_FLAG_WRITE)
-			goto unlock;
-
-		vmf->page = virt_to_page(data->data_pages[nr]);
-	}
-
-	get_page(vmf->page);
-	vmf->page->mapping = vma->vm_file->f_mapping;
-	vmf->page->index   = vmf->pgoff;
-
-	ret = 0;
-unlock:
-	rcu_read_unlock();
-
-	return ret;
-}
-
-static int perf_mmap_data_alloc(struct perf_counter *counter, int nr_pages)
-{
-	struct perf_mmap_data *data;
-	unsigned long size;
-	int i;
-
-	WARN_ON(atomic_read(&counter->mmap_count));
-
-	size = sizeof(struct perf_mmap_data);
-	size += nr_pages * sizeof(void *);
-
-	data = kzalloc(size, GFP_KERNEL);
-	if (!data)
-		goto fail;
-
-	data->user_page = (void *)get_zeroed_page(GFP_KERNEL);
-	if (!data->user_page)
-		goto fail_user_page;
-
-	for (i = 0; i < nr_pages; i++) {
-		data->data_pages[i] = (void *)get_zeroed_page(GFP_KERNEL);
-		if (!data->data_pages[i])
-			goto fail_data_pages;
-	}
-
-	data->nr_pages = nr_pages;
-	atomic_set(&data->lock, -1);
-
-	rcu_assign_pointer(counter->data, data);
-
-	return 0;
-
-fail_data_pages:
-	for (i--; i >= 0; i--)
-		free_page((unsigned long)data->data_pages[i]);
-
-	free_page((unsigned long)data->user_page);
-
-fail_user_page:
-	kfree(data);
-
-fail:
-	return -ENOMEM;
-}
-
-static void perf_mmap_free_page(unsigned long addr)
-{
-	struct page *page = virt_to_page((void *)addr);
-
-	page->mapping = NULL;
-	__free_page(page);
-}
-
-static void __perf_mmap_data_free(struct rcu_head *rcu_head)
-{
-	struct perf_mmap_data *data;
-	int i;
-
-	data = container_of(rcu_head, struct perf_mmap_data, rcu_head);
-
-	perf_mmap_free_page((unsigned long)data->user_page);
-	for (i = 0; i < data->nr_pages; i++)
-		perf_mmap_free_page((unsigned long)data->data_pages[i]);
-
-	kfree(data);
-}
-
-static void perf_mmap_data_free(struct perf_counter *counter)
-{
-	struct perf_mmap_data *data = counter->data;
-
-	WARN_ON(atomic_read(&counter->mmap_count));
-
-	rcu_assign_pointer(counter->data, NULL);
-	call_rcu(&data->rcu_head, __perf_mmap_data_free);
-}
-
-static void perf_mmap_open(struct vm_area_struct *vma)
-{
-	struct perf_counter *counter = vma->vm_file->private_data;
-
-	atomic_inc(&counter->mmap_count);
-}
-
-static void perf_mmap_close(struct vm_area_struct *vma)
-{
-	struct perf_counter *counter = vma->vm_file->private_data;
-
-	WARN_ON_ONCE(counter->ctx->parent_ctx);
-	if (atomic_dec_and_mutex_lock(&counter->mmap_count, &counter->mmap_mutex)) {
-		struct user_struct *user = current_user();
-
-		atomic_long_sub(counter->data->nr_pages + 1, &user->locked_vm);
-		vma->vm_mm->locked_vm -= counter->data->nr_locked;
-		perf_mmap_data_free(counter);
-		mutex_unlock(&counter->mmap_mutex);
-	}
-}
-
-static struct vm_operations_struct perf_mmap_vmops = {
-	.open		= perf_mmap_open,
-	.close		= perf_mmap_close,
-	.fault		= perf_mmap_fault,
-	.page_mkwrite	= perf_mmap_fault,
-};
-
-static int perf_mmap(struct file *file, struct vm_area_struct *vma)
-{
-	struct perf_counter *counter = file->private_data;
-	unsigned long user_locked, user_lock_limit;
-	struct user_struct *user = current_user();
-	unsigned long locked, lock_limit;
-	unsigned long vma_size;
-	unsigned long nr_pages;
-	long user_extra, extra;
-	int ret = 0;
-
-	if (!(vma->vm_flags & VM_SHARED))
-		return -EINVAL;
-
-	vma_size = vma->vm_end - vma->vm_start;
-	nr_pages = (vma_size / PAGE_SIZE) - 1;
-
-	/*
-	 * If we have data pages ensure they're a power-of-two number, so we
-	 * can do bitmasks instead of modulo.
-	 */
-	if (nr_pages != 0 && !is_power_of_2(nr_pages))
-		return -EINVAL;
-
-	if (vma_size != PAGE_SIZE * (1 + nr_pages))
-		return -EINVAL;
-
-	if (vma->vm_pgoff != 0)
-		return -EINVAL;
-
-	WARN_ON_ONCE(counter->ctx->parent_ctx);
-	mutex_lock(&counter->mmap_mutex);
-	if (counter->output) {
-		ret = -EINVAL;
-		goto unlock;
-	}
-
-	if (atomic_inc_not_zero(&counter->mmap_count)) {
-		if (nr_pages != counter->data->nr_pages)
-			ret = -EINVAL;
-		goto unlock;
-	}
-
-	user_extra = nr_pages + 1;
-	user_lock_limit = sysctl_perf_counter_mlock >> (PAGE_SHIFT - 10);
-
-	/*
-	 * Increase the limit linearly with more CPUs:
-	 */
-	user_lock_limit *= num_online_cpus();
-
-	user_locked = atomic_long_read(&user->locked_vm) + user_extra;
-
-	extra = 0;
-	if (user_locked > user_lock_limit)
-		extra = user_locked - user_lock_limit;
-
-	lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
-	lock_limit >>= PAGE_SHIFT;
-	locked = vma->vm_mm->locked_vm + extra;
-
-	if ((locked > lock_limit) && !capable(CAP_IPC_LOCK)) {
-		ret = -EPERM;
-		goto unlock;
-	}
-
-	WARN_ON(counter->data);
-	ret = perf_mmap_data_alloc(counter, nr_pages);
-	if (ret)
-		goto unlock;
-
-	atomic_set(&counter->mmap_count, 1);
-	atomic_long_add(user_extra, &user->locked_vm);
-	vma->vm_mm->locked_vm += extra;
-	counter->data->nr_locked = extra;
-	if (vma->vm_flags & VM_WRITE)
-		counter->data->writable = 1;
-
-unlock:
-	mutex_unlock(&counter->mmap_mutex);
-
-	vma->vm_flags |= VM_RESERVED;
-	vma->vm_ops = &perf_mmap_vmops;
-
-	return ret;
-}
-
-static int perf_fasync(int fd, struct file *filp, int on)
-{
-	struct inode *inode = filp->f_path.dentry->d_inode;
-	struct perf_counter *counter = filp->private_data;
-	int retval;
-
-	mutex_lock(&inode->i_mutex);
-	retval = fasync_helper(fd, filp, on, &counter->fasync);
-	mutex_unlock(&inode->i_mutex);
-
-	if (retval < 0)
-		return retval;
-
-	return 0;
-}
-
-static const struct file_operations perf_fops = {
-	.release		= perf_release,
-	.read			= perf_read,
-	.poll			= perf_poll,
-	.unlocked_ioctl		= perf_ioctl,
-	.compat_ioctl		= perf_ioctl,
-	.mmap			= perf_mmap,
-	.fasync			= perf_fasync,
-};
-
-/*
- * Perf counter wakeup
- *
- * If there's data, ensure we set the poll() state and publish everything
- * to user-space before waking everybody up.
- */
-
-void perf_counter_wakeup(struct perf_counter *counter)
-{
-	wake_up_all(&counter->waitq);
-
-	if (counter->pending_kill) {
-		kill_fasync(&counter->fasync, SIGIO, counter->pending_kill);
-		counter->pending_kill = 0;
-	}
-}
-
-/*
- * Pending wakeups
- *
- * Handle the case where we need to wakeup up from NMI (or rq->lock) context.
- *
- * The NMI bit means we cannot possibly take locks. Therefore, maintain a
- * single linked list and use cmpxchg() to add entries lockless.
- */
-
-static void perf_pending_counter(struct perf_pending_entry *entry)
-{
-	struct perf_counter *counter = container_of(entry,
-			struct perf_counter, pending);
-
-	if (counter->pending_disable) {
-		counter->pending_disable = 0;
-		__perf_counter_disable(counter);
-	}
-
-	if (counter->pending_wakeup) {
-		counter->pending_wakeup = 0;
-		perf_counter_wakeup(counter);
-	}
-}
-
-#define PENDING_TAIL ((struct perf_pending_entry *)-1UL)
-
-static DEFINE_PER_CPU(struct perf_pending_entry *, perf_pending_head) = {
-	PENDING_TAIL,
-};
-
-static void perf_pending_queue(struct perf_pending_entry *entry,
-			       void (*func)(struct perf_pending_entry *))
-{
-	struct perf_pending_entry **head;
-
-	if (cmpxchg(&entry->next, NULL, PENDING_TAIL) != NULL)
-		return;
-
-	entry->func = func;
-
-	head = &get_cpu_var(perf_pending_head);
-
-	do {
-		entry->next = *head;
-	} while (cmpxchg(head, entry->next, entry) != entry->next);
-
-	set_perf_counter_pending();
-
-	put_cpu_var(perf_pending_head);
-}
-
-static int __perf_pending_run(void)
-{
-	struct perf_pending_entry *list;
-	int nr = 0;
-
-	list = xchg(&__get_cpu_var(perf_pending_head), PENDING_TAIL);
-	while (list != PENDING_TAIL) {
-		void (*func)(struct perf_pending_entry *);
-		struct perf_pending_entry *entry = list;
-
-		list = list->next;
-
-		func = entry->func;
-		entry->next = NULL;
-		/*
-		 * Ensure we observe the unqueue before we issue the wakeup,
-		 * so that we won't be waiting forever.
-		 * -- see perf_not_pending().
-		 */
-		smp_wmb();
-
-		func(entry);
-		nr++;
-	}
-
-	return nr;
-}
-
-static inline int perf_not_pending(struct perf_counter *counter)
-{
-	/*
-	 * If we flush on whatever cpu we run, there is a chance we don't
-	 * need to wait.
-	 */
-	get_cpu();
-	__perf_pending_run();
-	put_cpu();
-
-	/*
-	 * Ensure we see the proper queue state before going to sleep
-	 * so that we do not miss the wakeup. -- see perf_pending_handle()
-	 */
-	smp_rmb();
-	return counter->pending.next == NULL;
-}
-
-static void perf_pending_sync(struct perf_counter *counter)
-{
-	wait_event(counter->waitq, perf_not_pending(counter));
-}
-
-void perf_counter_do_pending(void)
-{
-	__perf_pending_run();
-}
-
-/*
- * Callchain support -- arch specific
- */
-
-__weak struct perf_callchain_entry *perf_callchain(struct pt_regs *regs)
-{
-	return NULL;
-}
-
-/*
- * Output
- */
-
-struct perf_output_handle {
-	struct perf_counter	*counter;
-	struct perf_mmap_data	*data;
-	unsigned long		head;
-	unsigned long		offset;
-	int			nmi;
-	int			sample;
-	int			locked;
-	unsigned long		flags;
-};
-
-static bool perf_output_space(struct perf_mmap_data *data,
-			      unsigned int offset, unsigned int head)
-{
-	unsigned long tail;
-	unsigned long mask;
-
-	if (!data->writable)
-		return true;
-
-	mask = (data->nr_pages << PAGE_SHIFT) - 1;
-	/*
-	 * Userspace could choose to issue a mb() before updating the tail
-	 * pointer. So that all reads will be completed before the write is
-	 * issued.
-	 */
-	tail = ACCESS_ONCE(data->user_page->data_tail);
-	smp_rmb();
-
-	offset = (offset - tail) & mask;
-	head   = (head   - tail) & mask;
-
-	if ((int)(head - offset) < 0)
-		return false;
-
-	return true;
-}
-
-static void perf_output_wakeup(struct perf_output_handle *handle)
-{
-	atomic_set(&handle->data->poll, POLL_IN);
-
-	if (handle->nmi) {
-		handle->counter->pending_wakeup = 1;
-		perf_pending_queue(&handle->counter->pending,
-				   perf_pending_counter);
-	} else
-		perf_counter_wakeup(handle->counter);
-}
-
-/*
- * Curious locking construct.
- *
- * We need to ensure a later event doesn't publish a head when a former
- * event isn't done writing. However since we need to deal with NMIs we
- * cannot fully serialize things.
- *
- * What we do is serialize between CPUs so we only have to deal with NMI
- * nesting on a single CPU.
- *
- * We only publish the head (and generate a wakeup) when the outer-most
- * event completes.
- */
-static void perf_output_lock(struct perf_output_handle *handle)
-{
-	struct perf_mmap_data *data = handle->data;
-	int cpu;
-
-	handle->locked = 0;
-
-	local_irq_save(handle->flags);
-	cpu = smp_processor_id();
-
-	if (in_nmi() && atomic_read(&data->lock) == cpu)
-		return;
-
-	while (atomic_cmpxchg(&data->lock, -1, cpu) != -1)
-		cpu_relax();
-
-	handle->locked = 1;
-}
-
-static void perf_output_unlock(struct perf_output_handle *handle)
-{
-	struct perf_mmap_data *data = handle->data;
-	unsigned long head;
-	int cpu;
-
-	data->done_head = data->head;
-
-	if (!handle->locked)
-		goto out;
-
-again:
-	/*
-	 * The xchg implies a full barrier that ensures all writes are done
-	 * before we publish the new head, matched by a rmb() in userspace when
-	 * reading this position.
-	 */
-	while ((head = atomic_long_xchg(&data->done_head, 0)))
-		data->user_page->data_head = head;
-
-	/*
-	 * NMI can happen here, which means we can miss a done_head update.
-	 */
-
-	cpu = atomic_xchg(&data->lock, -1);
-	WARN_ON_ONCE(cpu != smp_processor_id());
-
-	/*
-	 * Therefore we have to validate we did not indeed do so.
-	 */
-	if (unlikely(atomic_long_read(&data->done_head))) {
-		/*
-		 * Since we had it locked, we can lock it again.
-		 */
-		while (atomic_cmpxchg(&data->lock, -1, cpu) != -1)
-			cpu_relax();
-
-		goto again;
-	}
-
-	if (atomic_xchg(&data->wakeup, 0))
-		perf_output_wakeup(handle);
-out:
-	local_irq_restore(handle->flags);
-}
-
-static void perf_output_copy(struct perf_output_handle *handle,
-			     const void *buf, unsigned int len)
-{
-	unsigned int pages_mask;
-	unsigned int offset;
-	unsigned int size;
-	void **pages;
-
-	offset		= handle->offset;
-	pages_mask	= handle->data->nr_pages - 1;
-	pages		= handle->data->data_pages;
-
-	do {
-		unsigned int page_offset;
-		int nr;
-
-		nr	    = (offset >> PAGE_SHIFT) & pages_mask;
-		page_offset = offset & (PAGE_SIZE - 1);
-		size	    = min_t(unsigned int, PAGE_SIZE - page_offset, len);
-
-		memcpy(pages[nr] + page_offset, buf, size);
-
-		len	    -= size;
-		buf	    += size;
-		offset	    += size;
-	} while (len);
-
-	handle->offset = offset;
-
-	/*
-	 * Check we didn't copy past our reservation window, taking the
-	 * possible unsigned int wrap into account.
-	 */
-	WARN_ON_ONCE(((long)(handle->head - handle->offset)) < 0);
-}
-
-#define perf_output_put(handle, x) \
-	perf_output_copy((handle), &(x), sizeof(x))
-
-static int perf_output_begin(struct perf_output_handle *handle,
-			     struct perf_counter *counter, unsigned int size,
-			     int nmi, int sample)
-{
-	struct perf_counter *output_counter;
-	struct perf_mmap_data *data;
-	unsigned int offset, head;
-	int have_lost;
-	struct {
-		struct perf_event_header header;
-		u64			 id;
-		u64			 lost;
-	} lost_event;
-
-	rcu_read_lock();
-	/*
-	 * For inherited counters we send all the output towards the parent.
-	 */
-	if (counter->parent)
-		counter = counter->parent;
-
-	output_counter = rcu_dereference(counter->output);
-	if (output_counter)
-		counter = output_counter;
-
-	data = rcu_dereference(counter->data);
-	if (!data)
-		goto out;
-
-	handle->data	= data;
-	handle->counter	= counter;
-	handle->nmi	= nmi;
-	handle->sample	= sample;
-
-	if (!data->nr_pages)
-		goto fail;
-
-	have_lost = atomic_read(&data->lost);
-	if (have_lost)
-		size += sizeof(lost_event);
-
-	perf_output_lock(handle);
-
-	do {
-		offset = head = atomic_long_read(&data->head);
-		head += size;
-		if (unlikely(!perf_output_space(data, offset, head)))
-			goto fail;
-	} while (atomic_long_cmpxchg(&data->head, offset, head) != offset);
-
-	handle->offset	= offset;
-	handle->head	= head;
-
-	if ((offset >> PAGE_SHIFT) != (head >> PAGE_SHIFT))
-		atomic_set(&data->wakeup, 1);
-
-	if (have_lost) {
-		lost_event.header.type = PERF_EVENT_LOST;
-		lost_event.header.misc = 0;
-		lost_event.header.size = sizeof(lost_event);
-		lost_event.id          = counter->id;
-		lost_event.lost        = atomic_xchg(&data->lost, 0);
-
-		perf_output_put(handle, lost_event);
-	}
-
-	return 0;
-
-fail:
-	atomic_inc(&data->lost);
-	perf_output_unlock(handle);
-out:
-	rcu_read_unlock();
-
-	return -ENOSPC;
-}
-
-static void perf_output_end(struct perf_output_handle *handle)
-{
-	struct perf_counter *counter = handle->counter;
-	struct perf_mmap_data *data = handle->data;
-
-	int wakeup_events = counter->attr.wakeup_events;
-
-	if (handle->sample && wakeup_events) {
-		int events = atomic_inc_return(&data->events);
-		if (events >= wakeup_events) {
-			atomic_sub(wakeup_events, &data->events);
-			atomic_set(&data->wakeup, 1);
-		}
-	}
-
-	perf_output_unlock(handle);
-	rcu_read_unlock();
-}
-
-static u32 perf_counter_pid(struct perf_counter *counter, struct task_struct *p)
-{
-	/*
-	 * only top level counters have the pid namespace they were created in
-	 */
-	if (counter->parent)
-		counter = counter->parent;
-
-	return task_tgid_nr_ns(p, counter->ns);
-}
-
-static u32 perf_counter_tid(struct perf_counter *counter, struct task_struct *p)
-{
-	/*
-	 * only top level counters have the pid namespace they were created in
-	 */
-	if (counter->parent)
-		counter = counter->parent;
-
-	return task_pid_nr_ns(p, counter->ns);
-}
-
-static void perf_output_read_one(struct perf_output_handle *handle,
-				 struct perf_counter *counter)
-{
-	u64 read_format = counter->attr.read_format;
-	u64 values[4];
-	int n = 0;
-
-	values[n++] = atomic64_read(&counter->count);
-	if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
-		values[n++] = counter->total_time_enabled +
-			atomic64_read(&counter->child_total_time_enabled);
-	}
-	if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
-		values[n++] = counter->total_time_running +
-			atomic64_read(&counter->child_total_time_running);
-	}
-	if (read_format & PERF_FORMAT_ID)
-		values[n++] = primary_counter_id(counter);
-
-	perf_output_copy(handle, values, n * sizeof(u64));
-}
-
-/*
- * XXX PERF_FORMAT_GROUP vs inherited counters seems difficult.
- */
-static void perf_output_read_group(struct perf_output_handle *handle,
-			    struct perf_counter *counter)
-{
-	struct perf_counter *leader = counter->group_leader, *sub;
-	u64 read_format = counter->attr.read_format;
-	u64 values[5];
-	int n = 0;
-
-	values[n++] = 1 + leader->nr_siblings;
-
-	if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
-		values[n++] = leader->total_time_enabled;
-
-	if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
-		values[n++] = leader->total_time_running;
-
-	if (leader != counter)
-		leader->pmu->read(leader);
-
-	values[n++] = atomic64_read(&leader->count);
-	if (read_format & PERF_FORMAT_ID)
-		values[n++] = primary_counter_id(leader);
-
-	perf_output_copy(handle, values, n * sizeof(u64));
-
-	list_for_each_entry(sub, &leader->sibling_list, list_entry) {
-		n = 0;
-
-		if (sub != counter)
-			sub->pmu->read(sub);
-
-		values[n++] = atomic64_read(&sub->count);
-		if (read_format & PERF_FORMAT_ID)
-			values[n++] = primary_counter_id(sub);
-
-		perf_output_copy(handle, values, n * sizeof(u64));
-	}
-}
-
-static void perf_output_read(struct perf_output_handle *handle,
-			     struct perf_counter *counter)
-{
-	if (counter->attr.read_format & PERF_FORMAT_GROUP)
-		perf_output_read_group(handle, counter);
-	else
-		perf_output_read_one(handle, counter);
-}
-
-void perf_counter_output(struct perf_counter *counter, int nmi,
-				struct perf_sample_data *data)
-{
-	int ret;
-	u64 sample_type = counter->attr.sample_type;
-	struct perf_output_handle handle;
-	struct perf_event_header header;
-	u64 ip;
-	struct {
-		u32 pid, tid;
-	} tid_entry;
-	struct perf_callchain_entry *callchain = NULL;
-	int callchain_size = 0;
-	u64 time;
-	struct {
-		u32 cpu, reserved;
-	} cpu_entry;
-
-	header.type = PERF_EVENT_SAMPLE;
-	header.size = sizeof(header);
-
-	header.misc = 0;
-	header.misc |= perf_misc_flags(data->regs);
-
-	if (sample_type & PERF_SAMPLE_IP) {
-		ip = perf_instruction_pointer(data->regs);
-		header.size += sizeof(ip);
-	}
-
-	if (sample_type & PERF_SAMPLE_TID) {
-		/* namespace issues */
-		tid_entry.pid = perf_counter_pid(counter, current);
-		tid_entry.tid = perf_counter_tid(counter, current);
-
-		header.size += sizeof(tid_entry);
-	}
-
-	if (sample_type & PERF_SAMPLE_TIME) {
-		/*
-		 * Maybe do better on x86 and provide cpu_clock_nmi()
-		 */
-		time = sched_clock();
-
-		header.size += sizeof(u64);
-	}
-
-	if (sample_type & PERF_SAMPLE_ADDR)
-		header.size += sizeof(u64);
-
-	if (sample_type & PERF_SAMPLE_ID)
-		header.size += sizeof(u64);
-
-	if (sample_type & PERF_SAMPLE_STREAM_ID)
-		header.size += sizeof(u64);
-
-	if (sample_type & PERF_SAMPLE_CPU) {
-		header.size += sizeof(cpu_entry);
-
-		cpu_entry.cpu = raw_smp_processor_id();
-		cpu_entry.reserved = 0;
-	}
-
-	if (sample_type & PERF_SAMPLE_PERIOD)
-		header.size += sizeof(u64);
-
-	if (sample_type & PERF_SAMPLE_READ)
-		header.size += perf_counter_read_size(counter);
-
-	if (sample_type & PERF_SAMPLE_CALLCHAIN) {
-		callchain = perf_callchain(data->regs);
-
-		if (callchain) {
-			callchain_size = (1 + callchain->nr) * sizeof(u64);
-			header.size += callchain_size;
-		} else
-			header.size += sizeof(u64);
-	}
-
-	if (sample_type & PERF_SAMPLE_RAW) {
-		int size = sizeof(u32);
-
-		if (data->raw)
-			size += data->raw->size;
-		else
-			size += sizeof(u32);
-
-		WARN_ON_ONCE(size & (sizeof(u64)-1));
-		header.size += size;
-	}
-
-	ret = perf_output_begin(&handle, counter, header.size, nmi, 1);
-	if (ret)
-		return;
-
-	perf_output_put(&handle, header);
-
-	if (sample_type & PERF_SAMPLE_IP)
-		perf_output_put(&handle, ip);
-
-	if (sample_type & PERF_SAMPLE_TID)
-		perf_output_put(&handle, tid_entry);
-
-	if (sample_type & PERF_SAMPLE_TIME)
-		perf_output_put(&handle, time);
-
-	if (sample_type & PERF_SAMPLE_ADDR)
-		perf_output_put(&handle, data->addr);
-
-	if (sample_type & PERF_SAMPLE_ID) {
-		u64 id = primary_counter_id(counter);
-
-		perf_output_put(&handle, id);
-	}
-
-	if (sample_type & PERF_SAMPLE_STREAM_ID)
-		perf_output_put(&handle, counter->id);
-
-	if (sample_type & PERF_SAMPLE_CPU)
-		perf_output_put(&handle, cpu_entry);
-
-	if (sample_type & PERF_SAMPLE_PERIOD)
-		perf_output_put(&handle, data->period);
-
-	if (sample_type & PERF_SAMPLE_READ)
-		perf_output_read(&handle, counter);
-
-	if (sample_type & PERF_SAMPLE_CALLCHAIN) {
-		if (callchain)
-			perf_output_copy(&handle, callchain, callchain_size);
-		else {
-			u64 nr = 0;
-			perf_output_put(&handle, nr);
-		}
-	}
-
-	if (sample_type & PERF_SAMPLE_RAW) {
-		if (data->raw) {
-			perf_output_put(&handle, data->raw->size);
-			perf_output_copy(&handle, data->raw->data, data->raw->size);
-		} else {
-			struct {
-				u32	size;
-				u32	data;
-			} raw = {
-				.size = sizeof(u32),
-				.data = 0,
-			};
-			perf_output_put(&handle, raw);
-		}
-	}
-
-	perf_output_end(&handle);
-}
-
-/*
- * read event
- */
-
-struct perf_read_event {
-	struct perf_event_header	header;
-
-	u32				pid;
-	u32				tid;
-};
-
-static void
-perf_counter_read_event(struct perf_counter *counter,
-			struct task_struct *task)
-{
-	struct perf_output_handle handle;
-	struct perf_read_event event = {
-		.header = {
-			.type = PERF_EVENT_READ,
-			.misc = 0,
-			.size = sizeof(event) + perf_counter_read_size(counter),
-		},
-		.pid = perf_counter_pid(counter, task),
-		.tid = perf_counter_tid(counter, task),
-	};
-	int ret;
-
-	ret = perf_output_begin(&handle, counter, event.header.size, 0, 0);
-	if (ret)
-		return;
-
-	perf_output_put(&handle, event);
-	perf_output_read(&handle, counter);
-
-	perf_output_end(&handle);
-}
-
-/*
- * task tracking -- fork/exit
- *
- * enabled by: attr.comm | attr.mmap | attr.task
- */
-
-struct perf_task_event {
-	struct task_struct		*task;
-	struct perf_counter_context	*task_ctx;
-
-	struct {
-		struct perf_event_header	header;
-
-		u32				pid;
-		u32				ppid;
-		u32				tid;
-		u32				ptid;
-	} event;
-};
-
-static void perf_counter_task_output(struct perf_counter *counter,
-				     struct perf_task_event *task_event)
-{
-	struct perf_output_handle handle;
-	int size = task_event->event.header.size;
-	struct task_struct *task = task_event->task;
-	int ret = perf_output_begin(&handle, counter, size, 0, 0);
-
-	if (ret)
-		return;
-
-	task_event->event.pid = perf_counter_pid(counter, task);
-	task_event->event.ppid = perf_counter_pid(counter, current);
-
-	task_event->event.tid = perf_counter_tid(counter, task);
-	task_event->event.ptid = perf_counter_tid(counter, current);
-
-	perf_output_put(&handle, task_event->event);
-	perf_output_end(&handle);
-}
-
-static int perf_counter_task_match(struct perf_counter *counter)
-{
-	if (counter->attr.comm || counter->attr.mmap || counter->attr.task)
-		return 1;
-
-	return 0;
-}
-
-static void perf_counter_task_ctx(struct perf_counter_context *ctx,
-				  struct perf_task_event *task_event)
-{
-	struct perf_counter *counter;
-
-	if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list))
-		return;
-
-	rcu_read_lock();
-	list_for_each_entry_rcu(counter, &ctx->event_list, event_entry) {
-		if (perf_counter_task_match(counter))
-			perf_counter_task_output(counter, task_event);
-	}
-	rcu_read_unlock();
-}
-
-static void perf_counter_task_event(struct perf_task_event *task_event)
-{
-	struct perf_cpu_context *cpuctx;
-	struct perf_counter_context *ctx = task_event->task_ctx;
-
-	cpuctx = &get_cpu_var(perf_cpu_context);
-	perf_counter_task_ctx(&cpuctx->ctx, task_event);
-	put_cpu_var(perf_cpu_context);
-
-	rcu_read_lock();
-	if (!ctx)
-		ctx = rcu_dereference(task_event->task->perf_counter_ctxp);
-	if (ctx)
-		perf_counter_task_ctx(ctx, task_event);
-	rcu_read_unlock();
-}
-
-static void perf_counter_task(struct task_struct *task,
-			      struct perf_counter_context *task_ctx,
-			      int new)
-{
-	struct perf_task_event task_event;
-
-	if (!atomic_read(&nr_comm_counters) &&
-	    !atomic_read(&nr_mmap_counters) &&
-	    !atomic_read(&nr_task_counters))
-		return;
-
-	task_event = (struct perf_task_event){
-		.task	  = task,
-		.task_ctx = task_ctx,
-		.event    = {
-			.header = {
-				.type = new ? PERF_EVENT_FORK : PERF_EVENT_EXIT,
-				.misc = 0,
-				.size = sizeof(task_event.event),
-			},
-			/* .pid  */
-			/* .ppid */
-			/* .tid  */
-			/* .ptid */
-		},
-	};
-
-	perf_counter_task_event(&task_event);
-}
-
-void perf_counter_fork(struct task_struct *task)
-{
-	perf_counter_task(task, NULL, 1);
-}
-
-/*
- * comm tracking
- */
-
-struct perf_comm_event {
-	struct task_struct	*task;
-	char			*comm;
-	int			comm_size;
-
-	struct {
-		struct perf_event_header	header;
-
-		u32				pid;
-		u32				tid;
-	} event;
-};
-
-static void perf_counter_comm_output(struct perf_counter *counter,
-				     struct perf_comm_event *comm_event)
-{
-	struct perf_output_handle handle;
-	int size = comm_event->event.header.size;
-	int ret = perf_output_begin(&handle, counter, size, 0, 0);
-
-	if (ret)
-		return;
-
-	comm_event->event.pid = perf_counter_pid(counter, comm_event->task);
-	comm_event->event.tid = perf_counter_tid(counter, comm_event->task);
-
-	perf_output_put(&handle, comm_event->event);
-	perf_output_copy(&handle, comm_event->comm,
-				   comm_event->comm_size);
-	perf_output_end(&handle);
-}
-
-static int perf_counter_comm_match(struct perf_counter *counter)
-{
-	if (counter->attr.comm)
-		return 1;
-
-	return 0;
-}
-
-static void perf_counter_comm_ctx(struct perf_counter_context *ctx,
-				  struct perf_comm_event *comm_event)
-{
-	struct perf_counter *counter;
-
-	if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list))
-		return;
-
-	rcu_read_lock();
-	list_for_each_entry_rcu(counter, &ctx->event_list, event_entry) {
-		if (perf_counter_comm_match(counter))
-			perf_counter_comm_output(counter, comm_event);
-	}
-	rcu_read_unlock();
-}
-
-static void perf_counter_comm_event(struct perf_comm_event *comm_event)
-{
-	struct perf_cpu_context *cpuctx;
-	struct perf_counter_context *ctx;
-	unsigned int size;
-	char comm[TASK_COMM_LEN];
-
-	memset(comm, 0, sizeof(comm));
-	strncpy(comm, comm_event->task->comm, sizeof(comm));
-	size = ALIGN(strlen(comm)+1, sizeof(u64));
-
-	comm_event->comm = comm;
-	comm_event->comm_size = size;
-
-	comm_event->event.header.size = sizeof(comm_event->event) + size;
-
-	cpuctx = &get_cpu_var(perf_cpu_context);
-	perf_counter_comm_ctx(&cpuctx->ctx, comm_event);
-	put_cpu_var(perf_cpu_context);
-
-	rcu_read_lock();
-	/*
-	 * doesn't really matter which of the child contexts the
-	 * events ends up in.
-	 */
-	ctx = rcu_dereference(current->perf_counter_ctxp);
-	if (ctx)
-		perf_counter_comm_ctx(ctx, comm_event);
-	rcu_read_unlock();
-}
-
-void perf_counter_comm(struct task_struct *task)
-{
-	struct perf_comm_event comm_event;
-
-	if (task->perf_counter_ctxp)
-		perf_counter_enable_on_exec(task);
-
-	if (!atomic_read(&nr_comm_counters))
-		return;
-
-	comm_event = (struct perf_comm_event){
-		.task	= task,
-		/* .comm      */
-		/* .comm_size */
-		.event  = {
-			.header = {
-				.type = PERF_EVENT_COMM,
-				.misc = 0,
-				/* .size */
-			},
-			/* .pid */
-			/* .tid */
-		},
-	};
-
-	perf_counter_comm_event(&comm_event);
-}
-
-/*
- * mmap tracking
- */
-
-struct perf_mmap_event {
-	struct vm_area_struct	*vma;
-
-	const char		*file_name;
-	int			file_size;
-
-	struct {
-		struct perf_event_header	header;
-
-		u32				pid;
-		u32				tid;
-		u64				start;
-		u64				len;
-		u64				pgoff;
-	} event;
-};
-
-static void perf_counter_mmap_output(struct perf_counter *counter,
-				     struct perf_mmap_event *mmap_event)
-{
-	struct perf_output_handle handle;
-	int size = mmap_event->event.header.size;
-	int ret = perf_output_begin(&handle, counter, size, 0, 0);
-
-	if (ret)
-		return;
-
-	mmap_event->event.pid = perf_counter_pid(counter, current);
-	mmap_event->event.tid = perf_counter_tid(counter, current);
-
-	perf_output_put(&handle, mmap_event->event);
-	perf_output_copy(&handle, mmap_event->file_name,
-				   mmap_event->file_size);
-	perf_output_end(&handle);
-}
-
-static int perf_counter_mmap_match(struct perf_counter *counter,
-				   struct perf_mmap_event *mmap_event)
-{
-	if (counter->attr.mmap)
-		return 1;
-
-	return 0;
-}
-
-static void perf_counter_mmap_ctx(struct perf_counter_context *ctx,
-				  struct perf_mmap_event *mmap_event)
-{
-	struct perf_counter *counter;
-
-	if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list))
-		return;
-
-	rcu_read_lock();
-	list_for_each_entry_rcu(counter, &ctx->event_list, event_entry) {
-		if (perf_counter_mmap_match(counter, mmap_event))
-			perf_counter_mmap_output(counter, mmap_event);
-	}
-	rcu_read_unlock();
-}
-
-static void perf_counter_mmap_event(struct perf_mmap_event *mmap_event)
-{
-	struct perf_cpu_context *cpuctx;
-	struct perf_counter_context *ctx;
-	struct vm_area_struct *vma = mmap_event->vma;
-	struct file *file = vma->vm_file;
-	unsigned int size;
-	char tmp[16];
-	char *buf = NULL;
-	const char *name;
-
-	memset(tmp, 0, sizeof(tmp));
-
-	if (file) {
-		/*
-		 * d_path works from the end of the buffer backwards, so we
-		 * need to add enough zero bytes after the string to handle
-		 * the 64bit alignment we do later.
-		 */
-		buf = kzalloc(PATH_MAX + sizeof(u64), GFP_KERNEL);
-		if (!buf) {
-			name = strncpy(tmp, "//enomem", sizeof(tmp));
-			goto got_name;
-		}
-		name = d_path(&file->f_path, buf, PATH_MAX);
-		if (IS_ERR(name)) {
-			name = strncpy(tmp, "//toolong", sizeof(tmp));
-			goto got_name;
-		}
-	} else {
-		if (arch_vma_name(mmap_event->vma)) {
-			name = strncpy(tmp, arch_vma_name(mmap_event->vma),
-				       sizeof(tmp));
-			goto got_name;
-		}
-
-		if (!vma->vm_mm) {
-			name = strncpy(tmp, "[vdso]", sizeof(tmp));
-			goto got_name;
-		}
-
-		name = strncpy(tmp, "//anon", sizeof(tmp));
-		goto got_name;
-	}
-
-got_name:
-	size = ALIGN(strlen(name)+1, sizeof(u64));
-
-	mmap_event->file_name = name;
-	mmap_event->file_size = size;
-
-	mmap_event->event.header.size = sizeof(mmap_event->event) + size;
-
-	cpuctx = &get_cpu_var(perf_cpu_context);
-	perf_counter_mmap_ctx(&cpuctx->ctx, mmap_event);
-	put_cpu_var(perf_cpu_context);
-
-	rcu_read_lock();
-	/*
-	 * doesn't really matter which of the child contexts the
-	 * events ends up in.
-	 */
-	ctx = rcu_dereference(current->perf_counter_ctxp);
-	if (ctx)
-		perf_counter_mmap_ctx(ctx, mmap_event);
-	rcu_read_unlock();
-
-	kfree(buf);
-}
-
-void __perf_counter_mmap(struct vm_area_struct *vma)
-{
-	struct perf_mmap_event mmap_event;
-
-	if (!atomic_read(&nr_mmap_counters))
-		return;
-
-	mmap_event = (struct perf_mmap_event){
-		.vma	= vma,
-		/* .file_name */
-		/* .file_size */
-		.event  = {
-			.header = {
-				.type = PERF_EVENT_MMAP,
-				.misc = 0,
-				/* .size */
-			},
-			/* .pid */
-			/* .tid */
-			.start  = vma->vm_start,
-			.len    = vma->vm_end - vma->vm_start,
-			.pgoff  = vma->vm_pgoff,
-		},
-	};
-
-	perf_counter_mmap_event(&mmap_event);
-}
-
-/*
- * IRQ throttle logging
- */
-
-static void perf_log_throttle(struct perf_counter *counter, int enable)
-{
-	struct perf_output_handle handle;
-	int ret;
-
-	struct {
-		struct perf_event_header	header;
-		u64				time;
-		u64				id;
-		u64				stream_id;
-	} throttle_event = {
-		.header = {
-			.type = PERF_EVENT_THROTTLE,
-			.misc = 0,
-			.size = sizeof(throttle_event),
-		},
-		.time		= sched_clock(),
-		.id		= primary_counter_id(counter),
-		.stream_id	= counter->id,
-	};
-
-	if (enable)
-		throttle_event.header.type = PERF_EVENT_UNTHROTTLE;
-
-	ret = perf_output_begin(&handle, counter, sizeof(throttle_event), 1, 0);
-	if (ret)
-		return;
-
-	perf_output_put(&handle, throttle_event);
-	perf_output_end(&handle);
-}
-
-/*
- * Generic counter overflow handling, sampling.
- */
-
-int perf_counter_overflow(struct perf_counter *counter, int nmi,
-			  struct perf_sample_data *data)
-{
-	int events = atomic_read(&counter->event_limit);
-	int throttle = counter->pmu->unthrottle != NULL;
-	struct hw_perf_counter *hwc = &counter->hw;
-	int ret = 0;
-
-	if (!throttle) {
-		hwc->interrupts++;
-	} else {
-		if (hwc->interrupts != MAX_INTERRUPTS) {
-			hwc->interrupts++;
-			if (HZ * hwc->interrupts >
-					(u64)sysctl_perf_counter_sample_rate) {
-				hwc->interrupts = MAX_INTERRUPTS;
-				perf_log_throttle(counter, 0);
-				ret = 1;
-			}
-		} else {
-			/*
-			 * Keep re-disabling counters even though on the previous
-			 * pass we disabled it - just in case we raced with a
-			 * sched-in and the counter got enabled again:
-			 */
-			ret = 1;
-		}
-	}
-
-	if (counter->attr.freq) {
-		u64 now = sched_clock();
-		s64 delta = now - hwc->freq_stamp;
-
-		hwc->freq_stamp = now;
-
-		if (delta > 0 && delta < TICK_NSEC)
-			perf_adjust_period(counter, NSEC_PER_SEC / (int)delta);
-	}
-
-	/*
-	 * XXX event_limit might not quite work as expected on inherited
-	 * counters
-	 */
-
-	counter->pending_kill = POLL_IN;
-	if (events && atomic_dec_and_test(&counter->event_limit)) {
-		ret = 1;
-		counter->pending_kill = POLL_HUP;
-		if (nmi) {
-			counter->pending_disable = 1;
-			perf_pending_queue(&counter->pending,
-					   perf_pending_counter);
-		} else
-			perf_counter_disable(counter);
-	}
-
-	perf_counter_output(counter, nmi, data);
-	return ret;
-}
-
-/*
- * Generic software counter infrastructure
- */
-
-/*
- * We directly increment counter->count and keep a second value in
- * counter->hw.period_left to count intervals. This period counter
- * is kept in the range [-sample_period, 0] so that we can use the
- * sign as trigger.
- */
-
-static u64 perf_swcounter_set_period(struct perf_counter *counter)
-{
-	struct hw_perf_counter *hwc = &counter->hw;
-	u64 period = hwc->last_period;
-	u64 nr, offset;
-	s64 old, val;
-
-	hwc->last_period = hwc->sample_period;
-
-again:
-	old = val = atomic64_read(&hwc->period_left);
-	if (val < 0)
-		return 0;
-
-	nr = div64_u64(period + val, period);
-	offset = nr * period;
-	val -= offset;
-	if (atomic64_cmpxchg(&hwc->period_left, old, val) != old)
-		goto again;
-
-	return nr;
-}
-
-static void perf_swcounter_overflow(struct perf_counter *counter,
-				    int nmi, struct perf_sample_data *data)
-{
-	struct hw_perf_counter *hwc = &counter->hw;
-	u64 overflow;
-
-	data->period = counter->hw.last_period;
-	overflow = perf_swcounter_set_period(counter);
-
-	if (hwc->interrupts == MAX_INTERRUPTS)
-		return;
-
-	for (; overflow; overflow--) {
-		if (perf_counter_overflow(counter, nmi, data)) {
-			/*
-			 * We inhibit the overflow from happening when
-			 * hwc->interrupts == MAX_INTERRUPTS.
-			 */
-			break;
-		}
-	}
-}
-
-static void perf_swcounter_unthrottle(struct perf_counter *counter)
-{
-	/*
-	 * Nothing to do, we already reset hwc->interrupts.
-	 */
-}
-
-static void perf_swcounter_add(struct perf_counter *counter, u64 nr,
-			       int nmi, struct perf_sample_data *data)
-{
-	struct hw_perf_counter *hwc = &counter->hw;
-
-	atomic64_add(nr, &counter->count);
-
-	if (!hwc->sample_period)
-		return;
-
-	if (!data->regs)
-		return;
-
-	if (!atomic64_add_negative(nr, &hwc->period_left))
-		perf_swcounter_overflow(counter, nmi, data);
-}
-
-static int perf_swcounter_is_counting(struct perf_counter *counter)
-{
-	/*
-	 * The counter is active, we're good!
-	 */
-	if (counter->state == PERF_COUNTER_STATE_ACTIVE)
-		return 1;
-
-	/*
-	 * The counter is off/error, not counting.
-	 */
-	if (counter->state != PERF_COUNTER_STATE_INACTIVE)
-		return 0;
-
-	/*
-	 * The counter is inactive, if the context is active
-	 * we're part of a group that didn't make it on the 'pmu',
-	 * not counting.
-	 */
-	if (counter->ctx->is_active)
-		return 0;
-
-	/*
-	 * We're inactive and the context is too, this means the
-	 * task is scheduled out, we're counting events that happen
-	 * to us, like migration events.
-	 */
-	return 1;
-}
-
-static int perf_swcounter_match(struct perf_counter *counter,
-				enum perf_type_id type,
-				u32 event, struct pt_regs *regs)
-{
-	if (!perf_swcounter_is_counting(counter))
-		return 0;
-
-	if (counter->attr.type != type)
-		return 0;
-	if (counter->attr.config != event)
-		return 0;
-
-	if (regs) {
-		if (counter->attr.exclude_user && user_mode(regs))
-			return 0;
-
-		if (counter->attr.exclude_kernel && !user_mode(regs))
-			return 0;
-	}
-
-	return 1;
-}
-
-static void perf_swcounter_ctx_event(struct perf_counter_context *ctx,
-				     enum perf_type_id type,
-				     u32 event, u64 nr, int nmi,
-				     struct perf_sample_data *data)
-{
-	struct perf_counter *counter;
-
-	if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list))
-		return;
-
-	rcu_read_lock();
-	list_for_each_entry_rcu(counter, &ctx->event_list, event_entry) {
-		if (perf_swcounter_match(counter, type, event, data->regs))
-			perf_swcounter_add(counter, nr, nmi, data);
-	}
-	rcu_read_unlock();
-}
-
-static int *perf_swcounter_recursion_context(struct perf_cpu_context *cpuctx)
-{
-	if (in_nmi())
-		return &cpuctx->recursion[3];
-
-	if (in_irq())
-		return &cpuctx->recursion[2];
-
-	if (in_softirq())
-		return &cpuctx->recursion[1];
-
-	return &cpuctx->recursion[0];
-}
-
-static void do_perf_swcounter_event(enum perf_type_id type, u32 event,
-				    u64 nr, int nmi,
-				    struct perf_sample_data *data)
-{
-	struct perf_cpu_context *cpuctx = &get_cpu_var(perf_cpu_context);
-	int *recursion = perf_swcounter_recursion_context(cpuctx);
-	struct perf_counter_context *ctx;
-
-	if (*recursion)
-		goto out;
-
-	(*recursion)++;
-	barrier();
-
-	perf_swcounter_ctx_event(&cpuctx->ctx, type, event,
-				 nr, nmi, data);
-	rcu_read_lock();
-	/*
-	 * doesn't really matter which of the child contexts the
-	 * events ends up in.
-	 */
-	ctx = rcu_dereference(current->perf_counter_ctxp);
-	if (ctx)
-		perf_swcounter_ctx_event(ctx, type, event, nr, nmi, data);
-	rcu_read_unlock();
-
-	barrier();
-	(*recursion)--;
-
-out:
-	put_cpu_var(perf_cpu_context);
-}
-
-void __perf_swcounter_event(u32 event, u64 nr, int nmi,
-			    struct pt_regs *regs, u64 addr)
-{
-	struct perf_sample_data data = {
-		.regs = regs,
-		.addr = addr,
-	};
-
-	do_perf_swcounter_event(PERF_TYPE_SOFTWARE, event, nr, nmi, &data);
-}
-
-static void perf_swcounter_read(struct perf_counter *counter)
-{
-}
-
-static int perf_swcounter_enable(struct perf_counter *counter)
-{
-	struct hw_perf_counter *hwc = &counter->hw;
-
-	if (hwc->sample_period) {
-		hwc->last_period = hwc->sample_period;
-		perf_swcounter_set_period(counter);
-	}
-	return 0;
-}
-
-static void perf_swcounter_disable(struct perf_counter *counter)
-{
-}
-
-static const struct pmu perf_ops_generic = {
-	.enable		= perf_swcounter_enable,
-	.disable	= perf_swcounter_disable,
-	.read		= perf_swcounter_read,
-	.unthrottle	= perf_swcounter_unthrottle,
-};
-
-/*
- * hrtimer based swcounter callback
- */
-
-static enum hrtimer_restart perf_swcounter_hrtimer(struct hrtimer *hrtimer)
-{
-	enum hrtimer_restart ret = HRTIMER_RESTART;
-	struct perf_sample_data data;
-	struct perf_counter *counter;
-	u64 period;
-
-	counter	= container_of(hrtimer, struct perf_counter, hw.hrtimer);
-	counter->pmu->read(counter);
-
-	data.addr = 0;
-	data.regs = get_irq_regs();
-	/*
-	 * In case we exclude kernel IPs or are somehow not in interrupt
-	 * context, provide the next best thing, the user IP.
-	 */
-	if ((counter->attr.exclude_kernel || !data.regs) &&
-			!counter->attr.exclude_user)
-		data.regs = task_pt_regs(current);
-
-	if (data.regs) {
-		if (perf_counter_overflow(counter, 0, &data))
-			ret = HRTIMER_NORESTART;
-	}
-
-	period = max_t(u64, 10000, counter->hw.sample_period);
-	hrtimer_forward_now(hrtimer, ns_to_ktime(period));
-
-	return ret;
-}
-
-/*
- * Software counter: cpu wall time clock
- */
-
-static void cpu_clock_perf_counter_update(struct perf_counter *counter)
-{
-	int cpu = raw_smp_processor_id();
-	s64 prev;
-	u64 now;
-
-	now = cpu_clock(cpu);
-	prev = atomic64_read(&counter->hw.prev_count);
-	atomic64_set(&counter->hw.prev_count, now);
-	atomic64_add(now - prev, &counter->count);
-}
-
-static int cpu_clock_perf_counter_enable(struct perf_counter *counter)
-{
-	struct hw_perf_counter *hwc = &counter->hw;
-	int cpu = raw_smp_processor_id();
-
-	atomic64_set(&hwc->prev_count, cpu_clock(cpu));
-	hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
-	hwc->hrtimer.function = perf_swcounter_hrtimer;
-	if (hwc->sample_period) {
-		u64 period = max_t(u64, 10000, hwc->sample_period);
-		__hrtimer_start_range_ns(&hwc->hrtimer,
-				ns_to_ktime(period), 0,
-				HRTIMER_MODE_REL, 0);
-	}
-
-	return 0;
-}
-
-static void cpu_clock_perf_counter_disable(struct perf_counter *counter)
-{
-	if (counter->hw.sample_period)
-		hrtimer_cancel(&counter->hw.hrtimer);
-	cpu_clock_perf_counter_update(counter);
-}
-
-static void cpu_clock_perf_counter_read(struct perf_counter *counter)
-{
-	cpu_clock_perf_counter_update(counter);
-}
-
-static const struct pmu perf_ops_cpu_clock = {
-	.enable		= cpu_clock_perf_counter_enable,
-	.disable	= cpu_clock_perf_counter_disable,
-	.read		= cpu_clock_perf_counter_read,
-};
-
-/*
- * Software counter: task time clock
- */
-
-static void task_clock_perf_counter_update(struct perf_counter *counter, u64 now)
-{
-	u64 prev;
-	s64 delta;
-
-	prev = atomic64_xchg(&counter->hw.prev_count, now);
-	delta = now - prev;
-	atomic64_add(delta, &counter->count);
-}
-
-static int task_clock_perf_counter_enable(struct perf_counter *counter)
-{
-	struct hw_perf_counter *hwc = &counter->hw;
-	u64 now;
-
-	now = counter->ctx->time;
-
-	atomic64_set(&hwc->prev_count, now);
-	hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
-	hwc->hrtimer.function = perf_swcounter_hrtimer;
-	if (hwc->sample_period) {
-		u64 period = max_t(u64, 10000, hwc->sample_period);
-		__hrtimer_start_range_ns(&hwc->hrtimer,
-				ns_to_ktime(period), 0,
-				HRTIMER_MODE_REL, 0);
-	}
-
-	return 0;
-}
-
-static void task_clock_perf_counter_disable(struct perf_counter *counter)
-{
-	if (counter->hw.sample_period)
-		hrtimer_cancel(&counter->hw.hrtimer);
-	task_clock_perf_counter_update(counter, counter->ctx->time);
-
-}
-
-static void task_clock_perf_counter_read(struct perf_counter *counter)
-{
-	u64 time;
-
-	if (!in_nmi()) {
-		update_context_time(counter->ctx);
-		time = counter->ctx->time;
-	} else {
-		u64 now = perf_clock();
-		u64 delta = now - counter->ctx->timestamp;
-		time = counter->ctx->time + delta;
-	}
-
-	task_clock_perf_counter_update(counter, time);
-}
-
-static const struct pmu perf_ops_task_clock = {
-	.enable		= task_clock_perf_counter_enable,
-	.disable	= task_clock_perf_counter_disable,
-	.read		= task_clock_perf_counter_read,
-};
-
-#ifdef CONFIG_EVENT_PROFILE
-void perf_tpcounter_event(int event_id, u64 addr, u64 count, void *record,
-			  int entry_size)
-{
-	struct perf_raw_record raw = {
-		.size = entry_size,
-		.data = record,
-	};
-
-	struct perf_sample_data data = {
-		.regs = get_irq_regs(),
-		.addr = addr,
-		.raw = &raw,
-	};
-
-	if (!data.regs)
-		data.regs = task_pt_regs(current);
-
-	do_perf_swcounter_event(PERF_TYPE_TRACEPOINT, event_id, count, 1, &data);
-}
-EXPORT_SYMBOL_GPL(perf_tpcounter_event);
-
-extern int ftrace_profile_enable(int);
-extern void ftrace_profile_disable(int);
-
-static void tp_perf_counter_destroy(struct perf_counter *counter)
-{
-	ftrace_profile_disable(counter->attr.config);
-}
-
-static const struct pmu *tp_perf_counter_init(struct perf_counter *counter)
-{
-	/*
-	 * Raw tracepoint data is a severe data leak, only allow root to
-	 * have these.
-	 */
-	if ((counter->attr.sample_type & PERF_SAMPLE_RAW) &&
-			perf_paranoid_tracepoint_raw() &&
-			!capable(CAP_SYS_ADMIN))
-		return ERR_PTR(-EPERM);
-
-	if (ftrace_profile_enable(counter->attr.config))
-		return NULL;
-
-	counter->destroy = tp_perf_counter_destroy;
-
-	return &perf_ops_generic;
-}
-#else
-static const struct pmu *tp_perf_counter_init(struct perf_counter *counter)
-{
-	return NULL;
-}
-#endif
-
-atomic_t perf_swcounter_enabled[PERF_COUNT_SW_MAX];
-
-static void sw_perf_counter_destroy(struct perf_counter *counter)
-{
-	u64 event = counter->attr.config;
-
-	WARN_ON(counter->parent);
-
-	atomic_dec(&perf_swcounter_enabled[event]);
-}
-
-static const struct pmu *sw_perf_counter_init(struct perf_counter *counter)
-{
-	const struct pmu *pmu = NULL;
-	u64 event = counter->attr.config;
-
-	/*
-	 * Software counters (currently) can't in general distinguish
-	 * between user, kernel and hypervisor events.
-	 * However, context switches and cpu migrations are considered
-	 * to be kernel events, and page faults are never hypervisor
-	 * events.
-	 */
-	switch (event) {
-	case PERF_COUNT_SW_CPU_CLOCK:
-		pmu = &perf_ops_cpu_clock;
-
-		break;
-	case PERF_COUNT_SW_TASK_CLOCK:
-		/*
-		 * If the user instantiates this as a per-cpu counter,
-		 * use the cpu_clock counter instead.
-		 */
-		if (counter->ctx->task)
-			pmu = &perf_ops_task_clock;
-		else
-			pmu = &perf_ops_cpu_clock;
-
-		break;
-	case PERF_COUNT_SW_PAGE_FAULTS:
-	case PERF_COUNT_SW_PAGE_FAULTS_MIN:
-	case PERF_COUNT_SW_PAGE_FAULTS_MAJ:
-	case PERF_COUNT_SW_CONTEXT_SWITCHES:
-	case PERF_COUNT_SW_CPU_MIGRATIONS:
-		if (!counter->parent) {
-			atomic_inc(&perf_swcounter_enabled[event]);
-			counter->destroy = sw_perf_counter_destroy;
-		}
-		pmu = &perf_ops_generic;
-		break;
-	}
-
-	return pmu;
-}
-
-/*
- * Allocate and initialize a counter structure
- */
-static struct perf_counter *
-perf_counter_alloc(struct perf_counter_attr *attr,
-		   int cpu,
-		   struct perf_counter_context *ctx,
-		   struct perf_counter *group_leader,
-		   struct perf_counter *parent_counter,
-		   gfp_t gfpflags)
-{
-	const struct pmu *pmu;
-	struct perf_counter *counter;
-	struct hw_perf_counter *hwc;
-	long err;
-
-	counter = kzalloc(sizeof(*counter), gfpflags);
-	if (!counter)
-		return ERR_PTR(-ENOMEM);
-
-	/*
-	 * Single counters are their own group leaders, with an
-	 * empty sibling list:
-	 */
-	if (!group_leader)
-		group_leader = counter;
-
-	mutex_init(&counter->child_mutex);
-	INIT_LIST_HEAD(&counter->child_list);
-
-	INIT_LIST_HEAD(&counter->list_entry);
-	INIT_LIST_HEAD(&counter->event_entry);
-	INIT_LIST_HEAD(&counter->sibling_list);
-	init_waitqueue_head(&counter->waitq);
-
-	mutex_init(&counter->mmap_mutex);
-
-	counter->cpu		= cpu;
-	counter->attr		= *attr;
-	counter->group_leader	= group_leader;
-	counter->pmu		= NULL;
-	counter->ctx		= ctx;
-	counter->oncpu		= -1;
-
-	counter->parent		= parent_counter;
-
-	counter->ns		= get_pid_ns(current->nsproxy->pid_ns);
-	counter->id		= atomic64_inc_return(&perf_counter_id);
-
-	counter->state		= PERF_COUNTER_STATE_INACTIVE;
-
-	if (attr->disabled)
-		counter->state = PERF_COUNTER_STATE_OFF;
-
-	pmu = NULL;
-
-	hwc = &counter->hw;
-	hwc->sample_period = attr->sample_period;
-	if (attr->freq && attr->sample_freq)
-		hwc->sample_period = 1;
-	hwc->last_period = hwc->sample_period;
-
-	atomic64_set(&hwc->period_left, hwc->sample_period);
-
-	/*
-	 * we currently do not support PERF_FORMAT_GROUP on inherited counters
-	 */
-	if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP))
-		goto done;
-
-	switch (attr->type) {
-	case PERF_TYPE_RAW:
-	case PERF_TYPE_HARDWARE:
-	case PERF_TYPE_HW_CACHE:
-		pmu = hw_perf_counter_init(counter);
-		break;
-
-	case PERF_TYPE_SOFTWARE:
-		pmu = sw_perf_counter_init(counter);
-		break;
-
-	case PERF_TYPE_TRACEPOINT:
-		pmu = tp_perf_counter_init(counter);
-		break;
-
-	default:
-		break;
-	}
-done:
-	err = 0;
-	if (!pmu)
-		err = -EINVAL;
-	else if (IS_ERR(pmu))
-		err = PTR_ERR(pmu);
-
-	if (err) {
-		if (counter->ns)
-			put_pid_ns(counter->ns);
-		kfree(counter);
-		return ERR_PTR(err);
-	}
-
-	counter->pmu = pmu;
-
-	if (!counter->parent) {
-		atomic_inc(&nr_counters);
-		if (counter->attr.mmap)
-			atomic_inc(&nr_mmap_counters);
-		if (counter->attr.comm)
-			atomic_inc(&nr_comm_counters);
-		if (counter->attr.task)
-			atomic_inc(&nr_task_counters);
-	}
-
-	return counter;
-}
-
-static int perf_copy_attr(struct perf_counter_attr __user *uattr,
-			  struct perf_counter_attr *attr)
-{
-	int ret;
-	u32 size;
-
-	if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0))
-		return -EFAULT;
-
-	/*
-	 * zero the full structure, so that a short copy will be nice.
-	 */
-	memset(attr, 0, sizeof(*attr));
-
-	ret = get_user(size, &uattr->size);
-	if (ret)
-		return ret;
-
-	if (size > PAGE_SIZE)	/* silly large */
-		goto err_size;
-
-	if (!size)		/* abi compat */
-		size = PERF_ATTR_SIZE_VER0;
-
-	if (size < PERF_ATTR_SIZE_VER0)
-		goto err_size;
-
-	/*
-	 * If we're handed a bigger struct than we know of,
-	 * ensure all the unknown bits are 0.
-	 */
-	if (size > sizeof(*attr)) {
-		unsigned long val;
-		unsigned long __user *addr;
-		unsigned long __user *end;
-
-		addr = PTR_ALIGN((void __user *)uattr + sizeof(*attr),
-				sizeof(unsigned long));
-		end  = PTR_ALIGN((void __user *)uattr + size,
-				sizeof(unsigned long));
-
-		for (; addr < end; addr += sizeof(unsigned long)) {
-			ret = get_user(val, addr);
-			if (ret)
-				return ret;
-			if (val)
-				goto err_size;
-		}
-		size = sizeof(*attr);
-	}
-
-	ret = copy_from_user(attr, uattr, size);
-	if (ret)
-		return -EFAULT;
-
-	/*
-	 * If the type exists, the corresponding creation will verify
-	 * the attr->config.
-	 */
-	if (attr->type >= PERF_TYPE_MAX)
-		return -EINVAL;
-
-	if (attr->__reserved_1 || attr->__reserved_2 || attr->__reserved_3)
-		return -EINVAL;
-
-	if (attr->sample_type & ~(PERF_SAMPLE_MAX-1))
-		return -EINVAL;
-
-	if (attr->read_format & ~(PERF_FORMAT_MAX-1))
-		return -EINVAL;
-
-out:
-	return ret;
-
-err_size:
-	put_user(sizeof(*attr), &uattr->size);
-	ret = -E2BIG;
-	goto out;
-}
-
-int perf_counter_set_output(struct perf_counter *counter, int output_fd)
-{
-	struct perf_counter *output_counter = NULL;
-	struct file *output_file = NULL;
-	struct perf_counter *old_output;
-	int fput_needed = 0;
-	int ret = -EINVAL;
-
-	if (!output_fd)
-		goto set;
-
-	output_file = fget_light(output_fd, &fput_needed);
-	if (!output_file)
-		return -EBADF;
-
-	if (output_file->f_op != &perf_fops)
-		goto out;
-
-	output_counter = output_file->private_data;
-
-	/* Don't chain output fds */
-	if (output_counter->output)
-		goto out;
-
-	/* Don't set an output fd when we already have an output channel */
-	if (counter->data)
-		goto out;
-
-	atomic_long_inc(&output_file->f_count);
-
-set:
-	mutex_lock(&counter->mmap_mutex);
-	old_output = counter->output;
-	rcu_assign_pointer(counter->output, output_counter);
-	mutex_unlock(&counter->mmap_mutex);
-
-	if (old_output) {
-		/*
-		 * we need to make sure no existing perf_output_*()
-		 * is still referencing this counter.
-		 */
-		synchronize_rcu();
-		fput(old_output->filp);
-	}
-
-	ret = 0;
-out:
-	fput_light(output_file, fput_needed);
-	return ret;
-}
-
-/**
- * sys_perf_counter_open - open a performance counter, associate it to a task/cpu
- *
- * @attr_uptr:	event type attributes for monitoring/sampling
- * @pid:		target pid
- * @cpu:		target cpu
- * @group_fd:		group leader counter fd
- */
-SYSCALL_DEFINE5(perf_counter_open,
-		struct perf_counter_attr __user *, attr_uptr,
-		pid_t, pid, int, cpu, int, group_fd, unsigned long, flags)
-{
-	struct perf_counter *counter, *group_leader;
-	struct perf_counter_attr attr;
-	struct perf_counter_context *ctx;
-	struct file *counter_file = NULL;
-	struct file *group_file = NULL;
-	int fput_needed = 0;
-	int fput_needed2 = 0;
-	int err;
-
-	/* for future expandability... */
-	if (flags & ~(PERF_FLAG_FD_NO_GROUP | PERF_FLAG_FD_OUTPUT))
-		return -EINVAL;
-
-	err = perf_copy_attr(attr_uptr, &attr);
-	if (err)
-		return err;
-
-	if (!attr.exclude_kernel) {
-		if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN))
-			return -EACCES;
-	}
-
-	if (attr.freq) {
-		if (attr.sample_freq > sysctl_perf_counter_sample_rate)
-			return -EINVAL;
-	}
-
-	/*
-	 * Get the target context (task or percpu):
-	 */
-	ctx = find_get_context(pid, cpu);
-	if (IS_ERR(ctx))
-		return PTR_ERR(ctx);
-
-	/*
-	 * Look up the group leader (we will attach this counter to it):
-	 */
-	group_leader = NULL;
-	if (group_fd != -1 && !(flags & PERF_FLAG_FD_NO_GROUP)) {
-		err = -EINVAL;
-		group_file = fget_light(group_fd, &fput_needed);
-		if (!group_file)
-			goto err_put_context;
-		if (group_file->f_op != &perf_fops)
-			goto err_put_context;
-
-		group_leader = group_file->private_data;
-		/*
-		 * Do not allow a recursive hierarchy (this new sibling
-		 * becoming part of another group-sibling):
-		 */
-		if (group_leader->group_leader != group_leader)
-			goto err_put_context;
-		/*
-		 * Do not allow to attach to a group in a different
-		 * task or CPU context:
-		 */
-		if (group_leader->ctx != ctx)
-			goto err_put_context;
-		/*
-		 * Only a group leader can be exclusive or pinned
-		 */
-		if (attr.exclusive || attr.pinned)
-			goto err_put_context;
-	}
-
-	counter = perf_counter_alloc(&attr, cpu, ctx, group_leader,
-				     NULL, GFP_KERNEL);
-	err = PTR_ERR(counter);
-	if (IS_ERR(counter))
-		goto err_put_context;
-
-	err = anon_inode_getfd("[perf_counter]", &perf_fops, counter, 0);
-	if (err < 0)
-		goto err_free_put_context;
-
-	counter_file = fget_light(err, &fput_needed2);
-	if (!counter_file)
-		goto err_free_put_context;
-
-	if (flags & PERF_FLAG_FD_OUTPUT) {
-		err = perf_counter_set_output(counter, group_fd);
-		if (err)
-			goto err_fput_free_put_context;
-	}
-
-	counter->filp = counter_file;
-	WARN_ON_ONCE(ctx->parent_ctx);
-	mutex_lock(&ctx->mutex);
-	perf_install_in_context(ctx, counter, cpu);
-	++ctx->generation;
-	mutex_unlock(&ctx->mutex);
-
-	counter->owner = current;
-	get_task_struct(current);
-	mutex_lock(&current->perf_counter_mutex);
-	list_add_tail(&counter->owner_entry, &current->perf_counter_list);
-	mutex_unlock(&current->perf_counter_mutex);
-
-err_fput_free_put_context:
-	fput_light(counter_file, fput_needed2);
-
-err_free_put_context:
-	if (err < 0)
-		kfree(counter);
-
-err_put_context:
-	if (err < 0)
-		put_ctx(ctx);
-
-	fput_light(group_file, fput_needed);
-
-	return err;
-}
-
-/*
- * inherit a counter from parent task to child task:
- */
-static struct perf_counter *
-inherit_counter(struct perf_counter *parent_counter,
-	      struct task_struct *parent,
-	      struct perf_counter_context *parent_ctx,
-	      struct task_struct *child,
-	      struct perf_counter *group_leader,
-	      struct perf_counter_context *child_ctx)
-{
-	struct perf_counter *child_counter;
-
-	/*
-	 * Instead of creating recursive hierarchies of counters,
-	 * we link inherited counters back to the original parent,
-	 * which has a filp for sure, which we use as the reference
-	 * count:
-	 */
-	if (parent_counter->parent)
-		parent_counter = parent_counter->parent;
-
-	child_counter = perf_counter_alloc(&parent_counter->attr,
-					   parent_counter->cpu, child_ctx,
-					   group_leader, parent_counter,
-					   GFP_KERNEL);
-	if (IS_ERR(child_counter))
-		return child_counter;
-	get_ctx(child_ctx);
-
-	/*
-	 * Make the child state follow the state of the parent counter,
-	 * not its attr.disabled bit.  We hold the parent's mutex,
-	 * so we won't race with perf_counter_{en, dis}able_family.
-	 */
-	if (parent_counter->state >= PERF_COUNTER_STATE_INACTIVE)
-		child_counter->state = PERF_COUNTER_STATE_INACTIVE;
-	else
-		child_counter->state = PERF_COUNTER_STATE_OFF;
-
-	if (parent_counter->attr.freq)
-		child_counter->hw.sample_period = parent_counter->hw.sample_period;
-
-	/*
-	 * Link it up in the child's context:
-	 */
-	add_counter_to_ctx(child_counter, child_ctx);
-
-	/*
-	 * Get a reference to the parent filp - we will fput it
-	 * when the child counter exits. This is safe to do because
-	 * we are in the parent and we know that the filp still
-	 * exists and has a nonzero count:
-	 */
-	atomic_long_inc(&parent_counter->filp->f_count);
-
-	/*
-	 * Link this into the parent counter's child list
-	 */
-	WARN_ON_ONCE(parent_counter->ctx->parent_ctx);
-	mutex_lock(&parent_counter->child_mutex);
-	list_add_tail(&child_counter->child_list, &parent_counter->child_list);
-	mutex_unlock(&parent_counter->child_mutex);
-
-	return child_counter;
-}
-
-static int inherit_group(struct perf_counter *parent_counter,
-	      struct task_struct *parent,
-	      struct perf_counter_context *parent_ctx,
-	      struct task_struct *child,
-	      struct perf_counter_context *child_ctx)
-{
-	struct perf_counter *leader;
-	struct perf_counter *sub;
-	struct perf_counter *child_ctr;
-
-	leader = inherit_counter(parent_counter, parent, parent_ctx,
-				 child, NULL, child_ctx);
-	if (IS_ERR(leader))
-		return PTR_ERR(leader);
-	list_for_each_entry(sub, &parent_counter->sibling_list, list_entry) {
-		child_ctr = inherit_counter(sub, parent, parent_ctx,
-					    child, leader, child_ctx);
-		if (IS_ERR(child_ctr))
-			return PTR_ERR(child_ctr);
-	}
-	return 0;
-}
-
-static void sync_child_counter(struct perf_counter *child_counter,
-			       struct task_struct *child)
-{
-	struct perf_counter *parent_counter = child_counter->parent;
-	u64 child_val;
-
-	if (child_counter->attr.inherit_stat)
-		perf_counter_read_event(child_counter, child);
-
-	child_val = atomic64_read(&child_counter->count);
-
-	/*
-	 * Add back the child's count to the parent's count:
-	 */
-	atomic64_add(child_val, &parent_counter->count);
-	atomic64_add(child_counter->total_time_enabled,
-		     &parent_counter->child_total_time_enabled);
-	atomic64_add(child_counter->total_time_running,
-		     &parent_counter->child_total_time_running);
-
-	/*
-	 * Remove this counter from the parent's list
-	 */
-	WARN_ON_ONCE(parent_counter->ctx->parent_ctx);
-	mutex_lock(&parent_counter->child_mutex);
-	list_del_init(&child_counter->child_list);
-	mutex_unlock(&parent_counter->child_mutex);
-
-	/*
-	 * Release the parent counter, if this was the last
-	 * reference to it.
-	 */
-	fput(parent_counter->filp);
-}
-
-static void
-__perf_counter_exit_task(struct perf_counter *child_counter,
-			 struct perf_counter_context *child_ctx,
-			 struct task_struct *child)
-{
-	struct perf_counter *parent_counter;
-
-	update_counter_times(child_counter);
-	perf_counter_remove_from_context(child_counter);
-
-	parent_counter = child_counter->parent;
-	/*
-	 * It can happen that parent exits first, and has counters
-	 * that are still around due to the child reference. These
-	 * counters need to be zapped - but otherwise linger.
-	 */
-	if (parent_counter) {
-		sync_child_counter(child_counter, child);
-		free_counter(child_counter);
-	}
-}
-
-/*
- * When a child task exits, feed back counter values to parent counters.
- */
-void perf_counter_exit_task(struct task_struct *child)
-{
-	struct perf_counter *child_counter, *tmp;
-	struct perf_counter_context *child_ctx;
-	unsigned long flags;
-
-	if (likely(!child->perf_counter_ctxp)) {
-		perf_counter_task(child, NULL, 0);
-		return;
-	}
-
-	local_irq_save(flags);
-	/*
-	 * We can't reschedule here because interrupts are disabled,
-	 * and either child is current or it is a task that can't be
-	 * scheduled, so we are now safe from rescheduling changing
-	 * our context.
-	 */
-	child_ctx = child->perf_counter_ctxp;
-	__perf_counter_task_sched_out(child_ctx);
-
-	/*
-	 * Take the context lock here so that if find_get_context is
-	 * reading child->perf_counter_ctxp, we wait until it has
-	 * incremented the context's refcount before we do put_ctx below.
-	 */
-	spin_lock(&child_ctx->lock);
-	child->perf_counter_ctxp = NULL;
-	/*
-	 * If this context is a clone; unclone it so it can't get
-	 * swapped to another process while we're removing all
-	 * the counters from it.
-	 */
-	unclone_ctx(child_ctx);
-	spin_unlock_irqrestore(&child_ctx->lock, flags);
-
-	/*
-	 * Report the task dead after unscheduling the counters so that we
-	 * won't get any samples after PERF_EVENT_EXIT. We can however still
-	 * get a few PERF_EVENT_READ events.
-	 */
-	perf_counter_task(child, child_ctx, 0);
-
-	/*
-	 * We can recurse on the same lock type through:
-	 *
-	 *   __perf_counter_exit_task()
-	 *     sync_child_counter()
-	 *       fput(parent_counter->filp)
-	 *         perf_release()
-	 *           mutex_lock(&ctx->mutex)
-	 *
-	 * But since its the parent context it won't be the same instance.
-	 */
-	mutex_lock_nested(&child_ctx->mutex, SINGLE_DEPTH_NESTING);
-
-again:
-	list_for_each_entry_safe(child_counter, tmp, &child_ctx->counter_list,
-				 list_entry)
-		__perf_counter_exit_task(child_counter, child_ctx, child);
-
-	/*
-	 * If the last counter was a group counter, it will have appended all
-	 * its siblings to the list, but we obtained 'tmp' before that which
-	 * will still point to the list head terminating the iteration.
-	 */
-	if (!list_empty(&child_ctx->counter_list))
-		goto again;
-
-	mutex_unlock(&child_ctx->mutex);
-
-	put_ctx(child_ctx);
-}
-
-/*
- * free an unexposed, unused context as created by inheritance by
- * init_task below, used by fork() in case of fail.
- */
-void perf_counter_free_task(struct task_struct *task)
-{
-	struct perf_counter_context *ctx = task->perf_counter_ctxp;
-	struct perf_counter *counter, *tmp;
-
-	if (!ctx)
-		return;
-
-	mutex_lock(&ctx->mutex);
-again:
-	list_for_each_entry_safe(counter, tmp, &ctx->counter_list, list_entry) {
-		struct perf_counter *parent = counter->parent;
-
-		if (WARN_ON_ONCE(!parent))
-			continue;
-
-		mutex_lock(&parent->child_mutex);
-		list_del_init(&counter->child_list);
-		mutex_unlock(&parent->child_mutex);
-
-		fput(parent->filp);
-
-		list_del_counter(counter, ctx);
-		free_counter(counter);
-	}
-
-	if (!list_empty(&ctx->counter_list))
-		goto again;
-
-	mutex_unlock(&ctx->mutex);
-
-	put_ctx(ctx);
-}
-
-/*
- * Initialize the perf_counter context in task_struct
- */
-int perf_counter_init_task(struct task_struct *child)
-{
-	struct perf_counter_context *child_ctx, *parent_ctx;
-	struct perf_counter_context *cloned_ctx;
-	struct perf_counter *counter;
-	struct task_struct *parent = current;
-	int inherited_all = 1;
-	int ret = 0;
-
-	child->perf_counter_ctxp = NULL;
-
-	mutex_init(&child->perf_counter_mutex);
-	INIT_LIST_HEAD(&child->perf_counter_list);
-
-	if (likely(!parent->perf_counter_ctxp))
-		return 0;
-
-	/*
-	 * This is executed from the parent task context, so inherit
-	 * counters that have been marked for cloning.
-	 * First allocate and initialize a context for the child.
-	 */
-
-	child_ctx = kmalloc(sizeof(struct perf_counter_context), GFP_KERNEL);
-	if (!child_ctx)
-		return -ENOMEM;
-
-	__perf_counter_init_context(child_ctx, child);
-	child->perf_counter_ctxp = child_ctx;
-	get_task_struct(child);
-
-	/*
-	 * If the parent's context is a clone, pin it so it won't get
-	 * swapped under us.
-	 */
-	parent_ctx = perf_pin_task_context(parent);
-
-	/*
-	 * No need to check if parent_ctx != NULL here; since we saw
-	 * it non-NULL earlier, the only reason for it to become NULL
-	 * is if we exit, and since we're currently in the middle of
-	 * a fork we can't be exiting at the same time.
-	 */
-
-	/*
-	 * Lock the parent list. No need to lock the child - not PID
-	 * hashed yet and not running, so nobody can access it.
-	 */
-	mutex_lock(&parent_ctx->mutex);
-
-	/*
-	 * We dont have to disable NMIs - we are only looking at
-	 * the list, not manipulating it:
-	 */
-	list_for_each_entry_rcu(counter, &parent_ctx->event_list, event_entry) {
-		if (counter != counter->group_leader)
-			continue;
-
-		if (!counter->attr.inherit) {
-			inherited_all = 0;
-			continue;
-		}
-
-		ret = inherit_group(counter, parent, parent_ctx,
-					     child, child_ctx);
-		if (ret) {
-			inherited_all = 0;
-			break;
-		}
-	}
-
-	if (inherited_all) {
-		/*
-		 * Mark the child context as a clone of the parent
-		 * context, or of whatever the parent is a clone of.
-		 * Note that if the parent is a clone, it could get
-		 * uncloned at any point, but that doesn't matter
-		 * because the list of counters and the generation
-		 * count can't have changed since we took the mutex.
-		 */
-		cloned_ctx = rcu_dereference(parent_ctx->parent_ctx);
-		if (cloned_ctx) {
-			child_ctx->parent_ctx = cloned_ctx;
-			child_ctx->parent_gen = parent_ctx->parent_gen;
-		} else {
-			child_ctx->parent_ctx = parent_ctx;
-			child_ctx->parent_gen = parent_ctx->generation;
-		}
-		get_ctx(child_ctx->parent_ctx);
-	}
-
-	mutex_unlock(&parent_ctx->mutex);
-
-	perf_unpin_context(parent_ctx);
-
-	return ret;
-}
-
-static void __cpuinit perf_counter_init_cpu(int cpu)
-{
-	struct perf_cpu_context *cpuctx;
-
-	cpuctx = &per_cpu(perf_cpu_context, cpu);
-	__perf_counter_init_context(&cpuctx->ctx, NULL);
-
-	spin_lock(&perf_resource_lock);
-	cpuctx->max_pertask = perf_max_counters - perf_reserved_percpu;
-	spin_unlock(&perf_resource_lock);
-
-	hw_perf_counter_setup(cpu);
-}
-
-#ifdef CONFIG_HOTPLUG_CPU
-static void __perf_counter_exit_cpu(void *info)
-{
-	struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
-	struct perf_counter_context *ctx = &cpuctx->ctx;
-	struct perf_counter *counter, *tmp;
-
-	list_for_each_entry_safe(counter, tmp, &ctx->counter_list, list_entry)
-		__perf_counter_remove_from_context(counter);
-}
-static void perf_counter_exit_cpu(int cpu)
-{
-	struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu);
-	struct perf_counter_context *ctx = &cpuctx->ctx;
-
-	mutex_lock(&ctx->mutex);
-	smp_call_function_single(cpu, __perf_counter_exit_cpu, NULL, 1);
-	mutex_unlock(&ctx->mutex);
-}
-#else
-static inline void perf_counter_exit_cpu(int cpu) { }
-#endif
-
-static int __cpuinit
-perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu)
-{
-	unsigned int cpu = (long)hcpu;
-
-	switch (action) {
-
-	case CPU_UP_PREPARE:
-	case CPU_UP_PREPARE_FROZEN:
-		perf_counter_init_cpu(cpu);
-		break;
-
-	case CPU_ONLINE:
-	case CPU_ONLINE_FROZEN:
-		hw_perf_counter_setup_online(cpu);
-		break;
-
-	case CPU_DOWN_PREPARE:
-	case CPU_DOWN_PREPARE_FROZEN:
-		perf_counter_exit_cpu(cpu);
-		break;
-
-	default:
-		break;
-	}
-
-	return NOTIFY_OK;
-}
-
-/*
- * This has to have a higher priority than migration_notifier in sched.c.
- */
-static struct notifier_block __cpuinitdata perf_cpu_nb = {
-	.notifier_call		= perf_cpu_notify,
-	.priority		= 20,
-};
-
-void __init perf_counter_init(void)
-{
-	perf_cpu_notify(&perf_cpu_nb, (unsigned long)CPU_UP_PREPARE,
-			(void *)(long)smp_processor_id());
-	perf_cpu_notify(&perf_cpu_nb, (unsigned long)CPU_ONLINE,
-			(void *)(long)smp_processor_id());
-	register_cpu_notifier(&perf_cpu_nb);
-}
-
-static ssize_t perf_show_reserve_percpu(struct sysdev_class *class, char *buf)
-{
-	return sprintf(buf, "%d\n", perf_reserved_percpu);
-}
-
-static ssize_t
-perf_set_reserve_percpu(struct sysdev_class *class,
-			const char *buf,
-			size_t count)
-{
-	struct perf_cpu_context *cpuctx;
-	unsigned long val;
-	int err, cpu, mpt;
-
-	err = strict_strtoul(buf, 10, &val);
-	if (err)
-		return err;
-	if (val > perf_max_counters)
-		return -EINVAL;
-
-	spin_lock(&perf_resource_lock);
-	perf_reserved_percpu = val;
-	for_each_online_cpu(cpu) {
-		cpuctx = &per_cpu(perf_cpu_context, cpu);
-		spin_lock_irq(&cpuctx->ctx.lock);
-		mpt = min(perf_max_counters - cpuctx->ctx.nr_counters,
-			  perf_max_counters - perf_reserved_percpu);
-		cpuctx->max_pertask = mpt;
-		spin_unlock_irq(&cpuctx->ctx.lock);
-	}
-	spin_unlock(&perf_resource_lock);
-
-	return count;
-}
-
-static ssize_t perf_show_overcommit(struct sysdev_class *class, char *buf)
-{
-	return sprintf(buf, "%d\n", perf_overcommit);
-}
-
-static ssize_t
-perf_set_overcommit(struct sysdev_class *class, const char *buf, size_t count)
-{
-	unsigned long val;
-	int err;
-
-	err = strict_strtoul(buf, 10, &val);
-	if (err)
-		return err;
-	if (val > 1)
-		return -EINVAL;
-
-	spin_lock(&perf_resource_lock);
-	perf_overcommit = val;
-	spin_unlock(&perf_resource_lock);
-
-	return count;
-}
-
-static SYSDEV_CLASS_ATTR(
-				reserve_percpu,
-				0644,
-				perf_show_reserve_percpu,
-				perf_set_reserve_percpu
-			);
-
-static SYSDEV_CLASS_ATTR(
-				overcommit,
-				0644,
-				perf_show_overcommit,
-				perf_set_overcommit
-			);
-
-static struct attribute *perfclass_attrs[] = {
-	&attr_reserve_percpu.attr,
-	&attr_overcommit.attr,
-	NULL
-};
-
-static struct attribute_group perfclass_attr_group = {
-	.attrs			= perfclass_attrs,
-	.name			= "perf_counters",
-};
-
-static int __init perf_counter_sysfs_init(void)
-{
-	return sysfs_create_group(&cpu_sysdev_class.kset.kobj,
-				  &perfclass_attr_group);
-}
-device_initcall(perf_counter_sysfs_init);
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
new file mode 100644
index 00000000000..9d0b5c66588
--- /dev/null
+++ b/kernel/perf_event.c
@@ -0,0 +1,5108 @@
+/*
+ * Performance events core code:
+ *
+ *  Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
+ *  Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar
+ *  Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
+ *  Copyright  ©  2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
+ *
+ * For licensing details see kernel-base/COPYING
+ */
+
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/cpu.h>
+#include <linux/smp.h>
+#include <linux/file.h>
+#include <linux/poll.h>
+#include <linux/sysfs.h>
+#include <linux/dcache.h>
+#include <linux/percpu.h>
+#include <linux/ptrace.h>
+#include <linux/vmstat.h>
+#include <linux/vmalloc.h>
+#include <linux/hardirq.h>
+#include <linux/rculist.h>
+#include <linux/uaccess.h>
+#include <linux/syscalls.h>
+#include <linux/anon_inodes.h>
+#include <linux/kernel_stat.h>
+#include <linux/perf_event.h>
+
+#include <asm/irq_regs.h>
+
+/*
+ * Each CPU has a list of per CPU events:
+ */
+DEFINE_PER_CPU(struct perf_cpu_context, perf_cpu_context);
+
+int perf_max_events __read_mostly = 1;
+static int perf_reserved_percpu __read_mostly;
+static int perf_overcommit __read_mostly = 1;
+
+static atomic_t nr_events __read_mostly;
+static atomic_t nr_mmap_events __read_mostly;
+static atomic_t nr_comm_events __read_mostly;
+static atomic_t nr_task_events __read_mostly;
+
+/*
+ * perf event paranoia level:
+ *  -1 - not paranoid at all
+ *   0 - disallow raw tracepoint access for unpriv
+ *   1 - disallow cpu events for unpriv
+ *   2 - disallow kernel profiling for unpriv
+ */
+int sysctl_perf_event_paranoid __read_mostly = 1;
+
+static inline bool perf_paranoid_tracepoint_raw(void)
+{
+	return sysctl_perf_event_paranoid > -1;
+}
+
+static inline bool perf_paranoid_cpu(void)
+{
+	return sysctl_perf_event_paranoid > 0;
+}
+
+static inline bool perf_paranoid_kernel(void)
+{
+	return sysctl_perf_event_paranoid > 1;
+}
+
+int sysctl_perf_event_mlock __read_mostly = 512; /* 'free' kb per user */
+
+/*
+ * max perf event sample rate
+ */
+int sysctl_perf_event_sample_rate __read_mostly = 100000;
+
+static atomic64_t perf_event_id;
+
+/*
+ * Lock for (sysadmin-configurable) event reservations:
+ */
+static DEFINE_SPINLOCK(perf_resource_lock);
+
+/*
+ * Architecture provided APIs - weak aliases:
+ */
+extern __weak const struct pmu *hw_perf_event_init(struct perf_event *event)
+{
+	return NULL;
+}
+
+void __weak hw_perf_disable(void)		{ barrier(); }
+void __weak hw_perf_enable(void)		{ barrier(); }
+
+void __weak hw_perf_event_setup(int cpu)	{ barrier(); }
+void __weak hw_perf_event_setup_online(int cpu)	{ barrier(); }
+
+int __weak
+hw_perf_group_sched_in(struct perf_event *group_leader,
+	       struct perf_cpu_context *cpuctx,
+	       struct perf_event_context *ctx, int cpu)
+{
+	return 0;
+}
+
+void __weak perf_event_print_debug(void)	{ }
+
+static DEFINE_PER_CPU(int, perf_disable_count);
+
+void __perf_disable(void)
+{
+	__get_cpu_var(perf_disable_count)++;
+}
+
+bool __perf_enable(void)
+{
+	return !--__get_cpu_var(perf_disable_count);
+}
+
+void perf_disable(void)
+{
+	__perf_disable();
+	hw_perf_disable();
+}
+
+void perf_enable(void)
+{
+	if (__perf_enable())
+		hw_perf_enable();
+}
+
+static void get_ctx(struct perf_event_context *ctx)
+{
+	WARN_ON(!atomic_inc_not_zero(&ctx->refcount));
+}
+
+static void free_ctx(struct rcu_head *head)
+{
+	struct perf_event_context *ctx;
+
+	ctx = container_of(head, struct perf_event_context, rcu_head);
+	kfree(ctx);
+}
+
+static void put_ctx(struct perf_event_context *ctx)
+{
+	if (atomic_dec_and_test(&ctx->refcount)) {
+		if (ctx->parent_ctx)
+			put_ctx(ctx->parent_ctx);
+		if (ctx->task)
+			put_task_struct(ctx->task);
+		call_rcu(&ctx->rcu_head, free_ctx);
+	}
+}
+
+static void unclone_ctx(struct perf_event_context *ctx)
+{
+	if (ctx->parent_ctx) {
+		put_ctx(ctx->parent_ctx);
+		ctx->parent_ctx = NULL;
+	}
+}
+
+/*
+ * If we inherit events we want to return the parent event id
+ * to userspace.
+ */
+static u64 primary_event_id(struct perf_event *event)
+{
+	u64 id = event->id;
+
+	if (event->parent)
+		id = event->parent->id;
+
+	return id;
+}
+
+/*
+ * Get the perf_event_context for a task and lock it.
+ * This has to cope with with the fact that until it is locked,
+ * the context could get moved to another task.
+ */
+static struct perf_event_context *
+perf_lock_task_context(struct task_struct *task, unsigned long *flags)
+{
+	struct perf_event_context *ctx;
+
+	rcu_read_lock();
+ retry:
+	ctx = rcu_dereference(task->perf_event_ctxp);
+	if (ctx) {
+		/*
+		 * If this context is a clone of another, it might
+		 * get swapped for another underneath us by
+		 * perf_event_task_sched_out, though the
+		 * rcu_read_lock() protects us from any context
+		 * getting freed.  Lock the context and check if it
+		 * got swapped before we could get the lock, and retry
+		 * if so.  If we locked the right context, then it
+		 * can't get swapped on us any more.
+		 */
+		spin_lock_irqsave(&ctx->lock, *flags);
+		if (ctx != rcu_dereference(task->perf_event_ctxp)) {
+			spin_unlock_irqrestore(&ctx->lock, *flags);
+			goto retry;
+		}
+
+		if (!atomic_inc_not_zero(&ctx->refcount)) {
+			spin_unlock_irqrestore(&ctx->lock, *flags);
+			ctx = NULL;
+		}
+	}
+	rcu_read_unlock();
+	return ctx;
+}
+
+/*
+ * Get the context for a task and increment its pin_count so it
+ * can't get swapped to another task.  This also increments its
+ * reference count so that the context can't get freed.
+ */
+static struct perf_event_context *perf_pin_task_context(struct task_struct *task)
+{
+	struct perf_event_context *ctx;
+	unsigned long flags;
+
+	ctx = perf_lock_task_context(task, &flags);
+	if (ctx) {
+		++ctx->pin_count;
+		spin_unlock_irqrestore(&ctx->lock, flags);
+	}
+	return ctx;
+}
+
+static void perf_unpin_context(struct perf_event_context *ctx)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&ctx->lock, flags);
+	--ctx->pin_count;
+	spin_unlock_irqrestore(&ctx->lock, flags);
+	put_ctx(ctx);
+}
+
+/*
+ * Add a event from the lists for its context.
+ * Must be called with ctx->mutex and ctx->lock held.
+ */
+static void
+list_add_event(struct perf_event *event, struct perf_event_context *ctx)
+{
+	struct perf_event *group_leader = event->group_leader;
+
+	/*
+	 * Depending on whether it is a standalone or sibling event,
+	 * add it straight to the context's event list, or to the group
+	 * leader's sibling list:
+	 */
+	if (group_leader == event)
+		list_add_tail(&event->group_entry, &ctx->group_list);
+	else {
+		list_add_tail(&event->group_entry, &group_leader->sibling_list);
+		group_leader->nr_siblings++;
+	}
+
+	list_add_rcu(&event->event_entry, &ctx->event_list);
+	ctx->nr_events++;
+	if (event->attr.inherit_stat)
+		ctx->nr_stat++;
+}
+
+/*
+ * Remove a event from the lists for its context.
+ * Must be called with ctx->mutex and ctx->lock held.
+ */
+static void
+list_del_event(struct perf_event *event, struct perf_event_context *ctx)
+{
+	struct perf_event *sibling, *tmp;
+
+	if (list_empty(&event->group_entry))
+		return;
+	ctx->nr_events--;
+	if (event->attr.inherit_stat)
+		ctx->nr_stat--;
+
+	list_del_init(&event->group_entry);
+	list_del_rcu(&event->event_entry);
+
+	if (event->group_leader != event)
+		event->group_leader->nr_siblings--;
+
+	/*
+	 * If this was a group event with sibling events then
+	 * upgrade the siblings to singleton events by adding them
+	 * to the context list directly:
+	 */
+	list_for_each_entry_safe(sibling, tmp, &event->sibling_list, group_entry) {
+
+		list_move_tail(&sibling->group_entry, &ctx->group_list);
+		sibling->group_leader = sibling;
+	}
+}
+
+static void
+event_sched_out(struct perf_event *event,
+		  struct perf_cpu_context *cpuctx,
+		  struct perf_event_context *ctx)
+{
+	if (event->state != PERF_EVENT_STATE_ACTIVE)
+		return;
+
+	event->state = PERF_EVENT_STATE_INACTIVE;
+	if (event->pending_disable) {
+		event->pending_disable = 0;
+		event->state = PERF_EVENT_STATE_OFF;
+	}
+	event->tstamp_stopped = ctx->time;
+	event->pmu->disable(event);
+	event->oncpu = -1;
+
+	if (!is_software_event(event))
+		cpuctx->active_oncpu--;
+	ctx->nr_active--;
+	if (event->attr.exclusive || !cpuctx->active_oncpu)
+		cpuctx->exclusive = 0;
+}
+
+static void
+group_sched_out(struct perf_event *group_event,
+		struct perf_cpu_context *cpuctx,
+		struct perf_event_context *ctx)
+{
+	struct perf_event *event;
+
+	if (group_event->state != PERF_EVENT_STATE_ACTIVE)
+		return;
+
+	event_sched_out(group_event, cpuctx, ctx);
+
+	/*
+	 * Schedule out siblings (if any):
+	 */
+	list_for_each_entry(event, &group_event->sibling_list, group_entry)
+		event_sched_out(event, cpuctx, ctx);
+
+	if (group_event->attr.exclusive)
+		cpuctx->exclusive = 0;
+}
+
+/*
+ * Cross CPU call to remove a performance event
+ *
+ * We disable the event on the hardware level first. After that we
+ * remove it from the context list.
+ */
+static void __perf_event_remove_from_context(void *info)
+{
+	struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
+	struct perf_event *event = info;
+	struct perf_event_context *ctx = event->ctx;
+
+	/*
+	 * If this is a task context, we need to check whether it is
+	 * the current task context of this cpu. If not it has been
+	 * scheduled out before the smp call arrived.
+	 */
+	if (ctx->task && cpuctx->task_ctx != ctx)
+		return;
+
+	spin_lock(&ctx->lock);
+	/*
+	 * Protect the list operation against NMI by disabling the
+	 * events on a global level.
+	 */
+	perf_disable();
+
+	event_sched_out(event, cpuctx, ctx);
+
+	list_del_event(event, ctx);
+
+	if (!ctx->task) {
+		/*
+		 * Allow more per task events with respect to the
+		 * reservation:
+		 */
+		cpuctx->max_pertask =
+			min(perf_max_events - ctx->nr_events,
+			    perf_max_events - perf_reserved_percpu);
+	}
+
+	perf_enable();
+	spin_unlock(&ctx->lock);
+}
+
+
+/*
+ * Remove the event from a task's (or a CPU's) list of events.
+ *
+ * Must be called with ctx->mutex held.
+ *
+ * CPU events are removed with a smp call. For task events we only
+ * call when the task is on a CPU.
+ *
+ * If event->ctx is a cloned context, callers must make sure that
+ * every task struct that event->ctx->task could possibly point to
+ * remains valid.  This is OK when called from perf_release since
+ * that only calls us on the top-level context, which can't be a clone.
+ * When called from perf_event_exit_task, it's OK because the
+ * context has been detached from its task.
+ */
+static void perf_event_remove_from_context(struct perf_event *event)
+{
+	struct perf_event_context *ctx = event->ctx;
+	struct task_struct *task = ctx->task;
+
+	if (!task) {
+		/*
+		 * Per cpu events are removed via an smp call and
+		 * the removal is always sucessful.
+		 */
+		smp_call_function_single(event->cpu,
+					 __perf_event_remove_from_context,
+					 event, 1);
+		return;
+	}
+
+retry:
+	task_oncpu_function_call(task, __perf_event_remove_from_context,
+				 event);
+
+	spin_lock_irq(&ctx->lock);
+	/*
+	 * If the context is active we need to retry the smp call.
+	 */
+	if (ctx->nr_active && !list_empty(&event->group_entry)) {
+		spin_unlock_irq(&ctx->lock);
+		goto retry;
+	}
+
+	/*
+	 * The lock prevents that this context is scheduled in so we
+	 * can remove the event safely, if the call above did not
+	 * succeed.
+	 */
+	if (!list_empty(&event->group_entry)) {
+		list_del_event(event, ctx);
+	}
+	spin_unlock_irq(&ctx->lock);
+}
+
+static inline u64 perf_clock(void)
+{
+	return cpu_clock(smp_processor_id());
+}
+
+/*
+ * Update the record of the current time in a context.
+ */
+static void update_context_time(struct perf_event_context *ctx)
+{
+	u64 now = perf_clock();
+
+	ctx->time += now - ctx->timestamp;
+	ctx->timestamp = now;
+}
+
+/*
+ * Update the total_time_enabled and total_time_running fields for a event.
+ */
+static void update_event_times(struct perf_event *event)
+{
+	struct perf_event_context *ctx = event->ctx;
+	u64 run_end;
+
+	if (event->state < PERF_EVENT_STATE_INACTIVE ||
+	    event->group_leader->state < PERF_EVENT_STATE_INACTIVE)
+		return;
+
+	event->total_time_enabled = ctx->time - event->tstamp_enabled;
+
+	if (event->state == PERF_EVENT_STATE_INACTIVE)
+		run_end = event->tstamp_stopped;
+	else
+		run_end = ctx->time;
+
+	event->total_time_running = run_end - event->tstamp_running;
+}
+
+/*
+ * Update total_time_enabled and total_time_running for all events in a group.
+ */
+static void update_group_times(struct perf_event *leader)
+{
+	struct perf_event *event;
+
+	update_event_times(leader);
+	list_for_each_entry(event, &leader->sibling_list, group_entry)
+		update_event_times(event);
+}
+
+/*
+ * Cross CPU call to disable a performance event
+ */
+static void __perf_event_disable(void *info)
+{
+	struct perf_event *event = info;
+	struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
+	struct perf_event_context *ctx = event->ctx;
+
+	/*
+	 * If this is a per-task event, need to check whether this
+	 * event's task is the current task on this cpu.
+	 */
+	if (ctx->task && cpuctx->task_ctx != ctx)
+		return;
+
+	spin_lock(&ctx->lock);
+
+	/*
+	 * If the event is on, turn it off.
+	 * If it is in error state, leave it in error state.
+	 */
+	if (event->state >= PERF_EVENT_STATE_INACTIVE) {
+		update_context_time(ctx);
+		update_group_times(event);
+		if (event == event->group_leader)
+			group_sched_out(event, cpuctx, ctx);
+		else
+			event_sched_out(event, cpuctx, ctx);
+		event->state = PERF_EVENT_STATE_OFF;
+	}
+
+	spin_unlock(&ctx->lock);
+}
+
+/*
+ * Disable a event.
+ *
+ * If event->ctx is a cloned context, callers must make sure that
+ * every task struct that event->ctx->task could possibly point to
+ * remains valid.  This condition is satisifed when called through
+ * perf_event_for_each_child or perf_event_for_each because they
+ * hold the top-level event's child_mutex, so any descendant that
+ * goes to exit will block in sync_child_event.
+ * When called from perf_pending_event it's OK because event->ctx
+ * is the current context on this CPU and preemption is disabled,
+ * hence we can't get into perf_event_task_sched_out for this context.
+ */
+static void perf_event_disable(struct perf_event *event)
+{
+	struct perf_event_context *ctx = event->ctx;
+	struct task_struct *task = ctx->task;
+
+	if (!task) {
+		/*
+		 * Disable the event on the cpu that it's on
+		 */
+		smp_call_function_single(event->cpu, __perf_event_disable,
+					 event, 1);
+		return;
+	}
+
+ retry:
+	task_oncpu_function_call(task, __perf_event_disable, event);
+
+	spin_lock_irq(&ctx->lock);
+	/*
+	 * If the event is still active, we need to retry the cross-call.
+	 */
+	if (event->state == PERF_EVENT_STATE_ACTIVE) {
+		spin_unlock_irq(&ctx->lock);
+		goto retry;
+	}
+
+	/*
+	 * Since we have the lock this context can't be scheduled
+	 * in, so we can change the state safely.
+	 */
+	if (event->state == PERF_EVENT_STATE_INACTIVE) {
+		update_group_times(event);
+		event->state = PERF_EVENT_STATE_OFF;
+	}
+
+	spin_unlock_irq(&ctx->lock);
+}
+
+static int
+event_sched_in(struct perf_event *event,
+		 struct perf_cpu_context *cpuctx,
+		 struct perf_event_context *ctx,
+		 int cpu)
+{
+	if (event->state <= PERF_EVENT_STATE_OFF)
+		return 0;
+
+	event->state = PERF_EVENT_STATE_ACTIVE;
+	event->oncpu = cpu;	/* TODO: put 'cpu' into cpuctx->cpu */
+	/*
+	 * The new state must be visible before we turn it on in the hardware:
+	 */
+	smp_wmb();
+
+	if (event->pmu->enable(event)) {
+		event->state = PERF_EVENT_STATE_INACTIVE;
+		event->oncpu = -1;
+		return -EAGAIN;
+	}
+
+	event->tstamp_running += ctx->time - event->tstamp_stopped;
+
+	if (!is_software_event(event))
+		cpuctx->active_oncpu++;
+	ctx->nr_active++;
+
+	if (event->attr.exclusive)
+		cpuctx->exclusive = 1;
+
+	return 0;
+}
+
+static int
+group_sched_in(struct perf_event *group_event,
+	       struct perf_cpu_context *cpuctx,
+	       struct perf_event_context *ctx,
+	       int cpu)
+{
+	struct perf_event *event, *partial_group;
+	int ret;
+
+	if (group_event->state == PERF_EVENT_STATE_OFF)
+		return 0;
+
+	ret = hw_perf_group_sched_in(group_event, cpuctx, ctx, cpu);
+	if (ret)
+		return ret < 0 ? ret : 0;
+
+	if (event_sched_in(group_event, cpuctx, ctx, cpu))
+		return -EAGAIN;
+
+	/*
+	 * Schedule in siblings as one group (if any):
+	 */
+	list_for_each_entry(event, &group_event->sibling_list, group_entry) {
+		if (event_sched_in(event, cpuctx, ctx, cpu)) {
+			partial_group = event;
+			goto group_error;
+		}
+	}
+
+	return 0;
+
+group_error:
+	/*
+	 * Groups can be scheduled in as one unit only, so undo any
+	 * partial group before returning:
+	 */
+	list_for_each_entry(event, &group_event->sibling_list, group_entry) {
+		if (event == partial_group)
+			break;
+		event_sched_out(event, cpuctx, ctx);
+	}
+	event_sched_out(group_event, cpuctx, ctx);
+
+	return -EAGAIN;
+}
+
+/*
+ * Return 1 for a group consisting entirely of software events,
+ * 0 if the group contains any hardware events.
+ */
+static int is_software_only_group(struct perf_event *leader)
+{
+	struct perf_event *event;
+
+	if (!is_software_event(leader))
+		return 0;
+
+	list_for_each_entry(event, &leader->sibling_list, group_entry)
+		if (!is_software_event(event))
+			return 0;
+
+	return 1;
+}
+
+/*
+ * Work out whether we can put this event group on the CPU now.
+ */
+static int group_can_go_on(struct perf_event *event,
+			   struct perf_cpu_context *cpuctx,
+			   int can_add_hw)
+{
+	/*
+	 * Groups consisting entirely of software events can always go on.
+	 */
+	if (is_software_only_group(event))
+		return 1;
+	/*
+	 * If an exclusive group is already on, no other hardware
+	 * events can go on.
+	 */
+	if (cpuctx->exclusive)
+		return 0;
+	/*
+	 * If this group is exclusive and there are already
+	 * events on the CPU, it can't go on.
+	 */
+	if (event->attr.exclusive && cpuctx->active_oncpu)
+		return 0;
+	/*
+	 * Otherwise, try to add it if all previous groups were able
+	 * to go on.
+	 */
+	return can_add_hw;
+}
+
+static void add_event_to_ctx(struct perf_event *event,
+			       struct perf_event_context *ctx)
+{
+	list_add_event(event, ctx);
+	event->tstamp_enabled = ctx->time;
+	event->tstamp_running = ctx->time;
+	event->tstamp_stopped = ctx->time;
+}
+
+/*
+ * Cross CPU call to install and enable a performance event
+ *
+ * Must be called with ctx->mutex held
+ */
+static void __perf_install_in_context(void *info)
+{
+	struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
+	struct perf_event *event = info;
+	struct perf_event_context *ctx = event->ctx;
+	struct perf_event *leader = event->group_leader;
+	int cpu = smp_processor_id();
+	int err;
+
+	/*
+	 * If this is a task context, we need to check whether it is
+	 * the current task context of this cpu. If not it has been
+	 * scheduled out before the smp call arrived.
+	 * Or possibly this is the right context but it isn't
+	 * on this cpu because it had no events.
+	 */
+	if (ctx->task && cpuctx->task_ctx != ctx) {
+		if (cpuctx->task_ctx || ctx->task != current)
+			return;
+		cpuctx->task_ctx = ctx;
+	}
+
+	spin_lock(&ctx->lock);
+	ctx->is_active = 1;
+	update_context_time(ctx);
+
+	/*
+	 * Protect the list operation against NMI by disabling the
+	 * events on a global level. NOP for non NMI based events.
+	 */
+	perf_disable();
+
+	add_event_to_ctx(event, ctx);
+
+	/*
+	 * Don't put the event on if it is disabled or if
+	 * it is in a group and the group isn't on.
+	 */
+	if (event->state != PERF_EVENT_STATE_INACTIVE ||
+	    (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE))
+		goto unlock;
+
+	/*
+	 * An exclusive event can't go on if there are already active
+	 * hardware events, and no hardware event can go on if there
+	 * is already an exclusive event on.
+	 */
+	if (!group_can_go_on(event, cpuctx, 1))
+		err = -EEXIST;
+	else
+		err = event_sched_in(event, cpuctx, ctx, cpu);
+
+	if (err) {
+		/*
+		 * This event couldn't go on.  If it is in a group
+		 * then we have to pull the whole group off.
+		 * If the event group is pinned then put it in error state.
+		 */
+		if (leader != event)
+			group_sched_out(leader, cpuctx, ctx);
+		if (leader->attr.pinned) {
+			update_group_times(leader);
+			leader->state = PERF_EVENT_STATE_ERROR;
+		}
+	}
+
+	if (!err && !ctx->task && cpuctx->max_pertask)
+		cpuctx->max_pertask--;
+
+ unlock:
+	perf_enable();
+
+	spin_unlock(&ctx->lock);
+}
+
+/*
+ * Attach a performance event to a context
+ *
+ * First we add the event to the list with the hardware enable bit
+ * in event->hw_config cleared.
+ *
+ * If the event is attached to a task which is on a CPU we use a smp
+ * call to enable it in the task context. The task might have been
+ * scheduled away, but we check this in the smp call again.
+ *
+ * Must be called with ctx->mutex held.
+ */
+static void
+perf_install_in_context(struct perf_event_context *ctx,
+			struct perf_event *event,
+			int cpu)
+{
+	struct task_struct *task = ctx->task;
+
+	if (!task) {
+		/*
+		 * Per cpu events are installed via an smp call and
+		 * the install is always sucessful.
+		 */
+		smp_call_function_single(cpu, __perf_install_in_context,
+					 event, 1);
+		return;
+	}
+
+retry:
+	task_oncpu_function_call(task, __perf_install_in_context,
+				 event);
+
+	spin_lock_irq(&ctx->lock);
+	/*
+	 * we need to retry the smp call.
+	 */
+	if (ctx->is_active && list_empty(&event->group_entry)) {
+		spin_unlock_irq(&ctx->lock);
+		goto retry;
+	}
+
+	/*
+	 * The lock prevents that this context is scheduled in so we
+	 * can add the event safely, if it the call above did not
+	 * succeed.
+	 */
+	if (list_empty(&event->group_entry))
+		add_event_to_ctx(event, ctx);
+	spin_unlock_irq(&ctx->lock);
+}
+
+/*
+ * Put a event into inactive state and update time fields.
+ * Enabling the leader of a group effectively enables all
+ * the group members that aren't explicitly disabled, so we
+ * have to update their ->tstamp_enabled also.
+ * Note: this works for group members as well as group leaders
+ * since the non-leader members' sibling_lists will be empty.
+ */
+static void __perf_event_mark_enabled(struct perf_event *event,
+					struct perf_event_context *ctx)
+{
+	struct perf_event *sub;
+
+	event->state = PERF_EVENT_STATE_INACTIVE;
+	event->tstamp_enabled = ctx->time - event->total_time_enabled;
+	list_for_each_entry(sub, &event->sibling_list, group_entry)
+		if (sub->state >= PERF_EVENT_STATE_INACTIVE)
+			sub->tstamp_enabled =
+				ctx->time - sub->total_time_enabled;
+}
+
+/*
+ * Cross CPU call to enable a performance event
+ */
+static void __perf_event_enable(void *info)
+{
+	struct perf_event *event = info;
+	struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
+	struct perf_event_context *ctx = event->ctx;
+	struct perf_event *leader = event->group_leader;
+	int err;
+
+	/*
+	 * If this is a per-task event, need to check whether this
+	 * event's task is the current task on this cpu.
+	 */
+	if (ctx->task && cpuctx->task_ctx != ctx) {
+		if (cpuctx->task_ctx || ctx->task != current)
+			return;
+		cpuctx->task_ctx = ctx;
+	}
+
+	spin_lock(&ctx->lock);
+	ctx->is_active = 1;
+	update_context_time(ctx);
+
+	if (event->state >= PERF_EVENT_STATE_INACTIVE)
+		goto unlock;
+	__perf_event_mark_enabled(event, ctx);
+
+	/*
+	 * If the event is in a group and isn't the group leader,
+	 * then don't put it on unless the group is on.
+	 */
+	if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE)
+		goto unlock;
+
+	if (!group_can_go_on(event, cpuctx, 1)) {
+		err = -EEXIST;
+	} else {
+		perf_disable();
+		if (event == leader)
+			err = group_sched_in(event, cpuctx, ctx,
+					     smp_processor_id());
+		else
+			err = event_sched_in(event, cpuctx, ctx,
+					       smp_processor_id());
+		perf_enable();
+	}
+
+	if (err) {
+		/*
+		 * If this event can't go on and it's part of a
+		 * group, then the whole group has to come off.
+		 */
+		if (leader != event)
+			group_sched_out(leader, cpuctx, ctx);
+		if (leader->attr.pinned) {
+			update_group_times(leader);
+			leader->state = PERF_EVENT_STATE_ERROR;
+		}
+	}
+
+ unlock:
+	spin_unlock(&ctx->lock);
+}
+
+/*
+ * Enable a event.
+ *
+ * If event->ctx is a cloned context, callers must make sure that
+ * every task struct that event->ctx->task could possibly point to
+ * remains valid.  This condition is satisfied when called through
+ * perf_event_for_each_child or perf_event_for_each as described
+ * for perf_event_disable.
+ */
+static void perf_event_enable(struct perf_event *event)
+{
+	struct perf_event_context *ctx = event->ctx;
+	struct task_struct *task = ctx->task;
+
+	if (!task) {
+		/*
+		 * Enable the event on the cpu that it's on
+		 */
+		smp_call_function_single(event->cpu, __perf_event_enable,
+					 event, 1);
+		return;
+	}
+
+	spin_lock_irq(&ctx->lock);
+	if (event->state >= PERF_EVENT_STATE_INACTIVE)
+		goto out;
+
+	/*
+	 * If the event is in error state, clear that first.
+	 * That way, if we see the event in error state below, we
+	 * know that it has gone back into error state, as distinct
+	 * from the task having been scheduled away before the
+	 * cross-call arrived.
+	 */
+	if (event->state == PERF_EVENT_STATE_ERROR)
+		event->state = PERF_EVENT_STATE_OFF;
+
+ retry:
+	spin_unlock_irq(&ctx->lock);
+	task_oncpu_function_call(task, __perf_event_enable, event);
+
+	spin_lock_irq(&ctx->lock);
+
+	/*
+	 * If the context is active and the event is still off,
+	 * we need to retry the cross-call.
+	 */
+	if (ctx->is_active && event->state == PERF_EVENT_STATE_OFF)
+		goto retry;
+
+	/*
+	 * Since we have the lock this context can't be scheduled
+	 * in, so we can change the state safely.
+	 */
+	if (event->state == PERF_EVENT_STATE_OFF)
+		__perf_event_mark_enabled(event, ctx);
+
+ out:
+	spin_unlock_irq(&ctx->lock);
+}
+
+static int perf_event_refresh(struct perf_event *event, int refresh)
+{
+	/*
+	 * not supported on inherited events
+	 */
+	if (event->attr.inherit)
+		return -EINVAL;
+
+	atomic_add(refresh, &event->event_limit);
+	perf_event_enable(event);
+
+	return 0;
+}
+
+void __perf_event_sched_out(struct perf_event_context *ctx,
+			      struct perf_cpu_context *cpuctx)
+{
+	struct perf_event *event;
+
+	spin_lock(&ctx->lock);
+	ctx->is_active = 0;
+	if (likely(!ctx->nr_events))
+		goto out;
+	update_context_time(ctx);
+
+	perf_disable();
+	if (ctx->nr_active)
+		list_for_each_entry(event, &ctx->group_list, group_entry)
+			group_sched_out(event, cpuctx, ctx);
+
+	perf_enable();
+ out:
+	spin_unlock(&ctx->lock);
+}
+
+/*
+ * Test whether two contexts are equivalent, i.e. whether they
+ * have both been cloned from the same version of the same context
+ * and they both have the same number of enabled events.
+ * If the number of enabled events is the same, then the set
+ * of enabled events should be the same, because these are both
+ * inherited contexts, therefore we can't access individual events
+ * in them directly with an fd; we can only enable/disable all
+ * events via prctl, or enable/disable all events in a family
+ * via ioctl, which will have the same effect on both contexts.
+ */
+static int context_equiv(struct perf_event_context *ctx1,
+			 struct perf_event_context *ctx2)
+{
+	return ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx
+		&& ctx1->parent_gen == ctx2->parent_gen
+		&& !ctx1->pin_count && !ctx2->pin_count;
+}
+
+static void __perf_event_read(void *event);
+
+static void __perf_event_sync_stat(struct perf_event *event,
+				     struct perf_event *next_event)
+{
+	u64 value;
+
+	if (!event->attr.inherit_stat)
+		return;
+
+	/*
+	 * Update the event value, we cannot use perf_event_read()
+	 * because we're in the middle of a context switch and have IRQs
+	 * disabled, which upsets smp_call_function_single(), however
+	 * we know the event must be on the current CPU, therefore we
+	 * don't need to use it.
+	 */
+	switch (event->state) {
+	case PERF_EVENT_STATE_ACTIVE:
+		__perf_event_read(event);
+		break;
+
+	case PERF_EVENT_STATE_INACTIVE:
+		update_event_times(event);
+		break;
+
+	default:
+		break;
+	}
+
+	/*
+	 * In order to keep per-task stats reliable we need to flip the event
+	 * values when we flip the contexts.
+	 */
+	value = atomic64_read(&next_event->count);
+	value = atomic64_xchg(&event->count, value);
+	atomic64_set(&next_event->count, value);
+
+	swap(event->total_time_enabled, next_event->total_time_enabled);
+	swap(event->total_time_running, next_event->total_time_running);
+
+	/*
+	 * Since we swizzled the values, update the user visible data too.
+	 */
+	perf_event_update_userpage(event);
+	perf_event_update_userpage(next_event);
+}
+
+#define list_next_entry(pos, member) \
+	list_entry(pos->member.next, typeof(*pos), member)
+
+static void perf_event_sync_stat(struct perf_event_context *ctx,
+				   struct perf_event_context *next_ctx)
+{
+	struct perf_event *event, *next_event;
+
+	if (!ctx->nr_stat)
+		return;
+
+	event = list_first_entry(&ctx->event_list,
+				   struct perf_event, event_entry);
+
+	next_event = list_first_entry(&next_ctx->event_list,
+					struct perf_event, event_entry);
+
+	while (&event->event_entry != &ctx->event_list &&
+	       &next_event->event_entry != &next_ctx->event_list) {
+
+		__perf_event_sync_stat(event, next_event);
+
+		event = list_next_entry(event, event_entry);
+		next_event = list_next_entry(next_event, event_entry);
+	}
+}
+
+/*
+ * Called from scheduler to remove the events of the current task,
+ * with interrupts disabled.
+ *
+ * We stop each event and update the event value in event->count.
+ *
+ * This does not protect us against NMI, but disable()
+ * sets the disabled bit in the control field of event _before_
+ * accessing the event control register. If a NMI hits, then it will
+ * not restart the event.
+ */
+void perf_event_task_sched_out(struct task_struct *task,
+				 struct task_struct *next, int cpu)
+{
+	struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu);
+	struct perf_event_context *ctx = task->perf_event_ctxp;
+	struct perf_event_context *next_ctx;
+	struct perf_event_context *parent;
+	struct pt_regs *regs;
+	int do_switch = 1;
+
+	regs = task_pt_regs(task);
+	perf_sw_event(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, 1, regs, 0);
+
+	if (likely(!ctx || !cpuctx->task_ctx))
+		return;
+
+	update_context_time(ctx);
+
+	rcu_read_lock();
+	parent = rcu_dereference(ctx->parent_ctx);
+	next_ctx = next->perf_event_ctxp;
+	if (parent && next_ctx &&
+	    rcu_dereference(next_ctx->parent_ctx) == parent) {
+		/*
+		 * Looks like the two contexts are clones, so we might be
+		 * able to optimize the context switch.  We lock both
+		 * contexts and check that they are clones under the
+		 * lock (including re-checking that neither has been
+		 * uncloned in the meantime).  It doesn't matter which
+		 * order we take the locks because no other cpu could
+		 * be trying to lock both of these tasks.
+		 */
+		spin_lock(&ctx->lock);
+		spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING);
+		if (context_equiv(ctx, next_ctx)) {
+			/*
+			 * XXX do we need a memory barrier of sorts
+			 * wrt to rcu_dereference() of perf_event_ctxp
+			 */
+			task->perf_event_ctxp = next_ctx;
+			next->perf_event_ctxp = ctx;
+			ctx->task = next;
+			next_ctx->task = task;
+			do_switch = 0;
+
+			perf_event_sync_stat(ctx, next_ctx);
+		}
+		spin_unlock(&next_ctx->lock);
+		spin_unlock(&ctx->lock);
+	}
+	rcu_read_unlock();
+
+	if (do_switch) {
+		__perf_event_sched_out(ctx, cpuctx);
+		cpuctx->task_ctx = NULL;
+	}
+}
+
+/*
+ * Called with IRQs disabled
+ */
+static void __perf_event_task_sched_out(struct perf_event_context *ctx)
+{
+	struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
+
+	if (!cpuctx->task_ctx)
+		return;
+
+	if (WARN_ON_ONCE(ctx != cpuctx->task_ctx))
+		return;
+
+	__perf_event_sched_out(ctx, cpuctx);
+	cpuctx->task_ctx = NULL;
+}
+
+/*
+ * Called with IRQs disabled
+ */
+static void perf_event_cpu_sched_out(struct perf_cpu_context *cpuctx)
+{
+	__perf_event_sched_out(&cpuctx->ctx, cpuctx);
+}
+
+static void
+__perf_event_sched_in(struct perf_event_context *ctx,
+			struct perf_cpu_context *cpuctx, int cpu)
+{
+	struct perf_event *event;
+	int can_add_hw = 1;
+
+	spin_lock(&ctx->lock);
+	ctx->is_active = 1;
+	if (likely(!ctx->nr_events))
+		goto out;
+
+	ctx->timestamp = perf_clock();
+
+	perf_disable();
+
+	/*
+	 * First go through the list and put on any pinned groups
+	 * in order to give them the best chance of going on.
+	 */
+	list_for_each_entry(event, &ctx->group_list, group_entry) {
+		if (event->state <= PERF_EVENT_STATE_OFF ||
+		    !event->attr.pinned)
+			continue;
+		if (event->cpu != -1 && event->cpu != cpu)
+			continue;
+
+		if (group_can_go_on(event, cpuctx, 1))
+			group_sched_in(event, cpuctx, ctx, cpu);
+
+		/*
+		 * If this pinned group hasn't been scheduled,
+		 * put it in error state.
+		 */
+		if (event->state == PERF_EVENT_STATE_INACTIVE) {
+			update_group_times(event);
+			event->state = PERF_EVENT_STATE_ERROR;
+		}
+	}
+
+	list_for_each_entry(event, &ctx->group_list, group_entry) {
+		/*
+		 * Ignore events in OFF or ERROR state, and
+		 * ignore pinned events since we did them already.
+		 */
+		if (event->state <= PERF_EVENT_STATE_OFF ||
+		    event->attr.pinned)
+			continue;
+
+		/*
+		 * Listen to the 'cpu' scheduling filter constraint
+		 * of events:
+		 */
+		if (event->cpu != -1 && event->cpu != cpu)
+			continue;
+
+		if (group_can_go_on(event, cpuctx, can_add_hw))
+			if (group_sched_in(event, cpuctx, ctx, cpu))
+				can_add_hw = 0;
+	}
+	perf_enable();
+ out:
+	spin_unlock(&ctx->lock);
+}
+
+/*
+ * Called from scheduler to add the events of the current task
+ * with interrupts disabled.
+ *
+ * We restore the event value and then enable it.
+ *
+ * This does not protect us against NMI, but enable()
+ * sets the enabled bit in the control field of event _before_
+ * accessing the event control register. If a NMI hits, then it will
+ * keep the event running.
+ */
+void perf_event_task_sched_in(struct task_struct *task, int cpu)
+{
+	struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu);
+	struct perf_event_context *ctx = task->perf_event_ctxp;
+
+	if (likely(!ctx))
+		return;
+	if (cpuctx->task_ctx == ctx)
+		return;
+	__perf_event_sched_in(ctx, cpuctx, cpu);
+	cpuctx->task_ctx = ctx;
+}
+
+static void perf_event_cpu_sched_in(struct perf_cpu_context *cpuctx, int cpu)
+{
+	struct perf_event_context *ctx = &cpuctx->ctx;
+
+	__perf_event_sched_in(ctx, cpuctx, cpu);
+}
+
+#define MAX_INTERRUPTS (~0ULL)
+
+static void perf_log_throttle(struct perf_event *event, int enable);
+
+static void perf_adjust_period(struct perf_event *event, u64 events)
+{
+	struct hw_perf_event *hwc = &event->hw;
+	u64 period, sample_period;
+	s64 delta;
+
+	events *= hwc->sample_period;
+	period = div64_u64(events, event->attr.sample_freq);
+
+	delta = (s64)(period - hwc->sample_period);
+	delta = (delta + 7) / 8; /* low pass filter */
+
+	sample_period = hwc->sample_period + delta;
+
+	if (!sample_period)
+		sample_period = 1;
+
+	hwc->sample_period = sample_period;
+}
+
+static void perf_ctx_adjust_freq(struct perf_event_context *ctx)
+{
+	struct perf_event *event;
+	struct hw_perf_event *hwc;
+	u64 interrupts, freq;
+
+	spin_lock(&ctx->lock);
+	list_for_each_entry(event, &ctx->group_list, group_entry) {
+		if (event->state != PERF_EVENT_STATE_ACTIVE)
+			continue;
+
+		hwc = &event->hw;
+
+		interrupts = hwc->interrupts;
+		hwc->interrupts = 0;
+
+		/*
+		 * unthrottle events on the tick
+		 */
+		if (interrupts == MAX_INTERRUPTS) {
+			perf_log_throttle(event, 1);
+			event->pmu->unthrottle(event);
+			interrupts = 2*sysctl_perf_event_sample_rate/HZ;
+		}
+
+		if (!event->attr.freq || !event->attr.sample_freq)
+			continue;
+
+		/*
+		 * if the specified freq < HZ then we need to skip ticks
+		 */
+		if (event->attr.sample_freq < HZ) {
+			freq = event->attr.sample_freq;
+
+			hwc->freq_count += freq;
+			hwc->freq_interrupts += interrupts;
+
+			if (hwc->freq_count < HZ)
+				continue;
+
+			interrupts = hwc->freq_interrupts;
+			hwc->freq_interrupts = 0;
+			hwc->freq_count -= HZ;
+		} else
+			freq = HZ;
+
+		perf_adjust_period(event, freq * interrupts);
+
+		/*
+		 * In order to avoid being stalled by an (accidental) huge
+		 * sample period, force reset the sample period if we didn't
+		 * get any events in this freq period.
+		 */
+		if (!interrupts) {
+			perf_disable();
+			event->pmu->disable(event);
+			atomic64_set(&hwc->period_left, 0);
+			event->pmu->enable(event);
+			perf_enable();
+		}
+	}
+	spin_unlock(&ctx->lock);
+}
+
+/*
+ * Round-robin a context's events:
+ */
+static void rotate_ctx(struct perf_event_context *ctx)
+{
+	struct perf_event *event;
+
+	if (!ctx->nr_events)
+		return;
+
+	spin_lock(&ctx->lock);
+	/*
+	 * Rotate the first entry last (works just fine for group events too):
+	 */
+	perf_disable();
+	list_for_each_entry(event, &ctx->group_list, group_entry) {
+		list_move_tail(&event->group_entry, &ctx->group_list);
+		break;
+	}
+	perf_enable();
+
+	spin_unlock(&ctx->lock);
+}
+
+void perf_event_task_tick(struct task_struct *curr, int cpu)
+{
+	struct perf_cpu_context *cpuctx;
+	struct perf_event_context *ctx;
+
+	if (!atomic_read(&nr_events))
+		return;
+
+	cpuctx = &per_cpu(perf_cpu_context, cpu);
+	ctx = curr->perf_event_ctxp;
+
+	perf_ctx_adjust_freq(&cpuctx->ctx);
+	if (ctx)
+		perf_ctx_adjust_freq(ctx);
+
+	perf_event_cpu_sched_out(cpuctx);
+	if (ctx)
+		__perf_event_task_sched_out(ctx);
+
+	rotate_ctx(&cpuctx->ctx);
+	if (ctx)
+		rotate_ctx(ctx);
+
+	perf_event_cpu_sched_in(cpuctx, cpu);
+	if (ctx)
+		perf_event_task_sched_in(curr, cpu);
+}
+
+/*
+ * Enable all of a task's events that have been marked enable-on-exec.
+ * This expects task == current.
+ */
+static void perf_event_enable_on_exec(struct task_struct *task)
+{
+	struct perf_event_context *ctx;
+	struct perf_event *event;
+	unsigned long flags;
+	int enabled = 0;
+
+	local_irq_save(flags);
+	ctx = task->perf_event_ctxp;
+	if (!ctx || !ctx->nr_events)
+		goto out;
+
+	__perf_event_task_sched_out(ctx);
+
+	spin_lock(&ctx->lock);
+
+	list_for_each_entry(event, &ctx->group_list, group_entry) {
+		if (!event->attr.enable_on_exec)
+			continue;
+		event->attr.enable_on_exec = 0;
+		if (event->state >= PERF_EVENT_STATE_INACTIVE)
+			continue;
+		__perf_event_mark_enabled(event, ctx);
+		enabled = 1;
+	}
+
+	/*
+	 * Unclone this context if we enabled any event.
+	 */
+	if (enabled)
+		unclone_ctx(ctx);
+
+	spin_unlock(&ctx->lock);
+
+	perf_event_task_sched_in(task, smp_processor_id());
+ out:
+	local_irq_restore(flags);
+}
+
+/*
+ * Cross CPU call to read the hardware event
+ */
+static void __perf_event_read(void *info)
+{
+	struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
+	struct perf_event *event = info;
+	struct perf_event_context *ctx = event->ctx;
+	unsigned long flags;
+
+	/*
+	 * If this is a task context, we need to check whether it is
+	 * the current task context of this cpu.  If not it has been
+	 * scheduled out before the smp call arrived.  In that case
+	 * event->count would have been updated to a recent sample
+	 * when the event was scheduled out.
+	 */
+	if (ctx->task && cpuctx->task_ctx != ctx)
+		return;
+
+	local_irq_save(flags);
+	if (ctx->is_active)
+		update_context_time(ctx);
+	event->pmu->read(event);
+	update_event_times(event);
+	local_irq_restore(flags);
+}
+
+static u64 perf_event_read(struct perf_event *event)
+{
+	/*
+	 * If event is enabled and currently active on a CPU, update the
+	 * value in the event structure:
+	 */
+	if (event->state == PERF_EVENT_STATE_ACTIVE) {
+		smp_call_function_single(event->oncpu,
+					 __perf_event_read, event, 1);
+	} else if (event->state == PERF_EVENT_STATE_INACTIVE) {
+		update_event_times(event);
+	}
+
+	return atomic64_read(&event->count);
+}
+
+/*
+ * Initialize the perf_event context in a task_struct:
+ */
+static void
+__perf_event_init_context(struct perf_event_context *ctx,
+			    struct task_struct *task)
+{
+	memset(ctx, 0, sizeof(*ctx));
+	spin_lock_init(&ctx->lock);
+	mutex_init(&ctx->mutex);
+	INIT_LIST_HEAD(&ctx->group_list);
+	INIT_LIST_HEAD(&ctx->event_list);
+	atomic_set(&ctx->refcount, 1);
+	ctx->task = task;
+}
+
+static struct perf_event_context *find_get_context(pid_t pid, int cpu)
+{
+	struct perf_event_context *ctx;
+	struct perf_cpu_context *cpuctx;
+	struct task_struct *task;
+	unsigned long flags;
+	int err;
+
+	/*
+	 * If cpu is not a wildcard then this is a percpu event:
+	 */
+	if (cpu != -1) {
+		/* Must be root to operate on a CPU event: */
+		if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN))
+			return ERR_PTR(-EACCES);
+
+		if (cpu < 0 || cpu > num_possible_cpus())
+			return ERR_PTR(-EINVAL);
+
+		/*
+		 * We could be clever and allow to attach a event to an
+		 * offline CPU and activate it when the CPU comes up, but
+		 * that's for later.
+		 */
+		if (!cpu_isset(cpu, cpu_online_map))
+			return ERR_PTR(-ENODEV);
+
+		cpuctx = &per_cpu(perf_cpu_context, cpu);
+		ctx = &cpuctx->ctx;
+		get_ctx(ctx);
+
+		return ctx;
+	}
+
+	rcu_read_lock();
+	if (!pid)
+		task = current;
+	else
+		task = find_task_by_vpid(pid);
+	if (task)
+		get_task_struct(task);
+	rcu_read_unlock();
+
+	if (!task)
+		return ERR_PTR(-ESRCH);
+
+	/*
+	 * Can't attach events to a dying task.
+	 */
+	err = -ESRCH;
+	if (task->flags & PF_EXITING)
+		goto errout;
+
+	/* Reuse ptrace permission checks for now. */
+	err = -EACCES;
+	if (!ptrace_may_access(task, PTRACE_MODE_READ))
+		goto errout;
+
+ retry:
+	ctx = perf_lock_task_context(task, &flags);
+	if (ctx) {
+		unclone_ctx(ctx);
+		spin_unlock_irqrestore(&ctx->lock, flags);
+	}
+
+	if (!ctx) {
+		ctx = kmalloc(sizeof(struct perf_event_context), GFP_KERNEL);
+		err = -ENOMEM;
+		if (!ctx)
+			goto errout;
+		__perf_event_init_context(ctx, task);
+		get_ctx(ctx);
+		if (cmpxchg(&task->perf_event_ctxp, NULL, ctx)) {
+			/*
+			 * We raced with some other task; use
+			 * the context they set.
+			 */
+			kfree(ctx);
+			goto retry;
+		}
+		get_task_struct(task);
+	}
+
+	put_task_struct(task);
+	return ctx;
+
+ errout:
+	put_task_struct(task);
+	return ERR_PTR(err);
+}
+
+static void free_event_rcu(struct rcu_head *head)
+{
+	struct perf_event *event;
+
+	event = container_of(head, struct perf_event, rcu_head);
+	if (event->ns)
+		put_pid_ns(event->ns);
+	kfree(event);
+}
+
+static void perf_pending_sync(struct perf_event *event);
+
+static void free_event(struct perf_event *event)
+{
+	perf_pending_sync(event);
+
+	if (!event->parent) {
+		atomic_dec(&nr_events);
+		if (event->attr.mmap)
+			atomic_dec(&nr_mmap_events);
+		if (event->attr.comm)
+			atomic_dec(&nr_comm_events);
+		if (event->attr.task)
+			atomic_dec(&nr_task_events);
+	}
+
+	if (event->output) {
+		fput(event->output->filp);
+		event->output = NULL;
+	}
+
+	if (event->destroy)
+		event->destroy(event);
+
+	put_ctx(event->ctx);
+	call_rcu(&event->rcu_head, free_event_rcu);
+}
+
+/*
+ * Called when the last reference to the file is gone.
+ */
+static int perf_release(struct inode *inode, struct file *file)
+{
+	struct perf_event *event = file->private_data;
+	struct perf_event_context *ctx = event->ctx;
+
+	file->private_data = NULL;
+
+	WARN_ON_ONCE(ctx->parent_ctx);
+	mutex_lock(&ctx->mutex);
+	perf_event_remove_from_context(event);
+	mutex_unlock(&ctx->mutex);
+
+	mutex_lock(&event->owner->perf_event_mutex);
+	list_del_init(&event->owner_entry);
+	mutex_unlock(&event->owner->perf_event_mutex);
+	put_task_struct(event->owner);
+
+	free_event(event);
+
+	return 0;
+}
+
+static int perf_event_read_size(struct perf_event *event)
+{
+	int entry = sizeof(u64); /* value */
+	int size = 0;
+	int nr = 1;
+
+	if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
+		size += sizeof(u64);
+
+	if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
+		size += sizeof(u64);
+
+	if (event->attr.read_format & PERF_FORMAT_ID)
+		entry += sizeof(u64);
+
+	if (event->attr.read_format & PERF_FORMAT_GROUP) {
+		nr += event->group_leader->nr_siblings;
+		size += sizeof(u64);
+	}
+
+	size += entry * nr;
+
+	return size;
+}
+
+static u64 perf_event_read_value(struct perf_event *event)
+{
+	struct perf_event *child;
+	u64 total = 0;
+
+	total += perf_event_read(event);
+	list_for_each_entry(child, &event->child_list, child_list)
+		total += perf_event_read(child);
+
+	return total;
+}
+
+static int perf_event_read_entry(struct perf_event *event,
+				   u64 read_format, char __user *buf)
+{
+	int n = 0, count = 0;
+	u64 values[2];
+
+	values[n++] = perf_event_read_value(event);
+	if (read_format & PERF_FORMAT_ID)
+		values[n++] = primary_event_id(event);
+
+	count = n * sizeof(u64);
+
+	if (copy_to_user(buf, values, count))
+		return -EFAULT;
+
+	return count;
+}
+
+static int perf_event_read_group(struct perf_event *event,
+				   u64 read_format, char __user *buf)
+{
+	struct perf_event *leader = event->group_leader, *sub;
+	int n = 0, size = 0, err = -EFAULT;
+	u64 values[3];
+
+	values[n++] = 1 + leader->nr_siblings;
+	if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
+		values[n++] = leader->total_time_enabled +
+			atomic64_read(&leader->child_total_time_enabled);
+	}
+	if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
+		values[n++] = leader->total_time_running +
+			atomic64_read(&leader->child_total_time_running);
+	}
+
+	size = n * sizeof(u64);
+
+	if (copy_to_user(buf, values, size))
+		return -EFAULT;
+
+	err = perf_event_read_entry(leader, read_format, buf + size);
+	if (err < 0)
+		return err;
+
+	size += err;
+
+	list_for_each_entry(sub, &leader->sibling_list, group_entry) {
+		err = perf_event_read_entry(sub, read_format,
+				buf + size);
+		if (err < 0)
+			return err;
+
+		size += err;
+	}
+
+	return size;
+}
+
+static int perf_event_read_one(struct perf_event *event,
+				 u64 read_format, char __user *buf)
+{
+	u64 values[4];
+	int n = 0;
+
+	values[n++] = perf_event_read_value(event);
+	if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
+		values[n++] = event->total_time_enabled +
+			atomic64_read(&event->child_total_time_enabled);
+	}
+	if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
+		values[n++] = event->total_time_running +
+			atomic64_read(&event->child_total_time_running);
+	}
+	if (read_format & PERF_FORMAT_ID)
+		values[n++] = primary_event_id(event);
+
+	if (copy_to_user(buf, values, n * sizeof(u64)))
+		return -EFAULT;
+
+	return n * sizeof(u64);
+}
+
+/*
+ * Read the performance event - simple non blocking version for now
+ */
+static ssize_t
+perf_read_hw(struct perf_event *event, char __user *buf, size_t count)
+{
+	u64 read_format = event->attr.read_format;
+	int ret;
+
+	/*
+	 * Return end-of-file for a read on a event that is in
+	 * error state (i.e. because it was pinned but it couldn't be
+	 * scheduled on to the CPU at some point).
+	 */
+	if (event->state == PERF_EVENT_STATE_ERROR)
+		return 0;
+
+	if (count < perf_event_read_size(event))
+		return -ENOSPC;
+
+	WARN_ON_ONCE(event->ctx->parent_ctx);
+	mutex_lock(&event->child_mutex);
+	if (read_format & PERF_FORMAT_GROUP)
+		ret = perf_event_read_group(event, read_format, buf);
+	else
+		ret = perf_event_read_one(event, read_format, buf);
+	mutex_unlock(&event->child_mutex);
+
+	return ret;
+}
+
+static ssize_t
+perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
+{
+	struct perf_event *event = file->private_data;
+
+	return perf_read_hw(event, buf, count);
+}
+
+static unsigned int perf_poll(struct file *file, poll_table *wait)
+{
+	struct perf_event *event = file->private_data;
+	struct perf_mmap_data *data;
+	unsigned int events = POLL_HUP;
+
+	rcu_read_lock();
+	data = rcu_dereference(event->data);
+	if (data)
+		events = atomic_xchg(&data->poll, 0);
+	rcu_read_unlock();
+
+	poll_wait(file, &event->waitq, wait);
+
+	return events;
+}
+
+static void perf_event_reset(struct perf_event *event)
+{
+	(void)perf_event_read(event);
+	atomic64_set(&event->count, 0);
+	perf_event_update_userpage(event);
+}
+
+/*
+ * Holding the top-level event's child_mutex means that any
+ * descendant process that has inherited this event will block
+ * in sync_child_event if it goes to exit, thus satisfying the
+ * task existence requirements of perf_event_enable/disable.
+ */
+static void perf_event_for_each_child(struct perf_event *event,
+					void (*func)(struct perf_event *))
+{
+	struct perf_event *child;
+
+	WARN_ON_ONCE(event->ctx->parent_ctx);
+	mutex_lock(&event->child_mutex);
+	func(event);
+	list_for_each_entry(child, &event->child_list, child_list)
+		func(child);
+	mutex_unlock(&event->child_mutex);
+}
+
+static void perf_event_for_each(struct perf_event *event,
+				  void (*func)(struct perf_event *))
+{
+	struct perf_event_context *ctx = event->ctx;
+	struct perf_event *sibling;
+
+	WARN_ON_ONCE(ctx->parent_ctx);
+	mutex_lock(&ctx->mutex);
+	event = event->group_leader;
+
+	perf_event_for_each_child(event, func);
+	func(event);
+	list_for_each_entry(sibling, &event->sibling_list, group_entry)
+		perf_event_for_each_child(event, func);
+	mutex_unlock(&ctx->mutex);
+}
+
+static int perf_event_period(struct perf_event *event, u64 __user *arg)
+{
+	struct perf_event_context *ctx = event->ctx;
+	unsigned long size;
+	int ret = 0;
+	u64 value;
+
+	if (!event->attr.sample_period)
+		return -EINVAL;
+
+	size = copy_from_user(&value, arg, sizeof(value));
+	if (size != sizeof(value))
+		return -EFAULT;
+
+	if (!value)
+		return -EINVAL;
+
+	spin_lock_irq(&ctx->lock);
+	if (event->attr.freq) {
+		if (value > sysctl_perf_event_sample_rate) {
+			ret = -EINVAL;
+			goto unlock;
+		}
+
+		event->attr.sample_freq = value;
+	} else {
+		event->attr.sample_period = value;
+		event->hw.sample_period = value;
+	}
+unlock:
+	spin_unlock_irq(&ctx->lock);
+
+	return ret;
+}
+
+int perf_event_set_output(struct perf_event *event, int output_fd);
+
+static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	struct perf_event *event = file->private_data;
+	void (*func)(struct perf_event *);
+	u32 flags = arg;
+
+	switch (cmd) {
+	case PERF_EVENT_IOC_ENABLE:
+		func = perf_event_enable;
+		break;
+	case PERF_EVENT_IOC_DISABLE:
+		func = perf_event_disable;
+		break;
+	case PERF_EVENT_IOC_RESET:
+		func = perf_event_reset;
+		break;
+
+	case PERF_EVENT_IOC_REFRESH:
+		return perf_event_refresh(event, arg);
+
+	case PERF_EVENT_IOC_PERIOD:
+		return perf_event_period(event, (u64 __user *)arg);
+
+	case PERF_EVENT_IOC_SET_OUTPUT:
+		return perf_event_set_output(event, arg);
+
+	default:
+		return -ENOTTY;
+	}
+
+	if (flags & PERF_IOC_FLAG_GROUP)
+		perf_event_for_each(event, func);
+	else
+		perf_event_for_each_child(event, func);
+
+	return 0;
+}
+
+int perf_event_task_enable(void)
+{
+	struct perf_event *event;
+
+	mutex_lock(&current->perf_event_mutex);
+	list_for_each_entry(event, &current->perf_event_list, owner_entry)
+		perf_event_for_each_child(event, perf_event_enable);
+	mutex_unlock(&current->perf_event_mutex);
+
+	return 0;
+}
+
+int perf_event_task_disable(void)
+{
+	struct perf_event *event;
+
+	mutex_lock(&current->perf_event_mutex);
+	list_for_each_entry(event, &current->perf_event_list, owner_entry)
+		perf_event_for_each_child(event, perf_event_disable);
+	mutex_unlock(&current->perf_event_mutex);
+
+	return 0;
+}
+
+#ifndef PERF_EVENT_INDEX_OFFSET
+# define PERF_EVENT_INDEX_OFFSET 0
+#endif
+
+static int perf_event_index(struct perf_event *event)
+{
+	if (event->state != PERF_EVENT_STATE_ACTIVE)
+		return 0;
+
+	return event->hw.idx + 1 - PERF_EVENT_INDEX_OFFSET;
+}
+
+/*
+ * Callers need to ensure there can be no nesting of this function, otherwise
+ * the seqlock logic goes bad. We can not serialize this because the arch
+ * code calls this from NMI context.
+ */
+void perf_event_update_userpage(struct perf_event *event)
+{
+	struct perf_event_mmap_page *userpg;
+	struct perf_mmap_data *data;
+
+	rcu_read_lock();
+	data = rcu_dereference(event->data);
+	if (!data)
+		goto unlock;
+
+	userpg = data->user_page;
+
+	/*
+	 * Disable preemption so as to not let the corresponding user-space
+	 * spin too long if we get preempted.
+	 */
+	preempt_disable();
+	++userpg->lock;
+	barrier();
+	userpg->index = perf_event_index(event);
+	userpg->offset = atomic64_read(&event->count);
+	if (event->state == PERF_EVENT_STATE_ACTIVE)
+		userpg->offset -= atomic64_read(&event->hw.prev_count);
+
+	userpg->time_enabled = event->total_time_enabled +
+			atomic64_read(&event->child_total_time_enabled);
+
+	userpg->time_running = event->total_time_running +
+			atomic64_read(&event->child_total_time_running);
+
+	barrier();
+	++userpg->lock;
+	preempt_enable();
+unlock:
+	rcu_read_unlock();
+}
+
+static unsigned long perf_data_size(struct perf_mmap_data *data)
+{
+	return data->nr_pages << (PAGE_SHIFT + data->data_order);
+}
+
+#ifndef CONFIG_PERF_USE_VMALLOC
+
+/*
+ * Back perf_mmap() with regular GFP_KERNEL-0 pages.
+ */
+
+static struct page *
+perf_mmap_to_page(struct perf_mmap_data *data, unsigned long pgoff)
+{
+	if (pgoff > data->nr_pages)
+		return NULL;
+
+	if (pgoff == 0)
+		return virt_to_page(data->user_page);
+
+	return virt_to_page(data->data_pages[pgoff - 1]);
+}
+
+static struct perf_mmap_data *
+perf_mmap_data_alloc(struct perf_event *event, int nr_pages)
+{
+	struct perf_mmap_data *data;
+	unsigned long size;
+	int i;
+
+	WARN_ON(atomic_read(&event->mmap_count));
+
+	size = sizeof(struct perf_mmap_data);
+	size += nr_pages * sizeof(void *);
+
+	data = kzalloc(size, GFP_KERNEL);
+	if (!data)
+		goto fail;
+
+	data->user_page = (void *)get_zeroed_page(GFP_KERNEL);
+	if (!data->user_page)
+		goto fail_user_page;
+
+	for (i = 0; i < nr_pages; i++) {
+		data->data_pages[i] = (void *)get_zeroed_page(GFP_KERNEL);
+		if (!data->data_pages[i])
+			goto fail_data_pages;
+	}
+
+	data->data_order = 0;
+	data->nr_pages = nr_pages;
+
+	return data;
+
+fail_data_pages:
+	for (i--; i >= 0; i--)
+		free_page((unsigned long)data->data_pages[i]);
+
+	free_page((unsigned long)data->user_page);
+
+fail_user_page:
+	kfree(data);
+
+fail:
+	return NULL;
+}
+
+static void perf_mmap_free_page(unsigned long addr)
+{
+	struct page *page = virt_to_page((void *)addr);
+
+	page->mapping = NULL;
+	__free_page(page);
+}
+
+static void perf_mmap_data_free(struct perf_mmap_data *data)
+{
+	int i;
+
+	perf_mmap_free_page((unsigned long)data->user_page);
+	for (i = 0; i < data->nr_pages; i++)
+		perf_mmap_free_page((unsigned long)data->data_pages[i]);
+}
+
+#else
+
+/*
+ * Back perf_mmap() with vmalloc memory.
+ *
+ * Required for architectures that have d-cache aliasing issues.
+ */
+
+static struct page *
+perf_mmap_to_page(struct perf_mmap_data *data, unsigned long pgoff)
+{
+	if (pgoff > (1UL << data->data_order))
+		return NULL;
+
+	return vmalloc_to_page((void *)data->user_page + pgoff * PAGE_SIZE);
+}
+
+static void perf_mmap_unmark_page(void *addr)
+{
+	struct page *page = vmalloc_to_page(addr);
+
+	page->mapping = NULL;
+}
+
+static void perf_mmap_data_free_work(struct work_struct *work)
+{
+	struct perf_mmap_data *data;
+	void *base;
+	int i, nr;
+
+	data = container_of(work, struct perf_mmap_data, work);
+	nr = 1 << data->data_order;
+
+	base = data->user_page;
+	for (i = 0; i < nr + 1; i++)
+		perf_mmap_unmark_page(base + (i * PAGE_SIZE));
+
+	vfree(base);
+}
+
+static void perf_mmap_data_free(struct perf_mmap_data *data)
+{
+	schedule_work(&data->work);
+}
+
+static struct perf_mmap_data *
+perf_mmap_data_alloc(struct perf_event *event, int nr_pages)
+{
+	struct perf_mmap_data *data;
+	unsigned long size;
+	void *all_buf;
+
+	WARN_ON(atomic_read(&event->mmap_count));
+
+	size = sizeof(struct perf_mmap_data);
+	size += sizeof(void *);
+
+	data = kzalloc(size, GFP_KERNEL);
+	if (!data)
+		goto fail;
+
+	INIT_WORK(&data->work, perf_mmap_data_free_work);
+
+	all_buf = vmalloc_user((nr_pages + 1) * PAGE_SIZE);
+	if (!all_buf)
+		goto fail_all_buf;
+
+	data->user_page = all_buf;
+	data->data_pages[0] = all_buf + PAGE_SIZE;
+	data->data_order = ilog2(nr_pages);
+	data->nr_pages = 1;
+
+	return data;
+
+fail_all_buf:
+	kfree(data);
+
+fail:
+	return NULL;
+}
+
+#endif
+
+static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+	struct perf_event *event = vma->vm_file->private_data;
+	struct perf_mmap_data *data;
+	int ret = VM_FAULT_SIGBUS;
+
+	if (vmf->flags & FAULT_FLAG_MKWRITE) {
+		if (vmf->pgoff == 0)
+			ret = 0;
+		return ret;
+	}
+
+	rcu_read_lock();
+	data = rcu_dereference(event->data);
+	if (!data)
+		goto unlock;
+
+	if (vmf->pgoff && (vmf->flags & FAULT_FLAG_WRITE))
+		goto unlock;
+
+	vmf->page = perf_mmap_to_page(data, vmf->pgoff);
+	if (!vmf->page)
+		goto unlock;
+
+	get_page(vmf->page);
+	vmf->page->mapping = vma->vm_file->f_mapping;
+	vmf->page->index   = vmf->pgoff;
+
+	ret = 0;
+unlock:
+	rcu_read_unlock();
+
+	return ret;
+}
+
+static void
+perf_mmap_data_init(struct perf_event *event, struct perf_mmap_data *data)
+{
+	long max_size = perf_data_size(data);
+
+	atomic_set(&data->lock, -1);
+
+	if (event->attr.watermark) {
+		data->watermark = min_t(long, max_size,
+					event->attr.wakeup_watermark);
+	}
+
+	if (!data->watermark)
+		data->watermark = max_t(long, PAGE_SIZE, max_size / 2);
+
+
+	rcu_assign_pointer(event->data, data);
+}
+
+static void perf_mmap_data_free_rcu(struct rcu_head *rcu_head)
+{
+	struct perf_mmap_data *data;
+
+	data = container_of(rcu_head, struct perf_mmap_data, rcu_head);
+	perf_mmap_data_free(data);
+	kfree(data);
+}
+
+static void perf_mmap_data_release(struct perf_event *event)
+{
+	struct perf_mmap_data *data = event->data;
+
+	WARN_ON(atomic_read(&event->mmap_count));
+
+	rcu_assign_pointer(event->data, NULL);
+	call_rcu(&data->rcu_head, perf_mmap_data_free_rcu);
+}
+
+static void perf_mmap_open(struct vm_area_struct *vma)
+{
+	struct perf_event *event = vma->vm_file->private_data;
+
+	atomic_inc(&event->mmap_count);
+}
+
+static void perf_mmap_close(struct vm_area_struct *vma)
+{
+	struct perf_event *event = vma->vm_file->private_data;
+
+	WARN_ON_ONCE(event->ctx->parent_ctx);
+	if (atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex)) {
+		unsigned long size = perf_data_size(event->data);
+		struct user_struct *user = current_user();
+
+		atomic_long_sub((size >> PAGE_SHIFT) + 1, &user->locked_vm);
+		vma->vm_mm->locked_vm -= event->data->nr_locked;
+		perf_mmap_data_release(event);
+		mutex_unlock(&event->mmap_mutex);
+	}
+}
+
+static const struct vm_operations_struct perf_mmap_vmops = {
+	.open		= perf_mmap_open,
+	.close		= perf_mmap_close,
+	.fault		= perf_mmap_fault,
+	.page_mkwrite	= perf_mmap_fault,
+};
+
+static int perf_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	struct perf_event *event = file->private_data;
+	unsigned long user_locked, user_lock_limit;
+	struct user_struct *user = current_user();
+	unsigned long locked, lock_limit;
+	struct perf_mmap_data *data;
+	unsigned long vma_size;
+	unsigned long nr_pages;
+	long user_extra, extra;
+	int ret = 0;
+
+	if (!(vma->vm_flags & VM_SHARED))
+		return -EINVAL;
+
+	vma_size = vma->vm_end - vma->vm_start;
+	nr_pages = (vma_size / PAGE_SIZE) - 1;
+
+	/*
+	 * If we have data pages ensure they're a power-of-two number, so we
+	 * can do bitmasks instead of modulo.
+	 */
+	if (nr_pages != 0 && !is_power_of_2(nr_pages))
+		return -EINVAL;
+
+	if (vma_size != PAGE_SIZE * (1 + nr_pages))
+		return -EINVAL;
+
+	if (vma->vm_pgoff != 0)
+		return -EINVAL;
+
+	WARN_ON_ONCE(event->ctx->parent_ctx);
+	mutex_lock(&event->mmap_mutex);
+	if (event->output) {
+		ret = -EINVAL;
+		goto unlock;
+	}
+
+	if (atomic_inc_not_zero(&event->mmap_count)) {
+		if (nr_pages != event->data->nr_pages)
+			ret = -EINVAL;
+		goto unlock;
+	}
+
+	user_extra = nr_pages + 1;
+	user_lock_limit = sysctl_perf_event_mlock >> (PAGE_SHIFT - 10);
+
+	/*
+	 * Increase the limit linearly with more CPUs:
+	 */
+	user_lock_limit *= num_online_cpus();
+
+	user_locked = atomic_long_read(&user->locked_vm) + user_extra;
+
+	extra = 0;
+	if (user_locked > user_lock_limit)
+		extra = user_locked - user_lock_limit;
+
+	lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
+	lock_limit >>= PAGE_SHIFT;
+	locked = vma->vm_mm->locked_vm + extra;
+
+	if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() &&
+		!capable(CAP_IPC_LOCK)) {
+		ret = -EPERM;
+		goto unlock;
+	}
+
+	WARN_ON(event->data);
+
+	data = perf_mmap_data_alloc(event, nr_pages);
+	ret = -ENOMEM;
+	if (!data)
+		goto unlock;
+
+	ret = 0;
+	perf_mmap_data_init(event, data);
+
+	atomic_set(&event->mmap_count, 1);
+	atomic_long_add(user_extra, &user->locked_vm);
+	vma->vm_mm->locked_vm += extra;
+	event->data->nr_locked = extra;
+	if (vma->vm_flags & VM_WRITE)
+		event->data->writable = 1;
+
+unlock:
+	mutex_unlock(&event->mmap_mutex);
+
+	vma->vm_flags |= VM_RESERVED;
+	vma->vm_ops = &perf_mmap_vmops;
+
+	return ret;
+}
+
+static int perf_fasync(int fd, struct file *filp, int on)
+{
+	struct inode *inode = filp->f_path.dentry->d_inode;
+	struct perf_event *event = filp->private_data;
+	int retval;
+
+	mutex_lock(&inode->i_mutex);
+	retval = fasync_helper(fd, filp, on, &event->fasync);
+	mutex_unlock(&inode->i_mutex);
+
+	if (retval < 0)
+		return retval;
+
+	return 0;
+}
+
+static const struct file_operations perf_fops = {
+	.release		= perf_release,
+	.read			= perf_read,
+	.poll			= perf_poll,
+	.unlocked_ioctl		= perf_ioctl,
+	.compat_ioctl		= perf_ioctl,
+	.mmap			= perf_mmap,
+	.fasync			= perf_fasync,
+};
+
+/*
+ * Perf event wakeup
+ *
+ * If there's data, ensure we set the poll() state and publish everything
+ * to user-space before waking everybody up.
+ */
+
+void perf_event_wakeup(struct perf_event *event)
+{
+	wake_up_all(&event->waitq);
+
+	if (event->pending_kill) {
+		kill_fasync(&event->fasync, SIGIO, event->pending_kill);
+		event->pending_kill = 0;
+	}
+}
+
+/*
+ * Pending wakeups
+ *
+ * Handle the case where we need to wakeup up from NMI (or rq->lock) context.
+ *
+ * The NMI bit means we cannot possibly take locks. Therefore, maintain a
+ * single linked list and use cmpxchg() to add entries lockless.
+ */
+
+static void perf_pending_event(struct perf_pending_entry *entry)
+{
+	struct perf_event *event = container_of(entry,
+			struct perf_event, pending);
+
+	if (event->pending_disable) {
+		event->pending_disable = 0;
+		__perf_event_disable(event);
+	}
+
+	if (event->pending_wakeup) {
+		event->pending_wakeup = 0;
+		perf_event_wakeup(event);
+	}
+}
+
+#define PENDING_TAIL ((struct perf_pending_entry *)-1UL)
+
+static DEFINE_PER_CPU(struct perf_pending_entry *, perf_pending_head) = {
+	PENDING_TAIL,
+};
+
+static void perf_pending_queue(struct perf_pending_entry *entry,
+			       void (*func)(struct perf_pending_entry *))
+{
+	struct perf_pending_entry **head;
+
+	if (cmpxchg(&entry->next, NULL, PENDING_TAIL) != NULL)
+		return;
+
+	entry->func = func;
+
+	head = &get_cpu_var(perf_pending_head);
+
+	do {
+		entry->next = *head;
+	} while (cmpxchg(head, entry->next, entry) != entry->next);
+
+	set_perf_event_pending();
+
+	put_cpu_var(perf_pending_head);
+}
+
+static int __perf_pending_run(void)
+{
+	struct perf_pending_entry *list;
+	int nr = 0;
+
+	list = xchg(&__get_cpu_var(perf_pending_head), PENDING_TAIL);
+	while (list != PENDING_TAIL) {
+		void (*func)(struct perf_pending_entry *);
+		struct perf_pending_entry *entry = list;
+
+		list = list->next;
+
+		func = entry->func;
+		entry->next = NULL;
+		/*
+		 * Ensure we observe the unqueue before we issue the wakeup,
+		 * so that we won't be waiting forever.
+		 * -- see perf_not_pending().
+		 */
+		smp_wmb();
+
+		func(entry);
+		nr++;
+	}
+
+	return nr;
+}
+
+static inline int perf_not_pending(struct perf_event *event)
+{
+	/*
+	 * If we flush on whatever cpu we run, there is a chance we don't
+	 * need to wait.
+	 */
+	get_cpu();
+	__perf_pending_run();
+	put_cpu();
+
+	/*
+	 * Ensure we see the proper queue state before going to sleep
+	 * so that we do not miss the wakeup. -- see perf_pending_handle()
+	 */
+	smp_rmb();
+	return event->pending.next == NULL;
+}
+
+static void perf_pending_sync(struct perf_event *event)
+{
+	wait_event(event->waitq, perf_not_pending(event));
+}
+
+void perf_event_do_pending(void)
+{
+	__perf_pending_run();
+}
+
+/*
+ * Callchain support -- arch specific
+ */
+
+__weak struct perf_callchain_entry *perf_callchain(struct pt_regs *regs)
+{
+	return NULL;
+}
+
+/*
+ * Output
+ */
+static bool perf_output_space(struct perf_mmap_data *data, unsigned long tail,
+			      unsigned long offset, unsigned long head)
+{
+	unsigned long mask;
+
+	if (!data->writable)
+		return true;
+
+	mask = perf_data_size(data) - 1;
+
+	offset = (offset - tail) & mask;
+	head   = (head   - tail) & mask;
+
+	if ((int)(head - offset) < 0)
+		return false;
+
+	return true;
+}
+
+static void perf_output_wakeup(struct perf_output_handle *handle)
+{
+	atomic_set(&handle->data->poll, POLL_IN);
+
+	if (handle->nmi) {
+		handle->event->pending_wakeup = 1;
+		perf_pending_queue(&handle->event->pending,
+				   perf_pending_event);
+	} else
+		perf_event_wakeup(handle->event);
+}
+
+/*
+ * Curious locking construct.
+ *
+ * We need to ensure a later event_id doesn't publish a head when a former
+ * event_id isn't done writing. However since we need to deal with NMIs we
+ * cannot fully serialize things.
+ *
+ * What we do is serialize between CPUs so we only have to deal with NMI
+ * nesting on a single CPU.
+ *
+ * We only publish the head (and generate a wakeup) when the outer-most
+ * event_id completes.
+ */
+static void perf_output_lock(struct perf_output_handle *handle)
+{
+	struct perf_mmap_data *data = handle->data;
+	int cpu;
+
+	handle->locked = 0;
+
+	local_irq_save(handle->flags);
+	cpu = smp_processor_id();
+
+	if (in_nmi() && atomic_read(&data->lock) == cpu)
+		return;
+
+	while (atomic_cmpxchg(&data->lock, -1, cpu) != -1)
+		cpu_relax();
+
+	handle->locked = 1;
+}
+
+static void perf_output_unlock(struct perf_output_handle *handle)
+{
+	struct perf_mmap_data *data = handle->data;
+	unsigned long head;
+	int cpu;
+
+	data->done_head = data->head;
+
+	if (!handle->locked)
+		goto out;
+
+again:
+	/*
+	 * The xchg implies a full barrier that ensures all writes are done
+	 * before we publish the new head, matched by a rmb() in userspace when
+	 * reading this position.
+	 */
+	while ((head = atomic_long_xchg(&data->done_head, 0)))
+		data->user_page->data_head = head;
+
+	/*
+	 * NMI can happen here, which means we can miss a done_head update.
+	 */
+
+	cpu = atomic_xchg(&data->lock, -1);
+	WARN_ON_ONCE(cpu != smp_processor_id());
+
+	/*
+	 * Therefore we have to validate we did not indeed do so.
+	 */
+	if (unlikely(atomic_long_read(&data->done_head))) {
+		/*
+		 * Since we had it locked, we can lock it again.
+		 */
+		while (atomic_cmpxchg(&data->lock, -1, cpu) != -1)
+			cpu_relax();
+
+		goto again;
+	}
+
+	if (atomic_xchg(&data->wakeup, 0))
+		perf_output_wakeup(handle);
+out:
+	local_irq_restore(handle->flags);
+}
+
+void perf_output_copy(struct perf_output_handle *handle,
+		      const void *buf, unsigned int len)
+{
+	unsigned int pages_mask;
+	unsigned long offset;
+	unsigned int size;
+	void **pages;
+
+	offset		= handle->offset;
+	pages_mask	= handle->data->nr_pages - 1;
+	pages		= handle->data->data_pages;
+
+	do {
+		unsigned long page_offset;
+		unsigned long page_size;
+		int nr;
+
+		nr	    = (offset >> PAGE_SHIFT) & pages_mask;
+		page_size   = 1UL << (handle->data->data_order + PAGE_SHIFT);
+		page_offset = offset & (page_size - 1);
+		size	    = min_t(unsigned int, page_size - page_offset, len);
+
+		memcpy(pages[nr] + page_offset, buf, size);
+
+		len	    -= size;
+		buf	    += size;
+		offset	    += size;
+	} while (len);
+
+	handle->offset = offset;
+
+	/*
+	 * Check we didn't copy past our reservation window, taking the
+	 * possible unsigned int wrap into account.
+	 */
+	WARN_ON_ONCE(((long)(handle->head - handle->offset)) < 0);
+}
+
+int perf_output_begin(struct perf_output_handle *handle,
+		      struct perf_event *event, unsigned int size,
+		      int nmi, int sample)
+{
+	struct perf_event *output_event;
+	struct perf_mmap_data *data;
+	unsigned long tail, offset, head;
+	int have_lost;
+	struct {
+		struct perf_event_header header;
+		u64			 id;
+		u64			 lost;
+	} lost_event;
+
+	rcu_read_lock();
+	/*
+	 * For inherited events we send all the output towards the parent.
+	 */
+	if (event->parent)
+		event = event->parent;
+
+	output_event = rcu_dereference(event->output);
+	if (output_event)
+		event = output_event;
+
+	data = rcu_dereference(event->data);
+	if (!data)
+		goto out;
+
+	handle->data	= data;
+	handle->event	= event;
+	handle->nmi	= nmi;
+	handle->sample	= sample;
+
+	if (!data->nr_pages)
+		goto fail;
+
+	have_lost = atomic_read(&data->lost);
+	if (have_lost)
+		size += sizeof(lost_event);
+
+	perf_output_lock(handle);
+
+	do {
+		/*
+		 * Userspace could choose to issue a mb() before updating the
+		 * tail pointer. So that all reads will be completed before the
+		 * write is issued.
+		 */
+		tail = ACCESS_ONCE(data->user_page->data_tail);
+		smp_rmb();
+		offset = head = atomic_long_read(&data->head);
+		head += size;
+		if (unlikely(!perf_output_space(data, tail, offset, head)))
+			goto fail;
+	} while (atomic_long_cmpxchg(&data->head, offset, head) != offset);
+
+	handle->offset	= offset;
+	handle->head	= head;
+
+	if (head - tail > data->watermark)
+		atomic_set(&data->wakeup, 1);
+
+	if (have_lost) {
+		lost_event.header.type = PERF_RECORD_LOST;
+		lost_event.header.misc = 0;
+		lost_event.header.size = sizeof(lost_event);
+		lost_event.id          = event->id;
+		lost_event.lost        = atomic_xchg(&data->lost, 0);
+
+		perf_output_put(handle, lost_event);
+	}
+
+	return 0;
+
+fail:
+	atomic_inc(&data->lost);
+	perf_output_unlock(handle);
+out:
+	rcu_read_unlock();
+
+	return -ENOSPC;
+}
+
+void perf_output_end(struct perf_output_handle *handle)
+{
+	struct perf_event *event = handle->event;
+	struct perf_mmap_data *data = handle->data;
+
+	int wakeup_events = event->attr.wakeup_events;
+
+	if (handle->sample && wakeup_events) {
+		int events = atomic_inc_return(&data->events);
+		if (events >= wakeup_events) {
+			atomic_sub(wakeup_events, &data->events);
+			atomic_set(&data->wakeup, 1);
+		}
+	}
+
+	perf_output_unlock(handle);
+	rcu_read_unlock();
+}
+
+static u32 perf_event_pid(struct perf_event *event, struct task_struct *p)
+{
+	/*
+	 * only top level events have the pid namespace they were created in
+	 */
+	if (event->parent)
+		event = event->parent;
+
+	return task_tgid_nr_ns(p, event->ns);
+}
+
+static u32 perf_event_tid(struct perf_event *event, struct task_struct *p)
+{
+	/*
+	 * only top level events have the pid namespace they were created in
+	 */
+	if (event->parent)
+		event = event->parent;
+
+	return task_pid_nr_ns(p, event->ns);
+}
+
+static void perf_output_read_one(struct perf_output_handle *handle,
+				 struct perf_event *event)
+{
+	u64 read_format = event->attr.read_format;
+	u64 values[4];
+	int n = 0;
+
+	values[n++] = atomic64_read(&event->count);
+	if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
+		values[n++] = event->total_time_enabled +
+			atomic64_read(&event->child_total_time_enabled);
+	}
+	if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
+		values[n++] = event->total_time_running +
+			atomic64_read(&event->child_total_time_running);
+	}
+	if (read_format & PERF_FORMAT_ID)
+		values[n++] = primary_event_id(event);
+
+	perf_output_copy(handle, values, n * sizeof(u64));
+}
+
+/*
+ * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
+ */
+static void perf_output_read_group(struct perf_output_handle *handle,
+			    struct perf_event *event)
+{
+	struct perf_event *leader = event->group_leader, *sub;
+	u64 read_format = event->attr.read_format;
+	u64 values[5];
+	int n = 0;
+
+	values[n++] = 1 + leader->nr_siblings;
+
+	if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
+		values[n++] = leader->total_time_enabled;
+
+	if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
+		values[n++] = leader->total_time_running;
+
+	if (leader != event)
+		leader->pmu->read(leader);
+
+	values[n++] = atomic64_read(&leader->count);
+	if (read_format & PERF_FORMAT_ID)
+		values[n++] = primary_event_id(leader);
+
+	perf_output_copy(handle, values, n * sizeof(u64));
+
+	list_for_each_entry(sub, &leader->sibling_list, group_entry) {
+		n = 0;
+
+		if (sub != event)
+			sub->pmu->read(sub);
+
+		values[n++] = atomic64_read(&sub->count);
+		if (read_format & PERF_FORMAT_ID)
+			values[n++] = primary_event_id(sub);
+
+		perf_output_copy(handle, values, n * sizeof(u64));
+	}
+}
+
+static void perf_output_read(struct perf_output_handle *handle,
+			     struct perf_event *event)
+{
+	if (event->attr.read_format & PERF_FORMAT_GROUP)
+		perf_output_read_group(handle, event);
+	else
+		perf_output_read_one(handle, event);
+}
+
+void perf_output_sample(struct perf_output_handle *handle,
+			struct perf_event_header *header,
+			struct perf_sample_data *data,
+			struct perf_event *event)
+{
+	u64 sample_type = data->type;
+
+	perf_output_put(handle, *header);
+
+	if (sample_type & PERF_SAMPLE_IP)
+		perf_output_put(handle, data->ip);
+
+	if (sample_type & PERF_SAMPLE_TID)
+		perf_output_put(handle, data->tid_entry);
+
+	if (sample_type & PERF_SAMPLE_TIME)
+		perf_output_put(handle, data->time);
+
+	if (sample_type & PERF_SAMPLE_ADDR)
+		perf_output_put(handle, data->addr);
+
+	if (sample_type & PERF_SAMPLE_ID)
+		perf_output_put(handle, data->id);
+
+	if (sample_type & PERF_SAMPLE_STREAM_ID)
+		perf_output_put(handle, data->stream_id);
+
+	if (sample_type & PERF_SAMPLE_CPU)
+		perf_output_put(handle, data->cpu_entry);
+
+	if (sample_type & PERF_SAMPLE_PERIOD)
+		perf_output_put(handle, data->period);
+
+	if (sample_type & PERF_SAMPLE_READ)
+		perf_output_read(handle, event);
+
+	if (sample_type & PERF_SAMPLE_CALLCHAIN) {
+		if (data->callchain) {
+			int size = 1;
+
+			if (data->callchain)
+				size += data->callchain->nr;
+
+			size *= sizeof(u64);
+
+			perf_output_copy(handle, data->callchain, size);
+		} else {
+			u64 nr = 0;
+			perf_output_put(handle, nr);
+		}
+	}
+
+	if (sample_type & PERF_SAMPLE_RAW) {
+		if (data->raw) {
+			perf_output_put(handle, data->raw->size);
+			perf_output_copy(handle, data->raw->data,
+					 data->raw->size);
+		} else {
+			struct {
+				u32	size;
+				u32	data;
+			} raw = {
+				.size = sizeof(u32),
+				.data = 0,
+			};
+			perf_output_put(handle, raw);
+		}
+	}
+}
+
+void perf_prepare_sample(struct perf_event_header *header,
+			 struct perf_sample_data *data,
+			 struct perf_event *event,
+			 struct pt_regs *regs)
+{
+	u64 sample_type = event->attr.sample_type;
+
+	data->type = sample_type;
+
+	header->type = PERF_RECORD_SAMPLE;
+	header->size = sizeof(*header);
+
+	header->misc = 0;
+	header->misc |= perf_misc_flags(regs);
+
+	if (sample_type & PERF_SAMPLE_IP) {
+		data->ip = perf_instruction_pointer(regs);
+
+		header->size += sizeof(data->ip);
+	}
+
+	if (sample_type & PERF_SAMPLE_TID) {
+		/* namespace issues */
+		data->tid_entry.pid = perf_event_pid(event, current);
+		data->tid_entry.tid = perf_event_tid(event, current);
+
+		header->size += sizeof(data->tid_entry);
+	}
+
+	if (sample_type & PERF_SAMPLE_TIME) {
+		data->time = perf_clock();
+
+		header->size += sizeof(data->time);
+	}
+
+	if (sample_type & PERF_SAMPLE_ADDR)
+		header->size += sizeof(data->addr);
+
+	if (sample_type & PERF_SAMPLE_ID) {
+		data->id = primary_event_id(event);
+
+		header->size += sizeof(data->id);
+	}
+
+	if (sample_type & PERF_SAMPLE_STREAM_ID) {
+		data->stream_id = event->id;
+
+		header->size += sizeof(data->stream_id);
+	}
+
+	if (sample_type & PERF_SAMPLE_CPU) {
+		data->cpu_entry.cpu		= raw_smp_processor_id();
+		data->cpu_entry.reserved	= 0;
+
+		header->size += sizeof(data->cpu_entry);
+	}
+
+	if (sample_type & PERF_SAMPLE_PERIOD)
+		header->size += sizeof(data->period);
+
+	if (sample_type & PERF_SAMPLE_READ)
+		header->size += perf_event_read_size(event);
+
+	if (sample_type & PERF_SAMPLE_CALLCHAIN) {
+		int size = 1;
+
+		data->callchain = perf_callchain(regs);
+
+		if (data->callchain)
+			size += data->callchain->nr;
+
+		header->size += size * sizeof(u64);
+	}
+
+	if (sample_type & PERF_SAMPLE_RAW) {
+		int size = sizeof(u32);
+
+		if (data->raw)
+			size += data->raw->size;
+		else
+			size += sizeof(u32);
+
+		WARN_ON_ONCE(size & (sizeof(u64)-1));
+		header->size += size;
+	}
+}
+
+static void perf_event_output(struct perf_event *event, int nmi,
+				struct perf_sample_data *data,
+				struct pt_regs *regs)
+{
+	struct perf_output_handle handle;
+	struct perf_event_header header;
+
+	perf_prepare_sample(&header, data, event, regs);
+
+	if (perf_output_begin(&handle, event, header.size, nmi, 1))
+		return;
+
+	perf_output_sample(&handle, &header, data, event);
+
+	perf_output_end(&handle);
+}
+
+/*
+ * read event_id
+ */
+
+struct perf_read_event {
+	struct perf_event_header	header;
+
+	u32				pid;
+	u32				tid;
+};
+
+static void
+perf_event_read_event(struct perf_event *event,
+			struct task_struct *task)
+{
+	struct perf_output_handle handle;
+	struct perf_read_event read_event = {
+		.header = {
+			.type = PERF_RECORD_READ,
+			.misc = 0,
+			.size = sizeof(read_event) + perf_event_read_size(event),
+		},
+		.pid = perf_event_pid(event, task),
+		.tid = perf_event_tid(event, task),
+	};
+	int ret;
+
+	ret = perf_output_begin(&handle, event, read_event.header.size, 0, 0);
+	if (ret)
+		return;
+
+	perf_output_put(&handle, read_event);
+	perf_output_read(&handle, event);
+
+	perf_output_end(&handle);
+}
+
+/*
+ * task tracking -- fork/exit
+ *
+ * enabled by: attr.comm | attr.mmap | attr.task
+ */
+
+struct perf_task_event {
+	struct task_struct		*task;
+	struct perf_event_context	*task_ctx;
+
+	struct {
+		struct perf_event_header	header;
+
+		u32				pid;
+		u32				ppid;
+		u32				tid;
+		u32				ptid;
+		u64				time;
+	} event_id;
+};
+
+static void perf_event_task_output(struct perf_event *event,
+				     struct perf_task_event *task_event)
+{
+	struct perf_output_handle handle;
+	int size;
+	struct task_struct *task = task_event->task;
+	int ret;
+
+	size  = task_event->event_id.header.size;
+	ret = perf_output_begin(&handle, event, size, 0, 0);
+
+	if (ret)
+		return;
+
+	task_event->event_id.pid = perf_event_pid(event, task);
+	task_event->event_id.ppid = perf_event_pid(event, current);
+
+	task_event->event_id.tid = perf_event_tid(event, task);
+	task_event->event_id.ptid = perf_event_tid(event, current);
+
+	task_event->event_id.time = perf_clock();
+
+	perf_output_put(&handle, task_event->event_id);
+
+	perf_output_end(&handle);
+}
+
+static int perf_event_task_match(struct perf_event *event)
+{
+	if (event->attr.comm || event->attr.mmap || event->attr.task)
+		return 1;
+
+	return 0;
+}
+
+static void perf_event_task_ctx(struct perf_event_context *ctx,
+				  struct perf_task_event *task_event)
+{
+	struct perf_event *event;
+
+	if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list))
+		return;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
+		if (perf_event_task_match(event))
+			perf_event_task_output(event, task_event);
+	}
+	rcu_read_unlock();
+}
+
+static void perf_event_task_event(struct perf_task_event *task_event)
+{
+	struct perf_cpu_context *cpuctx;
+	struct perf_event_context *ctx = task_event->task_ctx;
+
+	cpuctx = &get_cpu_var(perf_cpu_context);
+	perf_event_task_ctx(&cpuctx->ctx, task_event);
+	put_cpu_var(perf_cpu_context);
+
+	rcu_read_lock();
+	if (!ctx)
+		ctx = rcu_dereference(task_event->task->perf_event_ctxp);
+	if (ctx)
+		perf_event_task_ctx(ctx, task_event);
+	rcu_read_unlock();
+}
+
+static void perf_event_task(struct task_struct *task,
+			      struct perf_event_context *task_ctx,
+			      int new)
+{
+	struct perf_task_event task_event;
+
+	if (!atomic_read(&nr_comm_events) &&
+	    !atomic_read(&nr_mmap_events) &&
+	    !atomic_read(&nr_task_events))
+		return;
+
+	task_event = (struct perf_task_event){
+		.task	  = task,
+		.task_ctx = task_ctx,
+		.event_id    = {
+			.header = {
+				.type = new ? PERF_RECORD_FORK : PERF_RECORD_EXIT,
+				.misc = 0,
+				.size = sizeof(task_event.event_id),
+			},
+			/* .pid  */
+			/* .ppid */
+			/* .tid  */
+			/* .ptid */
+		},
+	};
+
+	perf_event_task_event(&task_event);
+}
+
+void perf_event_fork(struct task_struct *task)
+{
+	perf_event_task(task, NULL, 1);
+}
+
+/*
+ * comm tracking
+ */
+
+struct perf_comm_event {
+	struct task_struct	*task;
+	char			*comm;
+	int			comm_size;
+
+	struct {
+		struct perf_event_header	header;
+
+		u32				pid;
+		u32				tid;
+	} event_id;
+};
+
+static void perf_event_comm_output(struct perf_event *event,
+				     struct perf_comm_event *comm_event)
+{
+	struct perf_output_handle handle;
+	int size = comm_event->event_id.header.size;
+	int ret = perf_output_begin(&handle, event, size, 0, 0);
+
+	if (ret)
+		return;
+
+	comm_event->event_id.pid = perf_event_pid(event, comm_event->task);
+	comm_event->event_id.tid = perf_event_tid(event, comm_event->task);
+
+	perf_output_put(&handle, comm_event->event_id);
+	perf_output_copy(&handle, comm_event->comm,
+				   comm_event->comm_size);
+	perf_output_end(&handle);
+}
+
+static int perf_event_comm_match(struct perf_event *event)
+{
+	if (event->attr.comm)
+		return 1;
+
+	return 0;
+}
+
+static void perf_event_comm_ctx(struct perf_event_context *ctx,
+				  struct perf_comm_event *comm_event)
+{
+	struct perf_event *event;
+
+	if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list))
+		return;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
+		if (perf_event_comm_match(event))
+			perf_event_comm_output(event, comm_event);
+	}
+	rcu_read_unlock();
+}
+
+static void perf_event_comm_event(struct perf_comm_event *comm_event)
+{
+	struct perf_cpu_context *cpuctx;
+	struct perf_event_context *ctx;
+	unsigned int size;
+	char comm[TASK_COMM_LEN];
+
+	memset(comm, 0, sizeof(comm));
+	strncpy(comm, comm_event->task->comm, sizeof(comm));
+	size = ALIGN(strlen(comm)+1, sizeof(u64));
+
+	comm_event->comm = comm;
+	comm_event->comm_size = size;
+
+	comm_event->event_id.header.size = sizeof(comm_event->event_id) + size;
+
+	cpuctx = &get_cpu_var(perf_cpu_context);
+	perf_event_comm_ctx(&cpuctx->ctx, comm_event);
+	put_cpu_var(perf_cpu_context);
+
+	rcu_read_lock();
+	/*
+	 * doesn't really matter which of the child contexts the
+	 * events ends up in.
+	 */
+	ctx = rcu_dereference(current->perf_event_ctxp);
+	if (ctx)
+		perf_event_comm_ctx(ctx, comm_event);
+	rcu_read_unlock();
+}
+
+void perf_event_comm(struct task_struct *task)
+{
+	struct perf_comm_event comm_event;
+
+	if (task->perf_event_ctxp)
+		perf_event_enable_on_exec(task);
+
+	if (!atomic_read(&nr_comm_events))
+		return;
+
+	comm_event = (struct perf_comm_event){
+		.task	= task,
+		/* .comm      */
+		/* .comm_size */
+		.event_id  = {
+			.header = {
+				.type = PERF_RECORD_COMM,
+				.misc = 0,
+				/* .size */
+			},
+			/* .pid */
+			/* .tid */
+		},
+	};
+
+	perf_event_comm_event(&comm_event);
+}
+
+/*
+ * mmap tracking
+ */
+
+struct perf_mmap_event {
+	struct vm_area_struct	*vma;
+
+	const char		*file_name;
+	int			file_size;
+
+	struct {
+		struct perf_event_header	header;
+
+		u32				pid;
+		u32				tid;
+		u64				start;
+		u64				len;
+		u64				pgoff;
+	} event_id;
+};
+
+static void perf_event_mmap_output(struct perf_event *event,
+				     struct perf_mmap_event *mmap_event)
+{
+	struct perf_output_handle handle;
+	int size = mmap_event->event_id.header.size;
+	int ret = perf_output_begin(&handle, event, size, 0, 0);
+
+	if (ret)
+		return;
+
+	mmap_event->event_id.pid = perf_event_pid(event, current);
+	mmap_event->event_id.tid = perf_event_tid(event, current);
+
+	perf_output_put(&handle, mmap_event->event_id);
+	perf_output_copy(&handle, mmap_event->file_name,
+				   mmap_event->file_size);
+	perf_output_end(&handle);
+}
+
+static int perf_event_mmap_match(struct perf_event *event,
+				   struct perf_mmap_event *mmap_event)
+{
+	if (event->attr.mmap)
+		return 1;
+
+	return 0;
+}
+
+static void perf_event_mmap_ctx(struct perf_event_context *ctx,
+				  struct perf_mmap_event *mmap_event)
+{
+	struct perf_event *event;
+
+	if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list))
+		return;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
+		if (perf_event_mmap_match(event, mmap_event))
+			perf_event_mmap_output(event, mmap_event);
+	}
+	rcu_read_unlock();
+}
+
+static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
+{
+	struct perf_cpu_context *cpuctx;
+	struct perf_event_context *ctx;
+	struct vm_area_struct *vma = mmap_event->vma;
+	struct file *file = vma->vm_file;
+	unsigned int size;
+	char tmp[16];
+	char *buf = NULL;
+	const char *name;
+
+	memset(tmp, 0, sizeof(tmp));
+
+	if (file) {
+		/*
+		 * d_path works from the end of the buffer backwards, so we
+		 * need to add enough zero bytes after the string to handle
+		 * the 64bit alignment we do later.
+		 */
+		buf = kzalloc(PATH_MAX + sizeof(u64), GFP_KERNEL);
+		if (!buf) {
+			name = strncpy(tmp, "//enomem", sizeof(tmp));
+			goto got_name;
+		}
+		name = d_path(&file->f_path, buf, PATH_MAX);
+		if (IS_ERR(name)) {
+			name = strncpy(tmp, "//toolong", sizeof(tmp));
+			goto got_name;
+		}
+	} else {
+		if (arch_vma_name(mmap_event->vma)) {
+			name = strncpy(tmp, arch_vma_name(mmap_event->vma),
+				       sizeof(tmp));
+			goto got_name;
+		}
+
+		if (!vma->vm_mm) {
+			name = strncpy(tmp, "[vdso]", sizeof(tmp));
+			goto got_name;
+		}
+
+		name = strncpy(tmp, "//anon", sizeof(tmp));
+		goto got_name;
+	}
+
+got_name:
+	size = ALIGN(strlen(name)+1, sizeof(u64));
+
+	mmap_event->file_name = name;
+	mmap_event->file_size = size;
+
+	mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size;
+
+	cpuctx = &get_cpu_var(perf_cpu_context);
+	perf_event_mmap_ctx(&cpuctx->ctx, mmap_event);
+	put_cpu_var(perf_cpu_context);
+
+	rcu_read_lock();
+	/*
+	 * doesn't really matter which of the child contexts the
+	 * events ends up in.
+	 */
+	ctx = rcu_dereference(current->perf_event_ctxp);
+	if (ctx)
+		perf_event_mmap_ctx(ctx, mmap_event);
+	rcu_read_unlock();
+
+	kfree(buf);
+}
+
+void __perf_event_mmap(struct vm_area_struct *vma)
+{
+	struct perf_mmap_event mmap_event;
+
+	if (!atomic_read(&nr_mmap_events))
+		return;
+
+	mmap_event = (struct perf_mmap_event){
+		.vma	= vma,
+		/* .file_name */
+		/* .file_size */
+		.event_id  = {
+			.header = {
+				.type = PERF_RECORD_MMAP,
+				.misc = 0,
+				/* .size */
+			},
+			/* .pid */
+			/* .tid */
+			.start  = vma->vm_start,
+			.len    = vma->vm_end - vma->vm_start,
+			.pgoff  = vma->vm_pgoff,
+		},
+	};
+
+	perf_event_mmap_event(&mmap_event);
+}
+
+/*
+ * IRQ throttle logging
+ */
+
+static void perf_log_throttle(struct perf_event *event, int enable)
+{
+	struct perf_output_handle handle;
+	int ret;
+
+	struct {
+		struct perf_event_header	header;
+		u64				time;
+		u64				id;
+		u64				stream_id;
+	} throttle_event = {
+		.header = {
+			.type = PERF_RECORD_THROTTLE,
+			.misc = 0,
+			.size = sizeof(throttle_event),
+		},
+		.time		= perf_clock(),
+		.id		= primary_event_id(event),
+		.stream_id	= event->id,
+	};
+
+	if (enable)
+		throttle_event.header.type = PERF_RECORD_UNTHROTTLE;
+
+	ret = perf_output_begin(&handle, event, sizeof(throttle_event), 1, 0);
+	if (ret)
+		return;
+
+	perf_output_put(&handle, throttle_event);
+	perf_output_end(&handle);
+}
+
+/*
+ * Generic event overflow handling, sampling.
+ */
+
+static int __perf_event_overflow(struct perf_event *event, int nmi,
+				   int throttle, struct perf_sample_data *data,
+				   struct pt_regs *regs)
+{
+	int events = atomic_read(&event->event_limit);
+	struct hw_perf_event *hwc = &event->hw;
+	int ret = 0;
+
+	throttle = (throttle && event->pmu->unthrottle != NULL);
+
+	if (!throttle) {
+		hwc->interrupts++;
+	} else {
+		if (hwc->interrupts != MAX_INTERRUPTS) {
+			hwc->interrupts++;
+			if (HZ * hwc->interrupts >
+					(u64)sysctl_perf_event_sample_rate) {
+				hwc->interrupts = MAX_INTERRUPTS;
+				perf_log_throttle(event, 0);
+				ret = 1;
+			}
+		} else {
+			/*
+			 * Keep re-disabling events even though on the previous
+			 * pass we disabled it - just in case we raced with a
+			 * sched-in and the event got enabled again:
+			 */
+			ret = 1;
+		}
+	}
+
+	if (event->attr.freq) {
+		u64 now = perf_clock();
+		s64 delta = now - hwc->freq_stamp;
+
+		hwc->freq_stamp = now;
+
+		if (delta > 0 && delta < TICK_NSEC)
+			perf_adjust_period(event, NSEC_PER_SEC / (int)delta);
+	}
+
+	/*
+	 * XXX event_limit might not quite work as expected on inherited
+	 * events
+	 */
+
+	event->pending_kill = POLL_IN;
+	if (events && atomic_dec_and_test(&event->event_limit)) {
+		ret = 1;
+		event->pending_kill = POLL_HUP;
+		if (nmi) {
+			event->pending_disable = 1;
+			perf_pending_queue(&event->pending,
+					   perf_pending_event);
+		} else
+			perf_event_disable(event);
+	}
+
+	perf_event_output(event, nmi, data, regs);
+	return ret;
+}
+
+int perf_event_overflow(struct perf_event *event, int nmi,
+			  struct perf_sample_data *data,
+			  struct pt_regs *regs)
+{
+	return __perf_event_overflow(event, nmi, 1, data, regs);
+}
+
+/*
+ * Generic software event infrastructure
+ */
+
+/*
+ * We directly increment event->count and keep a second value in
+ * event->hw.period_left to count intervals. This period event
+ * is kept in the range [-sample_period, 0] so that we can use the
+ * sign as trigger.
+ */
+
+static u64 perf_swevent_set_period(struct perf_event *event)
+{
+	struct hw_perf_event *hwc = &event->hw;
+	u64 period = hwc->last_period;
+	u64 nr, offset;
+	s64 old, val;
+
+	hwc->last_period = hwc->sample_period;
+
+again:
+	old = val = atomic64_read(&hwc->period_left);
+	if (val < 0)
+		return 0;
+
+	nr = div64_u64(period + val, period);
+	offset = nr * period;
+	val -= offset;
+	if (atomic64_cmpxchg(&hwc->period_left, old, val) != old)
+		goto again;
+
+	return nr;
+}
+
+static void perf_swevent_overflow(struct perf_event *event,
+				    int nmi, struct perf_sample_data *data,
+				    struct pt_regs *regs)
+{
+	struct hw_perf_event *hwc = &event->hw;
+	int throttle = 0;
+	u64 overflow;
+
+	data->period = event->hw.last_period;
+	overflow = perf_swevent_set_period(event);
+
+	if (hwc->interrupts == MAX_INTERRUPTS)
+		return;
+
+	for (; overflow; overflow--) {
+		if (__perf_event_overflow(event, nmi, throttle,
+					    data, regs)) {
+			/*
+			 * We inhibit the overflow from happening when
+			 * hwc->interrupts == MAX_INTERRUPTS.
+			 */
+			break;
+		}
+		throttle = 1;
+	}
+}
+
+static void perf_swevent_unthrottle(struct perf_event *event)
+{
+	/*
+	 * Nothing to do, we already reset hwc->interrupts.
+	 */
+}
+
+static void perf_swevent_add(struct perf_event *event, u64 nr,
+			       int nmi, struct perf_sample_data *data,
+			       struct pt_regs *regs)
+{
+	struct hw_perf_event *hwc = &event->hw;
+
+	atomic64_add(nr, &event->count);
+
+	if (!hwc->sample_period)
+		return;
+
+	if (!regs)
+		return;
+
+	if (!atomic64_add_negative(nr, &hwc->period_left))
+		perf_swevent_overflow(event, nmi, data, regs);
+}
+
+static int perf_swevent_is_counting(struct perf_event *event)
+{
+	/*
+	 * The event is active, we're good!
+	 */
+	if (event->state == PERF_EVENT_STATE_ACTIVE)
+		return 1;
+
+	/*
+	 * The event is off/error, not counting.
+	 */
+	if (event->state != PERF_EVENT_STATE_INACTIVE)
+		return 0;
+
+	/*
+	 * The event is inactive, if the context is active
+	 * we're part of a group that didn't make it on the 'pmu',
+	 * not counting.
+	 */
+	if (event->ctx->is_active)
+		return 0;
+
+	/*
+	 * We're inactive and the context is too, this means the
+	 * task is scheduled out, we're counting events that happen
+	 * to us, like migration events.
+	 */
+	return 1;
+}
+
+static int perf_swevent_match(struct perf_event *event,
+				enum perf_type_id type,
+				u32 event_id, struct pt_regs *regs)
+{
+	if (!perf_swevent_is_counting(event))
+		return 0;
+
+	if (event->attr.type != type)
+		return 0;
+	if (event->attr.config != event_id)
+		return 0;
+
+	if (regs) {
+		if (event->attr.exclude_user && user_mode(regs))
+			return 0;
+
+		if (event->attr.exclude_kernel && !user_mode(regs))
+			return 0;
+	}
+
+	return 1;
+}
+
+static void perf_swevent_ctx_event(struct perf_event_context *ctx,
+				     enum perf_type_id type,
+				     u32 event_id, u64 nr, int nmi,
+				     struct perf_sample_data *data,
+				     struct pt_regs *regs)
+{
+	struct perf_event *event;
+
+	if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list))
+		return;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
+		if (perf_swevent_match(event, type, event_id, regs))
+			perf_swevent_add(event, nr, nmi, data, regs);
+	}
+	rcu_read_unlock();
+}
+
+static int *perf_swevent_recursion_context(struct perf_cpu_context *cpuctx)
+{
+	if (in_nmi())
+		return &cpuctx->recursion[3];
+
+	if (in_irq())
+		return &cpuctx->recursion[2];
+
+	if (in_softirq())
+		return &cpuctx->recursion[1];
+
+	return &cpuctx->recursion[0];
+}
+
+static void do_perf_sw_event(enum perf_type_id type, u32 event_id,
+				    u64 nr, int nmi,
+				    struct perf_sample_data *data,
+				    struct pt_regs *regs)
+{
+	struct perf_cpu_context *cpuctx = &get_cpu_var(perf_cpu_context);
+	int *recursion = perf_swevent_recursion_context(cpuctx);
+	struct perf_event_context *ctx;
+
+	if (*recursion)
+		goto out;
+
+	(*recursion)++;
+	barrier();
+
+	perf_swevent_ctx_event(&cpuctx->ctx, type, event_id,
+				 nr, nmi, data, regs);
+	rcu_read_lock();
+	/*
+	 * doesn't really matter which of the child contexts the
+	 * events ends up in.
+	 */
+	ctx = rcu_dereference(current->perf_event_ctxp);
+	if (ctx)
+		perf_swevent_ctx_event(ctx, type, event_id, nr, nmi, data, regs);
+	rcu_read_unlock();
+
+	barrier();
+	(*recursion)--;
+
+out:
+	put_cpu_var(perf_cpu_context);
+}
+
+void __perf_sw_event(u32 event_id, u64 nr, int nmi,
+			    struct pt_regs *regs, u64 addr)
+{
+	struct perf_sample_data data = {
+		.addr = addr,
+	};
+
+	do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, nmi,
+				&data, regs);
+}
+
+static void perf_swevent_read(struct perf_event *event)
+{
+}
+
+static int perf_swevent_enable(struct perf_event *event)
+{
+	struct hw_perf_event *hwc = &event->hw;
+
+	if (hwc->sample_period) {
+		hwc->last_period = hwc->sample_period;
+		perf_swevent_set_period(event);
+	}
+	return 0;
+}
+
+static void perf_swevent_disable(struct perf_event *event)
+{
+}
+
+static const struct pmu perf_ops_generic = {
+	.enable		= perf_swevent_enable,
+	.disable	= perf_swevent_disable,
+	.read		= perf_swevent_read,
+	.unthrottle	= perf_swevent_unthrottle,
+};
+
+/*
+ * hrtimer based swevent callback
+ */
+
+static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer)
+{
+	enum hrtimer_restart ret = HRTIMER_RESTART;
+	struct perf_sample_data data;
+	struct pt_regs *regs;
+	struct perf_event *event;
+	u64 period;
+
+	event	= container_of(hrtimer, struct perf_event, hw.hrtimer);
+	event->pmu->read(event);
+
+	data.addr = 0;
+	regs = get_irq_regs();
+	/*
+	 * In case we exclude kernel IPs or are somehow not in interrupt
+	 * context, provide the next best thing, the user IP.
+	 */
+	if ((event->attr.exclude_kernel || !regs) &&
+			!event->attr.exclude_user)
+		regs = task_pt_regs(current);
+
+	if (regs) {
+		if (perf_event_overflow(event, 0, &data, regs))
+			ret = HRTIMER_NORESTART;
+	}
+
+	period = max_t(u64, 10000, event->hw.sample_period);
+	hrtimer_forward_now(hrtimer, ns_to_ktime(period));
+
+	return ret;
+}
+
+/*
+ * Software event: cpu wall time clock
+ */
+
+static void cpu_clock_perf_event_update(struct perf_event *event)
+{
+	int cpu = raw_smp_processor_id();
+	s64 prev;
+	u64 now;
+
+	now = cpu_clock(cpu);
+	prev = atomic64_read(&event->hw.prev_count);
+	atomic64_set(&event->hw.prev_count, now);
+	atomic64_add(now - prev, &event->count);
+}
+
+static int cpu_clock_perf_event_enable(struct perf_event *event)
+{
+	struct hw_perf_event *hwc = &event->hw;
+	int cpu = raw_smp_processor_id();
+
+	atomic64_set(&hwc->prev_count, cpu_clock(cpu));
+	hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	hwc->hrtimer.function = perf_swevent_hrtimer;
+	if (hwc->sample_period) {
+		u64 period = max_t(u64, 10000, hwc->sample_period);
+		__hrtimer_start_range_ns(&hwc->hrtimer,
+				ns_to_ktime(period), 0,
+				HRTIMER_MODE_REL, 0);
+	}
+
+	return 0;
+}
+
+static void cpu_clock_perf_event_disable(struct perf_event *event)
+{
+	if (event->hw.sample_period)
+		hrtimer_cancel(&event->hw.hrtimer);
+	cpu_clock_perf_event_update(event);
+}
+
+static void cpu_clock_perf_event_read(struct perf_event *event)
+{
+	cpu_clock_perf_event_update(event);
+}
+
+static const struct pmu perf_ops_cpu_clock = {
+	.enable		= cpu_clock_perf_event_enable,
+	.disable	= cpu_clock_perf_event_disable,
+	.read		= cpu_clock_perf_event_read,
+};
+
+/*
+ * Software event: task time clock
+ */
+
+static void task_clock_perf_event_update(struct perf_event *event, u64 now)
+{
+	u64 prev;
+	s64 delta;
+
+	prev = atomic64_xchg(&event->hw.prev_count, now);
+	delta = now - prev;
+	atomic64_add(delta, &event->count);
+}
+
+static int task_clock_perf_event_enable(struct perf_event *event)
+{
+	struct hw_perf_event *hwc = &event->hw;
+	u64 now;
+
+	now = event->ctx->time;
+
+	atomic64_set(&hwc->prev_count, now);
+	hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	hwc->hrtimer.function = perf_swevent_hrtimer;
+	if (hwc->sample_period) {
+		u64 period = max_t(u64, 10000, hwc->sample_period);
+		__hrtimer_start_range_ns(&hwc->hrtimer,
+				ns_to_ktime(period), 0,
+				HRTIMER_MODE_REL, 0);
+	}
+
+	return 0;
+}
+
+static void task_clock_perf_event_disable(struct perf_event *event)
+{
+	if (event->hw.sample_period)
+		hrtimer_cancel(&event->hw.hrtimer);
+	task_clock_perf_event_update(event, event->ctx->time);
+
+}
+
+static void task_clock_perf_event_read(struct perf_event *event)
+{
+	u64 time;
+
+	if (!in_nmi()) {
+		update_context_time(event->ctx);
+		time = event->ctx->time;
+	} else {
+		u64 now = perf_clock();
+		u64 delta = now - event->ctx->timestamp;
+		time = event->ctx->time + delta;
+	}
+
+	task_clock_perf_event_update(event, time);
+}
+
+static const struct pmu perf_ops_task_clock = {
+	.enable		= task_clock_perf_event_enable,
+	.disable	= task_clock_perf_event_disable,
+	.read		= task_clock_perf_event_read,
+};
+
+#ifdef CONFIG_EVENT_PROFILE
+void perf_tp_event(int event_id, u64 addr, u64 count, void *record,
+			  int entry_size)
+{
+	struct perf_raw_record raw = {
+		.size = entry_size,
+		.data = record,
+	};
+
+	struct perf_sample_data data = {
+		.addr = addr,
+		.raw = &raw,
+	};
+
+	struct pt_regs *regs = get_irq_regs();
+
+	if (!regs)
+		regs = task_pt_regs(current);
+
+	do_perf_sw_event(PERF_TYPE_TRACEPOINT, event_id, count, 1,
+				&data, regs);
+}
+EXPORT_SYMBOL_GPL(perf_tp_event);
+
+extern int ftrace_profile_enable(int);
+extern void ftrace_profile_disable(int);
+
+static void tp_perf_event_destroy(struct perf_event *event)
+{
+	ftrace_profile_disable(event->attr.config);
+}
+
+static const struct pmu *tp_perf_event_init(struct perf_event *event)
+{
+	/*
+	 * Raw tracepoint data is a severe data leak, only allow root to
+	 * have these.
+	 */
+	if ((event->attr.sample_type & PERF_SAMPLE_RAW) &&
+			perf_paranoid_tracepoint_raw() &&
+			!capable(CAP_SYS_ADMIN))
+		return ERR_PTR(-EPERM);
+
+	if (ftrace_profile_enable(event->attr.config))
+		return NULL;
+
+	event->destroy = tp_perf_event_destroy;
+
+	return &perf_ops_generic;
+}
+#else
+static const struct pmu *tp_perf_event_init(struct perf_event *event)
+{
+	return NULL;
+}
+#endif
+
+atomic_t perf_swevent_enabled[PERF_COUNT_SW_MAX];
+
+static void sw_perf_event_destroy(struct perf_event *event)
+{
+	u64 event_id = event->attr.config;
+
+	WARN_ON(event->parent);
+
+	atomic_dec(&perf_swevent_enabled[event_id]);
+}
+
+static const struct pmu *sw_perf_event_init(struct perf_event *event)
+{
+	const struct pmu *pmu = NULL;
+	u64 event_id = event->attr.config;
+
+	/*
+	 * Software events (currently) can't in general distinguish
+	 * between user, kernel and hypervisor events.
+	 * However, context switches and cpu migrations are considered
+	 * to be kernel events, and page faults are never hypervisor
+	 * events.
+	 */
+	switch (event_id) {
+	case PERF_COUNT_SW_CPU_CLOCK:
+		pmu = &perf_ops_cpu_clock;
+
+		break;
+	case PERF_COUNT_SW_TASK_CLOCK:
+		/*
+		 * If the user instantiates this as a per-cpu event,
+		 * use the cpu_clock event instead.
+		 */
+		if (event->ctx->task)
+			pmu = &perf_ops_task_clock;
+		else
+			pmu = &perf_ops_cpu_clock;
+
+		break;
+	case PERF_COUNT_SW_PAGE_FAULTS:
+	case PERF_COUNT_SW_PAGE_FAULTS_MIN:
+	case PERF_COUNT_SW_PAGE_FAULTS_MAJ:
+	case PERF_COUNT_SW_CONTEXT_SWITCHES:
+	case PERF_COUNT_SW_CPU_MIGRATIONS:
+		if (!event->parent) {
+			atomic_inc(&perf_swevent_enabled[event_id]);
+			event->destroy = sw_perf_event_destroy;
+		}
+		pmu = &perf_ops_generic;
+		break;
+	}
+
+	return pmu;
+}
+
+/*
+ * Allocate and initialize a event structure
+ */
+static struct perf_event *
+perf_event_alloc(struct perf_event_attr *attr,
+		   int cpu,
+		   struct perf_event_context *ctx,
+		   struct perf_event *group_leader,
+		   struct perf_event *parent_event,
+		   gfp_t gfpflags)
+{
+	const struct pmu *pmu;
+	struct perf_event *event;
+	struct hw_perf_event *hwc;
+	long err;
+
+	event = kzalloc(sizeof(*event), gfpflags);
+	if (!event)
+		return ERR_PTR(-ENOMEM);
+
+	/*
+	 * Single events are their own group leaders, with an
+	 * empty sibling list:
+	 */
+	if (!group_leader)
+		group_leader = event;
+
+	mutex_init(&event->child_mutex);
+	INIT_LIST_HEAD(&event->child_list);
+
+	INIT_LIST_HEAD(&event->group_entry);
+	INIT_LIST_HEAD(&event->event_entry);
+	INIT_LIST_HEAD(&event->sibling_list);
+	init_waitqueue_head(&event->waitq);
+
+	mutex_init(&event->mmap_mutex);
+
+	event->cpu		= cpu;
+	event->attr		= *attr;
+	event->group_leader	= group_leader;
+	event->pmu		= NULL;
+	event->ctx		= ctx;
+	event->oncpu		= -1;
+
+	event->parent		= parent_event;
+
+	event->ns		= get_pid_ns(current->nsproxy->pid_ns);
+	event->id		= atomic64_inc_return(&perf_event_id);
+
+	event->state		= PERF_EVENT_STATE_INACTIVE;
+
+	if (attr->disabled)
+		event->state = PERF_EVENT_STATE_OFF;
+
+	pmu = NULL;
+
+	hwc = &event->hw;
+	hwc->sample_period = attr->sample_period;
+	if (attr->freq && attr->sample_freq)
+		hwc->sample_period = 1;
+	hwc->last_period = hwc->sample_period;
+
+	atomic64_set(&hwc->period_left, hwc->sample_period);
+
+	/*
+	 * we currently do not support PERF_FORMAT_GROUP on inherited events
+	 */
+	if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP))
+		goto done;
+
+	switch (attr->type) {
+	case PERF_TYPE_RAW:
+	case PERF_TYPE_HARDWARE:
+	case PERF_TYPE_HW_CACHE:
+		pmu = hw_perf_event_init(event);
+		break;
+
+	case PERF_TYPE_SOFTWARE:
+		pmu = sw_perf_event_init(event);
+		break;
+
+	case PERF_TYPE_TRACEPOINT:
+		pmu = tp_perf_event_init(event);
+		break;
+
+	default:
+		break;
+	}
+done:
+	err = 0;
+	if (!pmu)
+		err = -EINVAL;
+	else if (IS_ERR(pmu))
+		err = PTR_ERR(pmu);
+
+	if (err) {
+		if (event->ns)
+			put_pid_ns(event->ns);
+		kfree(event);
+		return ERR_PTR(err);
+	}
+
+	event->pmu = pmu;
+
+	if (!event->parent) {
+		atomic_inc(&nr_events);
+		if (event->attr.mmap)
+			atomic_inc(&nr_mmap_events);
+		if (event->attr.comm)
+			atomic_inc(&nr_comm_events);
+		if (event->attr.task)
+			atomic_inc(&nr_task_events);
+	}
+
+	return event;
+}
+
+static int perf_copy_attr(struct perf_event_attr __user *uattr,
+			  struct perf_event_attr *attr)
+{
+	u32 size;
+	int ret;
+
+	if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0))
+		return -EFAULT;
+
+	/*
+	 * zero the full structure, so that a short copy will be nice.
+	 */
+	memset(attr, 0, sizeof(*attr));
+
+	ret = get_user(size, &uattr->size);
+	if (ret)
+		return ret;
+
+	if (size > PAGE_SIZE)	/* silly large */
+		goto err_size;
+
+	if (!size)		/* abi compat */
+		size = PERF_ATTR_SIZE_VER0;
+
+	if (size < PERF_ATTR_SIZE_VER0)
+		goto err_size;
+
+	/*
+	 * If we're handed a bigger struct than we know of,
+	 * ensure all the unknown bits are 0 - i.e. new
+	 * user-space does not rely on any kernel feature
+	 * extensions we dont know about yet.
+	 */
+	if (size > sizeof(*attr)) {
+		unsigned char __user *addr;
+		unsigned char __user *end;
+		unsigned char val;
+
+		addr = (void __user *)uattr + sizeof(*attr);
+		end  = (void __user *)uattr + size;
+
+		for (; addr < end; addr++) {
+			ret = get_user(val, addr);
+			if (ret)
+				return ret;
+			if (val)
+				goto err_size;
+		}
+		size = sizeof(*attr);
+	}
+
+	ret = copy_from_user(attr, uattr, size);
+	if (ret)
+		return -EFAULT;
+
+	/*
+	 * If the type exists, the corresponding creation will verify
+	 * the attr->config.
+	 */
+	if (attr->type >= PERF_TYPE_MAX)
+		return -EINVAL;
+
+	if (attr->__reserved_1 || attr->__reserved_2 || attr->__reserved_3)
+		return -EINVAL;
+
+	if (attr->sample_type & ~(PERF_SAMPLE_MAX-1))
+		return -EINVAL;
+
+	if (attr->read_format & ~(PERF_FORMAT_MAX-1))
+		return -EINVAL;
+
+out:
+	return ret;
+
+err_size:
+	put_user(sizeof(*attr), &uattr->size);
+	ret = -E2BIG;
+	goto out;
+}
+
+int perf_event_set_output(struct perf_event *event, int output_fd)
+{
+	struct perf_event *output_event = NULL;
+	struct file *output_file = NULL;
+	struct perf_event *old_output;
+	int fput_needed = 0;
+	int ret = -EINVAL;
+
+	if (!output_fd)
+		goto set;
+
+	output_file = fget_light(output_fd, &fput_needed);
+	if (!output_file)
+		return -EBADF;
+
+	if (output_file->f_op != &perf_fops)
+		goto out;
+
+	output_event = output_file->private_data;
+
+	/* Don't chain output fds */
+	if (output_event->output)
+		goto out;
+
+	/* Don't set an output fd when we already have an output channel */
+	if (event->data)
+		goto out;
+
+	atomic_long_inc(&output_file->f_count);
+
+set:
+	mutex_lock(&event->mmap_mutex);
+	old_output = event->output;
+	rcu_assign_pointer(event->output, output_event);
+	mutex_unlock(&event->mmap_mutex);
+
+	if (old_output) {
+		/*
+		 * we need to make sure no existing perf_output_*()
+		 * is still referencing this event.
+		 */
+		synchronize_rcu();
+		fput(old_output->filp);
+	}
+
+	ret = 0;
+out:
+	fput_light(output_file, fput_needed);
+	return ret;
+}
+
+/**
+ * sys_perf_event_open - open a performance event, associate it to a task/cpu
+ *
+ * @attr_uptr:	event_id type attributes for monitoring/sampling
+ * @pid:		target pid
+ * @cpu:		target cpu
+ * @group_fd:		group leader event fd
+ */
+SYSCALL_DEFINE5(perf_event_open,
+		struct perf_event_attr __user *, attr_uptr,
+		pid_t, pid, int, cpu, int, group_fd, unsigned long, flags)
+{
+	struct perf_event *event, *group_leader;
+	struct perf_event_attr attr;
+	struct perf_event_context *ctx;
+	struct file *event_file = NULL;
+	struct file *group_file = NULL;
+	int fput_needed = 0;
+	int fput_needed2 = 0;
+	int err;
+
+	/* for future expandability... */
+	if (flags & ~(PERF_FLAG_FD_NO_GROUP | PERF_FLAG_FD_OUTPUT))
+		return -EINVAL;
+
+	err = perf_copy_attr(attr_uptr, &attr);
+	if (err)
+		return err;
+
+	if (!attr.exclude_kernel) {
+		if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN))
+			return -EACCES;
+	}
+
+	if (attr.freq) {
+		if (attr.sample_freq > sysctl_perf_event_sample_rate)
+			return -EINVAL;
+	}
+
+	/*
+	 * Get the target context (task or percpu):
+	 */
+	ctx = find_get_context(pid, cpu);
+	if (IS_ERR(ctx))
+		return PTR_ERR(ctx);
+
+	/*
+	 * Look up the group leader (we will attach this event to it):
+	 */
+	group_leader = NULL;
+	if (group_fd != -1 && !(flags & PERF_FLAG_FD_NO_GROUP)) {
+		err = -EINVAL;
+		group_file = fget_light(group_fd, &fput_needed);
+		if (!group_file)
+			goto err_put_context;
+		if (group_file->f_op != &perf_fops)
+			goto err_put_context;
+
+		group_leader = group_file->private_data;
+		/*
+		 * Do not allow a recursive hierarchy (this new sibling
+		 * becoming part of another group-sibling):
+		 */
+		if (group_leader->group_leader != group_leader)
+			goto err_put_context;
+		/*
+		 * Do not allow to attach to a group in a different
+		 * task or CPU context:
+		 */
+		if (group_leader->ctx != ctx)
+			goto err_put_context;
+		/*
+		 * Only a group leader can be exclusive or pinned
+		 */
+		if (attr.exclusive || attr.pinned)
+			goto err_put_context;
+	}
+
+	event = perf_event_alloc(&attr, cpu, ctx, group_leader,
+				     NULL, GFP_KERNEL);
+	err = PTR_ERR(event);
+	if (IS_ERR(event))
+		goto err_put_context;
+
+	err = anon_inode_getfd("[perf_event]", &perf_fops, event, 0);
+	if (err < 0)
+		goto err_free_put_context;
+
+	event_file = fget_light(err, &fput_needed2);
+	if (!event_file)
+		goto err_free_put_context;
+
+	if (flags & PERF_FLAG_FD_OUTPUT) {
+		err = perf_event_set_output(event, group_fd);
+		if (err)
+			goto err_fput_free_put_context;
+	}
+
+	event->filp = event_file;
+	WARN_ON_ONCE(ctx->parent_ctx);
+	mutex_lock(&ctx->mutex);
+	perf_install_in_context(ctx, event, cpu);
+	++ctx->generation;
+	mutex_unlock(&ctx->mutex);
+
+	event->owner = current;
+	get_task_struct(current);
+	mutex_lock(&current->perf_event_mutex);
+	list_add_tail(&event->owner_entry, &current->perf_event_list);
+	mutex_unlock(&current->perf_event_mutex);
+
+err_fput_free_put_context:
+	fput_light(event_file, fput_needed2);
+
+err_free_put_context:
+	if (err < 0)
+		kfree(event);
+
+err_put_context:
+	if (err < 0)
+		put_ctx(ctx);
+
+	fput_light(group_file, fput_needed);
+
+	return err;
+}
+
+/*
+ * inherit a event from parent task to child task:
+ */
+static struct perf_event *
+inherit_event(struct perf_event *parent_event,
+	      struct task_struct *parent,
+	      struct perf_event_context *parent_ctx,
+	      struct task_struct *child,
+	      struct perf_event *group_leader,
+	      struct perf_event_context *child_ctx)
+{
+	struct perf_event *child_event;
+
+	/*
+	 * Instead of creating recursive hierarchies of events,
+	 * we link inherited events back to the original parent,
+	 * which has a filp for sure, which we use as the reference
+	 * count:
+	 */
+	if (parent_event->parent)
+		parent_event = parent_event->parent;
+
+	child_event = perf_event_alloc(&parent_event->attr,
+					   parent_event->cpu, child_ctx,
+					   group_leader, parent_event,
+					   GFP_KERNEL);
+	if (IS_ERR(child_event))
+		return child_event;
+	get_ctx(child_ctx);
+
+	/*
+	 * Make the child state follow the state of the parent event,
+	 * not its attr.disabled bit.  We hold the parent's mutex,
+	 * so we won't race with perf_event_{en, dis}able_family.
+	 */
+	if (parent_event->state >= PERF_EVENT_STATE_INACTIVE)
+		child_event->state = PERF_EVENT_STATE_INACTIVE;
+	else
+		child_event->state = PERF_EVENT_STATE_OFF;
+
+	if (parent_event->attr.freq)
+		child_event->hw.sample_period = parent_event->hw.sample_period;
+
+	/*
+	 * Link it up in the child's context:
+	 */
+	add_event_to_ctx(child_event, child_ctx);
+
+	/*
+	 * Get a reference to the parent filp - we will fput it
+	 * when the child event exits. This is safe to do because
+	 * we are in the parent and we know that the filp still
+	 * exists and has a nonzero count:
+	 */
+	atomic_long_inc(&parent_event->filp->f_count);
+
+	/*
+	 * Link this into the parent event's child list
+	 */
+	WARN_ON_ONCE(parent_event->ctx->parent_ctx);
+	mutex_lock(&parent_event->child_mutex);
+	list_add_tail(&child_event->child_list, &parent_event->child_list);
+	mutex_unlock(&parent_event->child_mutex);
+
+	return child_event;
+}
+
+static int inherit_group(struct perf_event *parent_event,
+	      struct task_struct *parent,
+	      struct perf_event_context *parent_ctx,
+	      struct task_struct *child,
+	      struct perf_event_context *child_ctx)
+{
+	struct perf_event *leader;
+	struct perf_event *sub;
+	struct perf_event *child_ctr;
+
+	leader = inherit_event(parent_event, parent, parent_ctx,
+				 child, NULL, child_ctx);
+	if (IS_ERR(leader))
+		return PTR_ERR(leader);
+	list_for_each_entry(sub, &parent_event->sibling_list, group_entry) {
+		child_ctr = inherit_event(sub, parent, parent_ctx,
+					    child, leader, child_ctx);
+		if (IS_ERR(child_ctr))
+			return PTR_ERR(child_ctr);
+	}
+	return 0;
+}
+
+static void sync_child_event(struct perf_event *child_event,
+			       struct task_struct *child)
+{
+	struct perf_event *parent_event = child_event->parent;
+	u64 child_val;
+
+	if (child_event->attr.inherit_stat)
+		perf_event_read_event(child_event, child);
+
+	child_val = atomic64_read(&child_event->count);
+
+	/*
+	 * Add back the child's count to the parent's count:
+	 */
+	atomic64_add(child_val, &parent_event->count);
+	atomic64_add(child_event->total_time_enabled,
+		     &parent_event->child_total_time_enabled);
+	atomic64_add(child_event->total_time_running,
+		     &parent_event->child_total_time_running);
+
+	/*
+	 * Remove this event from the parent's list
+	 */
+	WARN_ON_ONCE(parent_event->ctx->parent_ctx);
+	mutex_lock(&parent_event->child_mutex);
+	list_del_init(&child_event->child_list);
+	mutex_unlock(&parent_event->child_mutex);
+
+	/*
+	 * Release the parent event, if this was the last
+	 * reference to it.
+	 */
+	fput(parent_event->filp);
+}
+
+static void
+__perf_event_exit_task(struct perf_event *child_event,
+			 struct perf_event_context *child_ctx,
+			 struct task_struct *child)
+{
+	struct perf_event *parent_event;
+
+	update_event_times(child_event);
+	perf_event_remove_from_context(child_event);
+
+	parent_event = child_event->parent;
+	/*
+	 * It can happen that parent exits first, and has events
+	 * that are still around due to the child reference. These
+	 * events need to be zapped - but otherwise linger.
+	 */
+	if (parent_event) {
+		sync_child_event(child_event, child);
+		free_event(child_event);
+	}
+}
+
+/*
+ * When a child task exits, feed back event values to parent events.
+ */
+void perf_event_exit_task(struct task_struct *child)
+{
+	struct perf_event *child_event, *tmp;
+	struct perf_event_context *child_ctx;
+	unsigned long flags;
+
+	if (likely(!child->perf_event_ctxp)) {
+		perf_event_task(child, NULL, 0);
+		return;
+	}
+
+	local_irq_save(flags);
+	/*
+	 * We can't reschedule here because interrupts are disabled,
+	 * and either child is current or it is a task that can't be
+	 * scheduled, so we are now safe from rescheduling changing
+	 * our context.
+	 */
+	child_ctx = child->perf_event_ctxp;
+	__perf_event_task_sched_out(child_ctx);
+
+	/*
+	 * Take the context lock here so that if find_get_context is
+	 * reading child->perf_event_ctxp, we wait until it has
+	 * incremented the context's refcount before we do put_ctx below.
+	 */
+	spin_lock(&child_ctx->lock);
+	child->perf_event_ctxp = NULL;
+	/*
+	 * If this context is a clone; unclone it so it can't get
+	 * swapped to another process while we're removing all
+	 * the events from it.
+	 */
+	unclone_ctx(child_ctx);
+	spin_unlock_irqrestore(&child_ctx->lock, flags);
+
+	/*
+	 * Report the task dead after unscheduling the events so that we
+	 * won't get any samples after PERF_RECORD_EXIT. We can however still
+	 * get a few PERF_RECORD_READ events.
+	 */
+	perf_event_task(child, child_ctx, 0);
+
+	/*
+	 * We can recurse on the same lock type through:
+	 *
+	 *   __perf_event_exit_task()
+	 *     sync_child_event()
+	 *       fput(parent_event->filp)
+	 *         perf_release()
+	 *           mutex_lock(&ctx->mutex)
+	 *
+	 * But since its the parent context it won't be the same instance.
+	 */
+	mutex_lock_nested(&child_ctx->mutex, SINGLE_DEPTH_NESTING);
+
+again:
+	list_for_each_entry_safe(child_event, tmp, &child_ctx->group_list,
+				 group_entry)
+		__perf_event_exit_task(child_event, child_ctx, child);
+
+	/*
+	 * If the last event was a group event, it will have appended all
+	 * its siblings to the list, but we obtained 'tmp' before that which
+	 * will still point to the list head terminating the iteration.
+	 */
+	if (!list_empty(&child_ctx->group_list))
+		goto again;
+
+	mutex_unlock(&child_ctx->mutex);
+
+	put_ctx(child_ctx);
+}
+
+/*
+ * free an unexposed, unused context as created by inheritance by
+ * init_task below, used by fork() in case of fail.
+ */
+void perf_event_free_task(struct task_struct *task)
+{
+	struct perf_event_context *ctx = task->perf_event_ctxp;
+	struct perf_event *event, *tmp;
+
+	if (!ctx)
+		return;
+
+	mutex_lock(&ctx->mutex);
+again:
+	list_for_each_entry_safe(event, tmp, &ctx->group_list, group_entry) {
+		struct perf_event *parent = event->parent;
+
+		if (WARN_ON_ONCE(!parent))
+			continue;
+
+		mutex_lock(&parent->child_mutex);
+		list_del_init(&event->child_list);
+		mutex_unlock(&parent->child_mutex);
+
+		fput(parent->filp);
+
+		list_del_event(event, ctx);
+		free_event(event);
+	}
+
+	if (!list_empty(&ctx->group_list))
+		goto again;
+
+	mutex_unlock(&ctx->mutex);
+
+	put_ctx(ctx);
+}
+
+/*
+ * Initialize the perf_event context in task_struct
+ */
+int perf_event_init_task(struct task_struct *child)
+{
+	struct perf_event_context *child_ctx, *parent_ctx;
+	struct perf_event_context *cloned_ctx;
+	struct perf_event *event;
+	struct task_struct *parent = current;
+	int inherited_all = 1;
+	int ret = 0;
+
+	child->perf_event_ctxp = NULL;
+
+	mutex_init(&child->perf_event_mutex);
+	INIT_LIST_HEAD(&child->perf_event_list);
+
+	if (likely(!parent->perf_event_ctxp))
+		return 0;
+
+	/*
+	 * This is executed from the parent task context, so inherit
+	 * events that have been marked for cloning.
+	 * First allocate and initialize a context for the child.
+	 */
+
+	child_ctx = kmalloc(sizeof(struct perf_event_context), GFP_KERNEL);
+	if (!child_ctx)
+		return -ENOMEM;
+
+	__perf_event_init_context(child_ctx, child);
+	child->perf_event_ctxp = child_ctx;
+	get_task_struct(child);
+
+	/*
+	 * If the parent's context is a clone, pin it so it won't get
+	 * swapped under us.
+	 */
+	parent_ctx = perf_pin_task_context(parent);
+
+	/*
+	 * No need to check if parent_ctx != NULL here; since we saw
+	 * it non-NULL earlier, the only reason for it to become NULL
+	 * is if we exit, and since we're currently in the middle of
+	 * a fork we can't be exiting at the same time.
+	 */
+
+	/*
+	 * Lock the parent list. No need to lock the child - not PID
+	 * hashed yet and not running, so nobody can access it.
+	 */
+	mutex_lock(&parent_ctx->mutex);
+
+	/*
+	 * We dont have to disable NMIs - we are only looking at
+	 * the list, not manipulating it:
+	 */
+	list_for_each_entry(event, &parent_ctx->group_list, group_entry) {
+
+		if (!event->attr.inherit) {
+			inherited_all = 0;
+			continue;
+		}
+
+		ret = inherit_group(event, parent, parent_ctx,
+					     child, child_ctx);
+		if (ret) {
+			inherited_all = 0;
+			break;
+		}
+	}
+
+	if (inherited_all) {
+		/*
+		 * Mark the child context as a clone of the parent
+		 * context, or of whatever the parent is a clone of.
+		 * Note that if the parent is a clone, it could get
+		 * uncloned at any point, but that doesn't matter
+		 * because the list of events and the generation
+		 * count can't have changed since we took the mutex.
+		 */
+		cloned_ctx = rcu_dereference(parent_ctx->parent_ctx);
+		if (cloned_ctx) {
+			child_ctx->parent_ctx = cloned_ctx;
+			child_ctx->parent_gen = parent_ctx->parent_gen;
+		} else {
+			child_ctx->parent_ctx = parent_ctx;
+			child_ctx->parent_gen = parent_ctx->generation;
+		}
+		get_ctx(child_ctx->parent_ctx);
+	}
+
+	mutex_unlock(&parent_ctx->mutex);
+
+	perf_unpin_context(parent_ctx);
+
+	return ret;
+}
+
+static void __cpuinit perf_event_init_cpu(int cpu)
+{
+	struct perf_cpu_context *cpuctx;
+
+	cpuctx = &per_cpu(perf_cpu_context, cpu);
+	__perf_event_init_context(&cpuctx->ctx, NULL);
+
+	spin_lock(&perf_resource_lock);
+	cpuctx->max_pertask = perf_max_events - perf_reserved_percpu;
+	spin_unlock(&perf_resource_lock);
+
+	hw_perf_event_setup(cpu);
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+static void __perf_event_exit_cpu(void *info)
+{
+	struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
+	struct perf_event_context *ctx = &cpuctx->ctx;
+	struct perf_event *event, *tmp;
+
+	list_for_each_entry_safe(event, tmp, &ctx->group_list, group_entry)
+		__perf_event_remove_from_context(event);
+}
+static void perf_event_exit_cpu(int cpu)
+{
+	struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu);
+	struct perf_event_context *ctx = &cpuctx->ctx;
+
+	mutex_lock(&ctx->mutex);
+	smp_call_function_single(cpu, __perf_event_exit_cpu, NULL, 1);
+	mutex_unlock(&ctx->mutex);
+}
+#else
+static inline void perf_event_exit_cpu(int cpu) { }
+#endif
+
+static int __cpuinit
+perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu)
+{
+	unsigned int cpu = (long)hcpu;
+
+	switch (action) {
+
+	case CPU_UP_PREPARE:
+	case CPU_UP_PREPARE_FROZEN:
+		perf_event_init_cpu(cpu);
+		break;
+
+	case CPU_ONLINE:
+	case CPU_ONLINE_FROZEN:
+		hw_perf_event_setup_online(cpu);
+		break;
+
+	case CPU_DOWN_PREPARE:
+	case CPU_DOWN_PREPARE_FROZEN:
+		perf_event_exit_cpu(cpu);
+		break;
+
+	default:
+		break;
+	}
+
+	return NOTIFY_OK;
+}
+
+/*
+ * This has to have a higher priority than migration_notifier in sched.c.
+ */
+static struct notifier_block __cpuinitdata perf_cpu_nb = {
+	.notifier_call		= perf_cpu_notify,
+	.priority		= 20,
+};
+
+void __init perf_event_init(void)
+{
+	perf_cpu_notify(&perf_cpu_nb, (unsigned long)CPU_UP_PREPARE,
+			(void *)(long)smp_processor_id());
+	perf_cpu_notify(&perf_cpu_nb, (unsigned long)CPU_ONLINE,
+			(void *)(long)smp_processor_id());
+	register_cpu_notifier(&perf_cpu_nb);
+}
+
+static ssize_t perf_show_reserve_percpu(struct sysdev_class *class, char *buf)
+{
+	return sprintf(buf, "%d\n", perf_reserved_percpu);
+}
+
+static ssize_t
+perf_set_reserve_percpu(struct sysdev_class *class,
+			const char *buf,
+			size_t count)
+{
+	struct perf_cpu_context *cpuctx;
+	unsigned long val;
+	int err, cpu, mpt;
+
+	err = strict_strtoul(buf, 10, &val);
+	if (err)
+		return err;
+	if (val > perf_max_events)
+		return -EINVAL;
+
+	spin_lock(&perf_resource_lock);
+	perf_reserved_percpu = val;
+	for_each_online_cpu(cpu) {
+		cpuctx = &per_cpu(perf_cpu_context, cpu);
+		spin_lock_irq(&cpuctx->ctx.lock);
+		mpt = min(perf_max_events - cpuctx->ctx.nr_events,
+			  perf_max_events - perf_reserved_percpu);
+		cpuctx->max_pertask = mpt;
+		spin_unlock_irq(&cpuctx->ctx.lock);
+	}
+	spin_unlock(&perf_resource_lock);
+
+	return count;
+}
+
+static ssize_t perf_show_overcommit(struct sysdev_class *class, char *buf)
+{
+	return sprintf(buf, "%d\n", perf_overcommit);
+}
+
+static ssize_t
+perf_set_overcommit(struct sysdev_class *class, const char *buf, size_t count)
+{
+	unsigned long val;
+	int err;
+
+	err = strict_strtoul(buf, 10, &val);
+	if (err)
+		return err;
+	if (val > 1)
+		return -EINVAL;
+
+	spin_lock(&perf_resource_lock);
+	perf_overcommit = val;
+	spin_unlock(&perf_resource_lock);
+
+	return count;
+}
+
+static SYSDEV_CLASS_ATTR(
+				reserve_percpu,
+				0644,
+				perf_show_reserve_percpu,
+				perf_set_reserve_percpu
+			);
+
+static SYSDEV_CLASS_ATTR(
+				overcommit,
+				0644,
+				perf_show_overcommit,
+				perf_set_overcommit
+			);
+
+static struct attribute *perfclass_attrs[] = {
+	&attr_reserve_percpu.attr,
+	&attr_overcommit.attr,
+	NULL
+};
+
+static struct attribute_group perfclass_attr_group = {
+	.attrs			= perfclass_attrs,
+	.name			= "perf_events",
+};
+
+static int __init perf_event_sysfs_init(void)
+{
+	return sysfs_create_group(&cpu_sysdev_class.kset.kobj,
+				  &perfclass_attr_group);
+}
+device_initcall(perf_event_sysfs_init);
diff --git a/kernel/pid.c b/kernel/pid.c
index 31310b5d3f5..d3f722d20f9 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -40,7 +40,7 @@
 #define pid_hashfn(nr, ns)	\
 	hash_long((unsigned long)nr + (unsigned long)ns, pidhash_shift)
 static struct hlist_head *pid_hash;
-static int pidhash_shift;
+static unsigned int pidhash_shift = 4;
 struct pid init_struct_pid = INIT_STRUCT_PID;
 
 int pid_max = PID_MAX_DEFAULT;
@@ -499,19 +499,12 @@ struct pid *find_ge_pid(int nr, struct pid_namespace *ns)
 void __init pidhash_init(void)
 {
 	int i, pidhash_size;
-	unsigned long megabytes = nr_kernel_pages >> (20 - PAGE_SHIFT);
 
-	pidhash_shift = max(4, fls(megabytes * 4));
-	pidhash_shift = min(12, pidhash_shift);
+	pid_hash = alloc_large_system_hash("PID", sizeof(*pid_hash), 0, 18,
+					   HASH_EARLY | HASH_SMALL,
+					   &pidhash_shift, NULL, 4096);
 	pidhash_size = 1 << pidhash_shift;
 
-	printk("PID hash table entries: %d (order: %d, %Zd bytes)\n",
-		pidhash_size, pidhash_shift,
-		pidhash_size * sizeof(struct hlist_head));
-
-	pid_hash = alloc_bootmem(pidhash_size *	sizeof(*(pid_hash)));
-	if (!pid_hash)
-		panic("Could not alloc pidhash!\n");
 	for (i = 0; i < pidhash_size; i++)
 		INIT_HLIST_HEAD(&pid_hash[i]);
 }
diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c
index 821722ae58a..86b3796b043 100644
--- a/kernel/pid_namespace.c
+++ b/kernel/pid_namespace.c
@@ -118,7 +118,7 @@ struct pid_namespace *copy_pid_ns(unsigned long flags, struct pid_namespace *old
 {
 	if (!(flags & CLONE_NEWPID))
 		return get_pid_ns(old_ns);
-	if (flags & CLONE_THREAD)
+	if (flags & (CLONE_THREAD|CLONE_PARENT))
 		return ERR_PTR(-EINVAL);
 	return create_pid_namespace(old_ns);
 }
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index e33a21cb940..5c9dc228747 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -8,17 +8,18 @@
 #include <linux/math64.h>
 #include <asm/uaccess.h>
 #include <linux/kernel_stat.h>
+#include <trace/events/timer.h>
 
 /*
  * Called after updating RLIMIT_CPU to set timer expiration if necessary.
  */
 void update_rlimit_cpu(unsigned long rlim_new)
 {
-	cputime_t cputime;
+	cputime_t cputime = secs_to_cputime(rlim_new);
+	struct signal_struct *const sig = current->signal;
 
-	cputime = secs_to_cputime(rlim_new);
-	if (cputime_eq(current->signal->it_prof_expires, cputime_zero) ||
-	    cputime_gt(current->signal->it_prof_expires, cputime)) {
+	if (cputime_eq(sig->it[CPUCLOCK_PROF].expires, cputime_zero) ||
+	    cputime_gt(sig->it[CPUCLOCK_PROF].expires, cputime)) {
 		spin_lock_irq(&current->sighand->siglock);
 		set_process_cpu_timer(current, CPUCLOCK_PROF, &cputime, NULL);
 		spin_unlock_irq(&current->sighand->siglock);
@@ -542,6 +543,17 @@ static void clear_dead_task(struct k_itimer *timer, union cpu_time_count now)
 					     now);
 }
 
+static inline int expires_gt(cputime_t expires, cputime_t new_exp)
+{
+	return cputime_eq(expires, cputime_zero) ||
+	       cputime_gt(expires, new_exp);
+}
+
+static inline int expires_le(cputime_t expires, cputime_t new_exp)
+{
+	return !cputime_eq(expires, cputime_zero) &&
+	       cputime_le(expires, new_exp);
+}
 /*
  * Insert the timer on the appropriate list before any timers that
  * expire later.  This must be called with the tasklist_lock held
@@ -586,34 +598,32 @@ static void arm_timer(struct k_itimer *timer, union cpu_time_count now)
 		 */
 
 		if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
+			union cpu_time_count *exp = &nt->expires;
+
 			switch (CPUCLOCK_WHICH(timer->it_clock)) {
 			default:
 				BUG();
 			case CPUCLOCK_PROF:
-				if (cputime_eq(p->cputime_expires.prof_exp,
-					       cputime_zero) ||
-				    cputime_gt(p->cputime_expires.prof_exp,
-					       nt->expires.cpu))
-					p->cputime_expires.prof_exp =
-						nt->expires.cpu;
+				if (expires_gt(p->cputime_expires.prof_exp,
+					       exp->cpu))
+					p->cputime_expires.prof_exp = exp->cpu;
 				break;
 			case CPUCLOCK_VIRT:
-				if (cputime_eq(p->cputime_expires.virt_exp,
-					       cputime_zero) ||
-				    cputime_gt(p->cputime_expires.virt_exp,
-					       nt->expires.cpu))
-					p->cputime_expires.virt_exp =
-						nt->expires.cpu;
+				if (expires_gt(p->cputime_expires.virt_exp,
+					       exp->cpu))
+					p->cputime_expires.virt_exp = exp->cpu;
 				break;
 			case CPUCLOCK_SCHED:
 				if (p->cputime_expires.sched_exp == 0 ||
-				    p->cputime_expires.sched_exp >
-							nt->expires.sched)
+				    p->cputime_expires.sched_exp > exp->sched)
 					p->cputime_expires.sched_exp =
-						nt->expires.sched;
+								exp->sched;
 				break;
 			}
 		} else {
+			struct signal_struct *const sig = p->signal;
+			union cpu_time_count *exp = &timer->it.cpu.expires;
+
 			/*
 			 * For a process timer, set the cached expiration time.
 			 */
@@ -621,30 +631,23 @@ static void arm_timer(struct k_itimer *timer, union cpu_time_count now)
 			default:
 				BUG();
 			case CPUCLOCK_VIRT:
-				if (!cputime_eq(p->signal->it_virt_expires,
-						cputime_zero) &&
-				    cputime_lt(p->signal->it_virt_expires,
-					       timer->it.cpu.expires.cpu))
+				if (expires_le(sig->it[CPUCLOCK_VIRT].expires,
+					       exp->cpu))
 					break;
-				p->signal->cputime_expires.virt_exp =
-					timer->it.cpu.expires.cpu;
+				sig->cputime_expires.virt_exp = exp->cpu;
 				break;
 			case CPUCLOCK_PROF:
-				if (!cputime_eq(p->signal->it_prof_expires,
-						cputime_zero) &&
-				    cputime_lt(p->signal->it_prof_expires,
-					       timer->it.cpu.expires.cpu))
+				if (expires_le(sig->it[CPUCLOCK_PROF].expires,
+					       exp->cpu))
 					break;
-				i = p->signal->rlim[RLIMIT_CPU].rlim_cur;
+				i = sig->rlim[RLIMIT_CPU].rlim_cur;
 				if (i != RLIM_INFINITY &&
-				    i <= cputime_to_secs(timer->it.cpu.expires.cpu))
+				    i <= cputime_to_secs(exp->cpu))
 					break;
-				p->signal->cputime_expires.prof_exp =
-					timer->it.cpu.expires.cpu;
+				sig->cputime_expires.prof_exp = exp->cpu;
 				break;
 			case CPUCLOCK_SCHED:
-				p->signal->cputime_expires.sched_exp =
-					timer->it.cpu.expires.sched;
+				sig->cputime_expires.sched_exp = exp->sched;
 				break;
 			}
 		}
@@ -1071,6 +1074,40 @@ static void stop_process_timers(struct task_struct *tsk)
 	spin_unlock_irqrestore(&cputimer->lock, flags);
 }
 
+static u32 onecputick;
+
+static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it,
+			     cputime_t *expires, cputime_t cur_time, int signo)
+{
+	if (cputime_eq(it->expires, cputime_zero))
+		return;
+
+	if (cputime_ge(cur_time, it->expires)) {
+		if (!cputime_eq(it->incr, cputime_zero)) {
+			it->expires = cputime_add(it->expires, it->incr);
+			it->error += it->incr_error;
+			if (it->error >= onecputick) {
+				it->expires = cputime_sub(it->expires,
+							  cputime_one_jiffy);
+				it->error -= onecputick;
+			}
+		} else {
+			it->expires = cputime_zero;
+		}
+
+		trace_itimer_expire(signo == SIGPROF ?
+				    ITIMER_PROF : ITIMER_VIRTUAL,
+				    tsk->signal->leader_pid, cur_time);
+		__group_send_sig_info(signo, SEND_SIG_PRIV, tsk);
+	}
+
+	if (!cputime_eq(it->expires, cputime_zero) &&
+	    (cputime_eq(*expires, cputime_zero) ||
+	     cputime_lt(it->expires, *expires))) {
+		*expires = it->expires;
+	}
+}
+
 /*
  * Check for any per-thread CPU timers that have fired and move them
  * off the tsk->*_timers list onto the firing list.  Per-thread timers
@@ -1090,10 +1127,10 @@ static void check_process_timers(struct task_struct *tsk,
 	 * Don't sample the current process CPU clocks if there are no timers.
 	 */
 	if (list_empty(&timers[CPUCLOCK_PROF]) &&
-	    cputime_eq(sig->it_prof_expires, cputime_zero) &&
+	    cputime_eq(sig->it[CPUCLOCK_PROF].expires, cputime_zero) &&
 	    sig->rlim[RLIMIT_CPU].rlim_cur == RLIM_INFINITY &&
 	    list_empty(&timers[CPUCLOCK_VIRT]) &&
-	    cputime_eq(sig->it_virt_expires, cputime_zero) &&
+	    cputime_eq(sig->it[CPUCLOCK_VIRT].expires, cputime_zero) &&
 	    list_empty(&timers[CPUCLOCK_SCHED])) {
 		stop_process_timers(tsk);
 		return;
@@ -1153,38 +1190,11 @@ static void check_process_timers(struct task_struct *tsk,
 	/*
 	 * Check for the special case process timers.
 	 */
-	if (!cputime_eq(sig->it_prof_expires, cputime_zero)) {
-		if (cputime_ge(ptime, sig->it_prof_expires)) {
-			/* ITIMER_PROF fires and reloads.  */
-			sig->it_prof_expires = sig->it_prof_incr;
-			if (!cputime_eq(sig->it_prof_expires, cputime_zero)) {
-				sig->it_prof_expires = cputime_add(
-					sig->it_prof_expires, ptime);
-			}
-			__group_send_sig_info(SIGPROF, SEND_SIG_PRIV, tsk);
-		}
-		if (!cputime_eq(sig->it_prof_expires, cputime_zero) &&
-		    (cputime_eq(prof_expires, cputime_zero) ||
-		     cputime_lt(sig->it_prof_expires, prof_expires))) {
-			prof_expires = sig->it_prof_expires;
-		}
-	}
-	if (!cputime_eq(sig->it_virt_expires, cputime_zero)) {
-		if (cputime_ge(utime, sig->it_virt_expires)) {
-			/* ITIMER_VIRTUAL fires and reloads.  */
-			sig->it_virt_expires = sig->it_virt_incr;
-			if (!cputime_eq(sig->it_virt_expires, cputime_zero)) {
-				sig->it_virt_expires = cputime_add(
-					sig->it_virt_expires, utime);
-			}
-			__group_send_sig_info(SIGVTALRM, SEND_SIG_PRIV, tsk);
-		}
-		if (!cputime_eq(sig->it_virt_expires, cputime_zero) &&
-		    (cputime_eq(virt_expires, cputime_zero) ||
-		     cputime_lt(sig->it_virt_expires, virt_expires))) {
-			virt_expires = sig->it_virt_expires;
-		}
-	}
+	check_cpu_itimer(tsk, &sig->it[CPUCLOCK_PROF], &prof_expires, ptime,
+			 SIGPROF);
+	check_cpu_itimer(tsk, &sig->it[CPUCLOCK_VIRT], &virt_expires, utime,
+			 SIGVTALRM);
+
 	if (sig->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) {
 		unsigned long psecs = cputime_to_secs(ptime);
 		cputime_t x;
@@ -1457,7 +1467,7 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx,
 		if (!cputime_eq(*oldval, cputime_zero)) {
 			if (cputime_le(*oldval, now.cpu)) {
 				/* Just about to fire. */
-				*oldval = jiffies_to_cputime(1);
+				*oldval = cputime_one_jiffy;
 			} else {
 				*oldval = cputime_sub(*oldval, now.cpu);
 			}
@@ -1703,10 +1713,15 @@ static __init int init_posix_cpu_timers(void)
 		.nsleep = thread_cpu_nsleep,
 		.nsleep_restart = thread_cpu_nsleep_restart,
 	};
+	struct timespec ts;
 
 	register_posix_clock(CLOCK_PROCESS_CPUTIME_ID, &process);
 	register_posix_clock(CLOCK_THREAD_CPUTIME_ID, &thread);
 
+	cputime_to_timespec(cputime_one_jiffy, &ts);
+	onecputick = ts.tv_nsec;
+	WARN_ON(ts.tv_sec != 0);
+
 	return 0;
 }
 __initcall(init_posix_cpu_timers);
diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
index d089d052c4a..495440779ce 100644
--- a/kernel/posix-timers.c
+++ b/kernel/posix-timers.c
@@ -242,6 +242,25 @@ static int posix_get_monotonic_raw(clockid_t which_clock, struct timespec *tp)
 	return 0;
 }
 
+
+static int posix_get_realtime_coarse(clockid_t which_clock, struct timespec *tp)
+{
+	*tp = current_kernel_time();
+	return 0;
+}
+
+static int posix_get_monotonic_coarse(clockid_t which_clock,
+						struct timespec *tp)
+{
+	*tp = get_monotonic_coarse();
+	return 0;
+}
+
+int posix_get_coarse_res(const clockid_t which_clock, struct timespec *tp)
+{
+	*tp = ktime_to_timespec(KTIME_LOW_RES);
+	return 0;
+}
 /*
  * Initialize everything, well, just everything in Posix clocks/timers ;)
  */
@@ -262,10 +281,26 @@ static __init int init_posix_timers(void)
 		.timer_create = no_timer_create,
 		.nsleep = no_nsleep,
 	};
+	struct k_clock clock_realtime_coarse = {
+		.clock_getres = posix_get_coarse_res,
+		.clock_get = posix_get_realtime_coarse,
+		.clock_set = do_posix_clock_nosettime,
+		.timer_create = no_timer_create,
+		.nsleep = no_nsleep,
+	};
+	struct k_clock clock_monotonic_coarse = {
+		.clock_getres = posix_get_coarse_res,
+		.clock_get = posix_get_monotonic_coarse,
+		.clock_set = do_posix_clock_nosettime,
+		.timer_create = no_timer_create,
+		.nsleep = no_nsleep,
+	};
 
 	register_posix_clock(CLOCK_REALTIME, &clock_realtime);
 	register_posix_clock(CLOCK_MONOTONIC, &clock_monotonic);
 	register_posix_clock(CLOCK_MONOTONIC_RAW, &clock_monotonic_raw);
+	register_posix_clock(CLOCK_REALTIME_COARSE, &clock_realtime_coarse);
+	register_posix_clock(CLOCK_MONOTONIC_COARSE, &clock_monotonic_coarse);
 
 	posix_timers_cache = kmem_cache_create("posix_timers_cache",
 					sizeof (struct k_itimer), 0, SLAB_PANIC,
diff --git a/kernel/power/console.c b/kernel/power/console.c
index a3961b205de..5187136fe1d 100644
--- a/kernel/power/console.c
+++ b/kernel/power/console.c
@@ -14,56 +14,13 @@
 #define SUSPEND_CONSOLE	(MAX_NR_CONSOLES-1)
 
 static int orig_fgconsole, orig_kmsg;
-static int disable_vt_switch;
-
-/*
- * Normally during a suspend, we allocate a new console and switch to it.
- * When we resume, we switch back to the original console.  This switch
- * can be slow, so on systems where the framebuffer can handle restoration
- * of video registers anyways, there's little point in doing the console
- * switch.  This function allows you to disable it by passing it '0'.
- */
-void pm_set_vt_switch(int do_switch)
-{
-	acquire_console_sem();
-	disable_vt_switch = !do_switch;
-	release_console_sem();
-}
-EXPORT_SYMBOL(pm_set_vt_switch);
 
 int pm_prepare_console(void)
 {
-	acquire_console_sem();
-
-	if (disable_vt_switch) {
-		release_console_sem();
-		return 0;
-	}
-
-	orig_fgconsole = fg_console;
-
-	if (vc_allocate(SUSPEND_CONSOLE)) {
-	  /* we can't have a free VC for now. Too bad,
-	   * we don't want to mess the screen for now. */
-		release_console_sem();
+	orig_fgconsole = vt_move_to_console(SUSPEND_CONSOLE, 1);
+	if (orig_fgconsole < 0)
 		return 1;
-	}
 
-	if (set_console(SUSPEND_CONSOLE)) {
-		/*
-		 * We're unable to switch to the SUSPEND_CONSOLE.
-		 * Let the calling function know so it can decide
-		 * what to do.
-		 */
-		release_console_sem();
-		return 1;
-	}
-	release_console_sem();
-
-	if (vt_waitactive(SUSPEND_CONSOLE)) {
-		pr_debug("Suspend: Can't switch VCs.");
-		return 1;
-	}
 	orig_kmsg = kmsg_redirect;
 	kmsg_redirect = SUSPEND_CONSOLE;
 	return 0;
@@ -71,19 +28,9 @@ int pm_prepare_console(void)
 
 void pm_restore_console(void)
 {
-	acquire_console_sem();
-	if (disable_vt_switch) {
-		release_console_sem();
-		return;
-	}
-	set_console(orig_fgconsole);
-	release_console_sem();
-
-	if (vt_waitactive(orig_fgconsole)) {
-		pr_debug("Resume: Can't switch VCs.");
-		return;
+	if (orig_fgconsole >= 0) {
+		vt_move_to_console(orig_fgconsole, 0);
+		kmsg_redirect = orig_kmsg;
 	}
-
-	kmsg_redirect = orig_kmsg;
 }
 #endif
diff --git a/kernel/power/process.c b/kernel/power/process.c
index da2072d7381..cc2e55373b6 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -9,6 +9,7 @@
 #undef DEBUG
 
 #include <linux/interrupt.h>
+#include <linux/oom.h>
 #include <linux/suspend.h>
 #include <linux/module.h>
 #include <linux/syscalls.h>
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index 97955b0e44f..36cb168e433 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -619,7 +619,7 @@ __register_nosave_region(unsigned long start_pfn, unsigned long end_pfn,
 		BUG_ON(!region);
 	} else
 		/* This allocation cannot fail */
-		region = alloc_bootmem_low(sizeof(struct nosave_region));
+		region = alloc_bootmem(sizeof(struct nosave_region));
 	region->start_pfn = start_pfn;
 	region->end_pfn = end_pfn;
 	list_add_tail(&region->list, &nosave_regions);
diff --git a/kernel/power/suspend_test.c b/kernel/power/suspend_test.c
index 17d8bb1acf9..25596e450ac 100644
--- a/kernel/power/suspend_test.c
+++ b/kernel/power/suspend_test.c
@@ -19,7 +19,7 @@
  * The time it takes is system-specific though, so when we test this
  * during system bootup we allow a LOT of time.
  */
-#define TEST_SUSPEND_SECONDS	5
+#define TEST_SUSPEND_SECONDS	10
 
 static unsigned long suspend_test_start_time;
 
@@ -49,7 +49,8 @@ void suspend_test_finish(const char *label)
 	 * has some performance issues.  The stack dump of a WARN_ON
 	 * is more likely to get the right attention than a printk...
 	 */
-	WARN(msec > (TEST_SUSPEND_SECONDS * 1000), "Component: %s\n", label);
+	WARN(msec > (TEST_SUSPEND_SECONDS * 1000),
+	     "Component: %s, time: %u\n", label, msec);
 }
 
 /*
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index 8ba052c86d4..b101cdc4df3 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -13,7 +13,6 @@
 
 #include <linux/module.h>
 #include <linux/file.h>
-#include <linux/utsname.h>
 #include <linux/delay.h>
 #include <linux/bitops.h>
 #include <linux/genhd.h>
diff --git a/kernel/printk.c b/kernel/printk.c
index 602033acd6c..f38b07f78a4 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -206,12 +206,11 @@ __setup("log_buf_len=", log_buf_len_setup);
 #ifdef CONFIG_BOOT_PRINTK_DELAY
 
 static unsigned int boot_delay; /* msecs delay after each printk during bootup */
-static unsigned long long printk_delay_msec; /* per msec, based on boot_delay */
+static unsigned long long loops_per_msec;	/* based on boot_delay */
 
 static int __init boot_delay_setup(char *str)
 {
 	unsigned long lpj;
-	unsigned long long loops_per_msec;
 
 	lpj = preset_lpj ? preset_lpj : 1000000;	/* some guess */
 	loops_per_msec = (unsigned long long)lpj / 1000 * HZ;
@@ -220,10 +219,9 @@ static int __init boot_delay_setup(char *str)
 	if (boot_delay > 10 * 1000)
 		boot_delay = 0;
 
-	printk_delay_msec = loops_per_msec;
-	printk(KERN_DEBUG "boot_delay: %u, preset_lpj: %ld, lpj: %lu, "
-		"HZ: %d, printk_delay_msec: %llu\n",
-		boot_delay, preset_lpj, lpj, HZ, printk_delay_msec);
+	pr_debug("boot_delay: %u, preset_lpj: %ld, lpj: %lu, "
+		"HZ: %d, loops_per_msec: %llu\n",
+		boot_delay, preset_lpj, lpj, HZ, loops_per_msec);
 	return 1;
 }
 __setup("boot_delay=", boot_delay_setup);
@@ -236,7 +234,7 @@ static void boot_delay_msec(void)
 	if (boot_delay == 0 || system_state != SYSTEM_BOOTING)
 		return;
 
-	k = (unsigned long long)printk_delay_msec * boot_delay;
+	k = (unsigned long long)loops_per_msec * boot_delay;
 
 	timeout = jiffies + msecs_to_jiffies(boot_delay);
 	while (k) {
@@ -655,6 +653,20 @@ static int recursion_bug;
 static int new_text_line = 1;
 static char printk_buf[1024];
 
+int printk_delay_msec __read_mostly;
+
+static inline void printk_delay(void)
+{
+	if (unlikely(printk_delay_msec)) {
+		int m = printk_delay_msec;
+
+		while (m--) {
+			mdelay(1);
+			touch_nmi_watchdog();
+		}
+	}
+}
+
 asmlinkage int vprintk(const char *fmt, va_list args)
 {
 	int printed_len = 0;
@@ -664,6 +676,7 @@ asmlinkage int vprintk(const char *fmt, va_list args)
 	char *p;
 
 	boot_delay_msec();
+	printk_delay();
 
 	preempt_disable();
 	/* This stops the holder of console_sem just where we want him */
diff --git a/kernel/profile.c b/kernel/profile.c
index 419250ebec4..a55d3a367ae 100644
--- a/kernel/profile.c
+++ b/kernel/profile.c
@@ -442,48 +442,51 @@ void profile_tick(int type)
 
 #ifdef CONFIG_PROC_FS
 #include <linux/proc_fs.h>
+#include <linux/seq_file.h>
 #include <asm/uaccess.h>
 
-static int prof_cpu_mask_read_proc(char *page, char **start, off_t off,
-			int count, int *eof, void *data)
+static int prof_cpu_mask_proc_show(struct seq_file *m, void *v)
 {
-	int len = cpumask_scnprintf(page, count, data);
-	if (count - len < 2)
-		return -EINVAL;
-	len += sprintf(page + len, "\n");
-	return len;
+	seq_cpumask(m, prof_cpu_mask);
+	seq_putc(m, '\n');
+	return 0;
 }
 
-static int prof_cpu_mask_write_proc(struct file *file,
-	const char __user *buffer,  unsigned long count, void *data)
+static int prof_cpu_mask_proc_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, prof_cpu_mask_proc_show, NULL);
+}
+
+static ssize_t prof_cpu_mask_proc_write(struct file *file,
+	const char __user *buffer, size_t count, loff_t *pos)
 {
-	struct cpumask *mask = data;
-	unsigned long full_count = count, err;
 	cpumask_var_t new_value;
+	int err;
 
 	if (!alloc_cpumask_var(&new_value, GFP_KERNEL))
 		return -ENOMEM;
 
 	err = cpumask_parse_user(buffer, count, new_value);
 	if (!err) {
-		cpumask_copy(mask, new_value);
-		err = full_count;
+		cpumask_copy(prof_cpu_mask, new_value);
+		err = count;
 	}
 	free_cpumask_var(new_value);
 	return err;
 }
 
+static const struct file_operations prof_cpu_mask_proc_fops = {
+	.open		= prof_cpu_mask_proc_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+	.write		= prof_cpu_mask_proc_write,
+};
+
 void create_prof_cpu_mask(struct proc_dir_entry *root_irq_dir)
 {
-	struct proc_dir_entry *entry;
-
 	/* create /proc/irq/prof_cpu_mask */
-	entry = create_proc_entry("prof_cpu_mask", 0600, root_irq_dir);
-	if (!entry)
-		return;
-	entry->data = prof_cpu_mask;
-	entry->read_proc = prof_cpu_mask_read_proc;
-	entry->write_proc = prof_cpu_mask_write_proc;
+	proc_create("prof_cpu_mask", 0600, root_irq_dir, &prof_cpu_mask_proc_fops);
 }
 
 /*
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 307c285af59..23bd09cd042 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -266,9 +266,10 @@ static int ignoring_children(struct sighand_struct *sigh)
  * or self-reaping.  Do notification now if it would have happened earlier.
  * If it should reap itself, return true.
  *
- * If it's our own child, there is no notification to do.
- * But if our normal children self-reap, then this child
- * was prevented by ptrace and we must reap it now.
+ * If it's our own child, there is no notification to do. But if our normal
+ * children self-reap, then this child was prevented by ptrace and we must
+ * reap it now, in that case we must also wake up sub-threads sleeping in
+ * do_wait().
  */
 static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
 {
@@ -278,8 +279,10 @@ static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
 		if (!task_detached(p) && thread_group_empty(p)) {
 			if (!same_thread_group(p->real_parent, tracer))
 				do_notify_parent(p, p->exit_signal);
-			else if (ignoring_children(tracer->sighand))
+			else if (ignoring_children(tracer->sighand)) {
+				__wake_up_parent(p, tracer);
 				p->exit_signal = -1;
+			}
 		}
 		if (task_detached(p)) {
 			/* Mark it as in the process of being reaped. */
diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
index bd5d5c8e514..400183346ad 100644
--- a/kernel/rcupdate.c
+++ b/kernel/rcupdate.c
@@ -19,7 +19,7 @@
  *
  * Authors: Dipankar Sarma <dipankar@in.ibm.com>
  *	    Manfred Spraul <manfred@colorfullife.com>
- * 
+ *
  * Based on the original work by Paul McKenney <paulmck@us.ibm.com>
  * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen.
  * Papers:
@@ -27,7 +27,7 @@
  * http://lse.sourceforge.net/locking/rclock_OLS.2001.05.01c.sc.pdf (OLS2001)
  *
  * For detailed explanation of Read-Copy Update mechanism see -
- * 		http://lse.sourceforge.net/locking/rcupdate.html
+ *		http://lse.sourceforge.net/locking/rcupdate.html
  *
  */
 #include <linux/types.h>
@@ -46,22 +46,15 @@
 #include <linux/module.h>
 #include <linux/kernel_stat.h>
 
-enum rcu_barrier {
-	RCU_BARRIER_STD,
-	RCU_BARRIER_BH,
-	RCU_BARRIER_SCHED,
-};
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+static struct lock_class_key rcu_lock_key;
+struct lockdep_map rcu_lock_map =
+	STATIC_LOCKDEP_MAP_INIT("rcu_read_lock", &rcu_lock_key);
+EXPORT_SYMBOL_GPL(rcu_lock_map);
+#endif
 
-static DEFINE_PER_CPU(struct rcu_head, rcu_barrier_head) = {NULL};
-static atomic_t rcu_barrier_cpu_count;
-static DEFINE_MUTEX(rcu_barrier_mutex);
-static struct completion rcu_barrier_completion;
 int rcu_scheduler_active __read_mostly;
 
-static atomic_t rcu_migrate_type_count = ATOMIC_INIT(0);
-static struct rcu_head rcu_migrate_head[3];
-static DECLARE_WAIT_QUEUE_HEAD(rcu_migrate_wq);
-
 /*
  * Awaken the corresponding synchronize_rcu() instance now that a
  * grace period has elapsed.
@@ -74,6 +67,8 @@ void wakeme_after_rcu(struct rcu_head  *head)
 	complete(&rcu->completion);
 }
 
+#ifdef CONFIG_TREE_PREEMPT_RCU
+
 /**
  * synchronize_rcu - wait until a grace period has elapsed.
  *
@@ -87,7 +82,7 @@ void synchronize_rcu(void)
 {
 	struct rcu_synchronize rcu;
 
-	if (rcu_blocking_is_gp())
+	if (!rcu_scheduler_active)
 		return;
 
 	init_completion(&rcu.completion);
@@ -98,6 +93,46 @@ void synchronize_rcu(void)
 }
 EXPORT_SYMBOL_GPL(synchronize_rcu);
 
+#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
+
+/**
+ * synchronize_sched - wait until an rcu-sched grace period has elapsed.
+ *
+ * Control will return to the caller some time after a full rcu-sched
+ * grace period has elapsed, in other words after all currently executing
+ * rcu-sched read-side critical sections have completed.   These read-side
+ * critical sections are delimited by rcu_read_lock_sched() and
+ * rcu_read_unlock_sched(), and may be nested.  Note that preempt_disable(),
+ * local_irq_disable(), and so on may be used in place of
+ * rcu_read_lock_sched().
+ *
+ * This means that all preempt_disable code sequences, including NMI and
+ * hardware-interrupt handlers, in progress on entry will have completed
+ * before this primitive returns.  However, this does not guarantee that
+ * softirq handlers will have completed, since in some kernels, these
+ * handlers can run in process context, and can block.
+ *
+ * This primitive provides the guarantees made by the (now removed)
+ * synchronize_kernel() API.  In contrast, synchronize_rcu() only
+ * guarantees that rcu_read_lock() sections will have completed.
+ * In "classic RCU", these two guarantees happen to be one and
+ * the same, but can differ in realtime RCU implementations.
+ */
+void synchronize_sched(void)
+{
+	struct rcu_synchronize rcu;
+
+	if (rcu_blocking_is_gp())
+		return;
+
+	init_completion(&rcu.completion);
+	/* Will wake me after RCU finished. */
+	call_rcu_sched(&rcu.head, wakeme_after_rcu);
+	/* Wait for it. */
+	wait_for_completion(&rcu.completion);
+}
+EXPORT_SYMBOL_GPL(synchronize_sched);
+
 /**
  * synchronize_rcu_bh - wait until an rcu_bh grace period has elapsed.
  *
@@ -122,129 +157,10 @@ void synchronize_rcu_bh(void)
 }
 EXPORT_SYMBOL_GPL(synchronize_rcu_bh);
 
-static void rcu_barrier_callback(struct rcu_head *notused)
-{
-	if (atomic_dec_and_test(&rcu_barrier_cpu_count))
-		complete(&rcu_barrier_completion);
-}
-
-/*
- * Called with preemption disabled, and from cross-cpu IRQ context.
- */
-static void rcu_barrier_func(void *type)
-{
-	int cpu = smp_processor_id();
-	struct rcu_head *head = &per_cpu(rcu_barrier_head, cpu);
-
-	atomic_inc(&rcu_barrier_cpu_count);
-	switch ((enum rcu_barrier)type) {
-	case RCU_BARRIER_STD:
-		call_rcu(head, rcu_barrier_callback);
-		break;
-	case RCU_BARRIER_BH:
-		call_rcu_bh(head, rcu_barrier_callback);
-		break;
-	case RCU_BARRIER_SCHED:
-		call_rcu_sched(head, rcu_barrier_callback);
-		break;
-	}
-}
-
-static inline void wait_migrated_callbacks(void)
-{
-	wait_event(rcu_migrate_wq, !atomic_read(&rcu_migrate_type_count));
-	smp_mb(); /* In case we didn't sleep. */
-}
-
-/*
- * Orchestrate the specified type of RCU barrier, waiting for all
- * RCU callbacks of the specified type to complete.
- */
-static void _rcu_barrier(enum rcu_barrier type)
-{
-	BUG_ON(in_interrupt());
-	/* Take cpucontrol mutex to protect against CPU hotplug */
-	mutex_lock(&rcu_barrier_mutex);
-	init_completion(&rcu_barrier_completion);
-	/*
-	 * Initialize rcu_barrier_cpu_count to 1, then invoke
-	 * rcu_barrier_func() on each CPU, so that each CPU also has
-	 * incremented rcu_barrier_cpu_count.  Only then is it safe to
-	 * decrement rcu_barrier_cpu_count -- otherwise the first CPU
-	 * might complete its grace period before all of the other CPUs
-	 * did their increment, causing this function to return too
-	 * early.
-	 */
-	atomic_set(&rcu_barrier_cpu_count, 1);
-	on_each_cpu(rcu_barrier_func, (void *)type, 1);
-	if (atomic_dec_and_test(&rcu_barrier_cpu_count))
-		complete(&rcu_barrier_completion);
-	wait_for_completion(&rcu_barrier_completion);
-	mutex_unlock(&rcu_barrier_mutex);
-	wait_migrated_callbacks();
-}
-
-/**
- * rcu_barrier - Wait until all in-flight call_rcu() callbacks complete.
- */
-void rcu_barrier(void)
-{
-	_rcu_barrier(RCU_BARRIER_STD);
-}
-EXPORT_SYMBOL_GPL(rcu_barrier);
-
-/**
- * rcu_barrier_bh - Wait until all in-flight call_rcu_bh() callbacks complete.
- */
-void rcu_barrier_bh(void)
-{
-	_rcu_barrier(RCU_BARRIER_BH);
-}
-EXPORT_SYMBOL_GPL(rcu_barrier_bh);
-
-/**
- * rcu_barrier_sched - Wait for in-flight call_rcu_sched() callbacks.
- */
-void rcu_barrier_sched(void)
-{
-	_rcu_barrier(RCU_BARRIER_SCHED);
-}
-EXPORT_SYMBOL_GPL(rcu_barrier_sched);
-
-static void rcu_migrate_callback(struct rcu_head *notused)
-{
-	if (atomic_dec_and_test(&rcu_migrate_type_count))
-		wake_up(&rcu_migrate_wq);
-}
-
-extern int rcu_cpu_notify(struct notifier_block *self,
-			  unsigned long action, void *hcpu);
-
 static int __cpuinit rcu_barrier_cpu_hotplug(struct notifier_block *self,
 		unsigned long action, void *hcpu)
 {
-	rcu_cpu_notify(self, action, hcpu);
-	if (action == CPU_DYING) {
-		/*
-		 * preempt_disable() in on_each_cpu() prevents stop_machine(),
-		 * so when "on_each_cpu(rcu_barrier_func, (void *)type, 1);"
-		 * returns, all online cpus have queued rcu_barrier_func(),
-		 * and the dead cpu(if it exist) queues rcu_migrate_callback()s.
-		 *
-		 * These callbacks ensure _rcu_barrier() waits for all
-		 * RCU callbacks of the specified type to complete.
-		 */
-		atomic_set(&rcu_migrate_type_count, 3);
-		call_rcu_bh(rcu_migrate_head, rcu_migrate_callback);
-		call_rcu_sched(rcu_migrate_head + 1, rcu_migrate_callback);
-		call_rcu(rcu_migrate_head + 2, rcu_migrate_callback);
-	} else if (action == CPU_DOWN_PREPARE) {
-		/* Don't need to wait until next removal operation. */
-		/* rcu_migrate_head is protected by cpu_add_remove_lock */
-		wait_migrated_callbacks();
-	}
-
-	return NOTIFY_OK;
+	return rcu_cpu_notify(self, action, hcpu);
 }
 
 void __init rcu_init(void)
diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index b33db539a8a..697c0a0229d 100644
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -18,7 +18,7 @@
  * Copyright (C) IBM Corporation, 2005, 2006
  *
  * Authors: Paul E. McKenney <paulmck@us.ibm.com>
- *          Josh Triplett <josh@freedesktop.org>
+ *	  Josh Triplett <josh@freedesktop.org>
  *
  * See also:  Documentation/RCU/torture.txt
  */
@@ -50,7 +50,7 @@
 
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com> and "
-              "Josh Triplett <josh@freedesktop.org>");
+	      "Josh Triplett <josh@freedesktop.org>");
 
 static int nreaders = -1;	/* # reader threads, defaults to 2*ncpus */
 static int nfakewriters = 4;	/* # fake writer threads */
@@ -110,8 +110,8 @@ struct rcu_torture {
 };
 
 static LIST_HEAD(rcu_torture_freelist);
-static struct rcu_torture *rcu_torture_current = NULL;
-static long rcu_torture_current_version = 0;
+static struct rcu_torture *rcu_torture_current;
+static long rcu_torture_current_version;
 static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN];
 static DEFINE_SPINLOCK(rcu_torture_lock);
 static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count) =
@@ -124,11 +124,11 @@ static atomic_t n_rcu_torture_alloc_fail;
 static atomic_t n_rcu_torture_free;
 static atomic_t n_rcu_torture_mberror;
 static atomic_t n_rcu_torture_error;
-static long n_rcu_torture_timers = 0;
+static long n_rcu_torture_timers;
 static struct list_head rcu_torture_removed;
 static cpumask_var_t shuffle_tmp_mask;
 
-static int stutter_pause_test = 0;
+static int stutter_pause_test;
 
 #if defined(MODULE) || defined(CONFIG_RCU_TORTURE_TEST_RUNNABLE)
 #define RCUTORTURE_RUNNABLE_INIT 1
@@ -267,7 +267,8 @@ struct rcu_torture_ops {
 	int irq_capable;
 	char *name;
 };
-static struct rcu_torture_ops *cur_ops = NULL;
+
+static struct rcu_torture_ops *cur_ops;
 
 /*
  * Definitions for rcu torture testing.
@@ -281,14 +282,17 @@ static int rcu_torture_read_lock(void) __acquires(RCU)
 
 static void rcu_read_delay(struct rcu_random_state *rrsp)
 {
-	long delay;
-	const long longdelay = 200;
+	const unsigned long shortdelay_us = 200;
+	const unsigned long longdelay_ms = 50;
 
-	/* We want there to be long-running readers, but not all the time. */
+	/* We want a short delay sometimes to make a reader delay the grace
+	 * period, and we want a long delay occasionally to trigger
+	 * force_quiescent_state. */
 
-	delay = rcu_random(rrsp) % (nrealreaders * 2 * longdelay);
-	if (!delay)
-		udelay(longdelay);
+	if (!(rcu_random(rrsp) % (nrealreaders * 2000 * longdelay_ms)))
+		mdelay(longdelay_ms);
+	if (!(rcu_random(rrsp) % (nrealreaders * 2 * shortdelay_us)))
+		udelay(shortdelay_us);
 }
 
 static void rcu_torture_read_unlock(int idx) __releases(RCU)
@@ -339,8 +343,8 @@ static struct rcu_torture_ops rcu_ops = {
 	.sync		= synchronize_rcu,
 	.cb_barrier	= rcu_barrier,
 	.stats		= NULL,
-	.irq_capable 	= 1,
-	.name 		= "rcu"
+	.irq_capable	= 1,
+	.name		= "rcu"
 };
 
 static void rcu_sync_torture_deferred_free(struct rcu_torture *p)
@@ -602,8 +606,6 @@ static struct rcu_torture_ops sched_ops_sync = {
 	.name		= "sched_sync"
 };
 
-extern int rcu_expedited_torture_stats(char *page);
-
 static struct rcu_torture_ops sched_expedited_ops = {
 	.init		= rcu_sync_torture_init,
 	.cleanup	= NULL,
@@ -638,14 +640,15 @@ rcu_torture_writer(void *arg)
 
 	do {
 		schedule_timeout_uninterruptible(1);
-		if ((rp = rcu_torture_alloc()) == NULL)
+		rp = rcu_torture_alloc();
+		if (rp == NULL)
 			continue;
 		rp->rtort_pipe_count = 0;
 		udelay(rcu_random(&rand) & 0x3ff);
 		old_rp = rcu_torture_current;
 		rp->rtort_mbtest = 1;
 		rcu_assign_pointer(rcu_torture_current, rp);
-		smp_wmb();
+		smp_wmb(); /* Mods to old_rp must follow rcu_assign_pointer() */
 		if (old_rp) {
 			i = old_rp->rtort_pipe_count;
 			if (i > RCU_TORTURE_PIPE_LEN)
@@ -1110,7 +1113,7 @@ rcu_torture_init(void)
 		printk(KERN_ALERT "rcutorture: invalid torture type: \"%s\"\n",
 		       torture_type);
 		mutex_unlock(&fullstop_mutex);
-		return (-EINVAL);
+		return -EINVAL;
 	}
 	if (cur_ops->init)
 		cur_ops->init(); /* no "goto unwind" prior to this point!!! */
@@ -1161,7 +1164,7 @@ rcu_torture_init(void)
 		goto unwind;
 	}
 	fakewriter_tasks = kzalloc(nfakewriters * sizeof(fakewriter_tasks[0]),
-	                           GFP_KERNEL);
+				   GFP_KERNEL);
 	if (fakewriter_tasks == NULL) {
 		VERBOSE_PRINTK_ERRSTRING("out of memory");
 		firsterr = -ENOMEM;
@@ -1170,7 +1173,7 @@ rcu_torture_init(void)
 	for (i = 0; i < nfakewriters; i++) {
 		VERBOSE_PRINTK_STRING("Creating rcu_torture_fakewriter task");
 		fakewriter_tasks[i] = kthread_run(rcu_torture_fakewriter, NULL,
-		                                  "rcu_torture_fakewriter");
+						  "rcu_torture_fakewriter");
 		if (IS_ERR(fakewriter_tasks[i])) {
 			firsterr = PTR_ERR(fakewriter_tasks[i]);
 			VERBOSE_PRINTK_ERRSTRING("Failed to create fakewriter");
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 6b11b07cfe7..705f02ac743 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -25,7 +25,7 @@
  * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen.
  *
  * For detailed explanation of Read-Copy Update mechanism see -
- * 	Documentation/RCU
+ *	Documentation/RCU
  */
 #include <linux/types.h>
 #include <linux/kernel.h>
@@ -49,13 +49,6 @@
 
 #include "rcutree.h"
 
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-static struct lock_class_key rcu_lock_key;
-struct lockdep_map rcu_lock_map =
-	STATIC_LOCKDEP_MAP_INIT("rcu_read_lock", &rcu_lock_key);
-EXPORT_SYMBOL_GPL(rcu_lock_map);
-#endif
-
 /* Data structures. */
 
 #define RCU_STATE_INITIALIZER(name) { \
@@ -70,6 +63,9 @@ EXPORT_SYMBOL_GPL(rcu_lock_map);
 	.gpnum = -300, \
 	.completed = -300, \
 	.onofflock = __SPIN_LOCK_UNLOCKED(&name.onofflock), \
+	.orphan_cbs_list = NULL, \
+	.orphan_cbs_tail = &name.orphan_cbs_list, \
+	.orphan_qlen = 0, \
 	.fqslock = __SPIN_LOCK_UNLOCKED(&name.fqslock), \
 	.n_force_qs = 0, \
 	.n_force_qs_ngp = 0, \
@@ -81,24 +77,16 @@ DEFINE_PER_CPU(struct rcu_data, rcu_sched_data);
 struct rcu_state rcu_bh_state = RCU_STATE_INITIALIZER(rcu_bh_state);
 DEFINE_PER_CPU(struct rcu_data, rcu_bh_data);
 
-extern long rcu_batches_completed_sched(void);
-static struct rcu_node *rcu_get_root(struct rcu_state *rsp);
-static void cpu_quiet_msk(unsigned long mask, struct rcu_state *rsp,
-			  struct rcu_node *rnp, unsigned long flags);
-static void cpu_quiet_msk_finish(struct rcu_state *rsp, unsigned long flags);
-#ifdef CONFIG_HOTPLUG_CPU
-static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp);
-#endif /* #ifdef CONFIG_HOTPLUG_CPU */
-static void __rcu_process_callbacks(struct rcu_state *rsp,
-				    struct rcu_data *rdp);
-static void __call_rcu(struct rcu_head *head,
-		       void (*func)(struct rcu_head *rcu),
-		       struct rcu_state *rsp);
-static int __rcu_pending(struct rcu_state *rsp, struct rcu_data *rdp);
-static void __cpuinit rcu_init_percpu_data(int cpu, struct rcu_state *rsp,
-					   int preemptable);
 
-#include "rcutree_plugin.h"
+/*
+ * Return true if an RCU grace period is in progress.  The ACCESS_ONCE()s
+ * permit this function to be invoked without holding the root rcu_node
+ * structure's ->lock, but of course results can be subject to change.
+ */
+static int rcu_gp_in_progress(struct rcu_state *rsp)
+{
+	return ACCESS_ONCE(rsp->completed) != ACCESS_ONCE(rsp->gpnum);
+}
 
 /*
  * Note a quiescent state.  Because we do not need to know
@@ -107,27 +95,23 @@ static void __cpuinit rcu_init_percpu_data(int cpu, struct rcu_state *rsp,
  */
 void rcu_sched_qs(int cpu)
 {
-	unsigned long flags;
 	struct rcu_data *rdp;
 
-	local_irq_save(flags);
 	rdp = &per_cpu(rcu_sched_data, cpu);
-	rdp->passed_quiesc = 1;
 	rdp->passed_quiesc_completed = rdp->completed;
-	rcu_preempt_qs(cpu);
-	local_irq_restore(flags);
+	barrier();
+	rdp->passed_quiesc = 1;
+	rcu_preempt_note_context_switch(cpu);
 }
 
 void rcu_bh_qs(int cpu)
 {
-	unsigned long flags;
 	struct rcu_data *rdp;
 
-	local_irq_save(flags);
 	rdp = &per_cpu(rcu_bh_data, cpu);
-	rdp->passed_quiesc = 1;
 	rdp->passed_quiesc_completed = rdp->completed;
-	local_irq_restore(flags);
+	barrier();
+	rdp->passed_quiesc = 1;
 }
 
 #ifdef CONFIG_NO_HZ
@@ -141,6 +125,10 @@ static int blimit = 10;		/* Maximum callbacks per softirq. */
 static int qhimark = 10000;	/* If this many pending, ignore blimit. */
 static int qlowmark = 100;	/* Once only this many pending, use blimit. */
 
+module_param(blimit, int, 0);
+module_param(qhimark, int, 0);
+module_param(qlowmark, int, 0);
+
 static void force_quiescent_state(struct rcu_state *rsp, int relaxed);
 static int rcu_pending(int cpu);
 
@@ -177,9 +165,7 @@ cpu_has_callbacks_ready_to_invoke(struct rcu_data *rdp)
 static int
 cpu_needs_another_gp(struct rcu_state *rsp, struct rcu_data *rdp)
 {
-	/* ACCESS_ONCE() because we are accessing outside of lock. */
-	return *rdp->nxttail[RCU_DONE_TAIL] &&
-	       ACCESS_ONCE(rsp->completed) == ACCESS_ONCE(rsp->gpnum);
+	return *rdp->nxttail[RCU_DONE_TAIL] && !rcu_gp_in_progress(rsp);
 }
 
 /*
@@ -373,7 +359,7 @@ static long dyntick_recall_completed(struct rcu_state *rsp)
 /*
  * Snapshot the specified CPU's dynticks counter so that we can later
  * credit them with an implicit quiescent state.  Return 1 if this CPU
- * is already in a quiescent state courtesy of dynticks idle mode.
+ * is in dynticks idle mode, which is an extended quiescent state.
  */
 static int dyntick_save_progress_counter(struct rcu_data *rdp)
 {
@@ -479,30 +465,34 @@ static void print_other_cpu_stall(struct rcu_state *rsp)
 	long delta;
 	unsigned long flags;
 	struct rcu_node *rnp = rcu_get_root(rsp);
-	struct rcu_node *rnp_cur = rsp->level[NUM_RCU_LVLS - 1];
-	struct rcu_node *rnp_end = &rsp->node[NUM_RCU_NODES];
 
 	/* Only let one CPU complain about others per time interval. */
 
 	spin_lock_irqsave(&rnp->lock, flags);
 	delta = jiffies - rsp->jiffies_stall;
-	if (delta < RCU_STALL_RAT_DELAY || rsp->gpnum == rsp->completed) {
+	if (delta < RCU_STALL_RAT_DELAY || !rcu_gp_in_progress(rsp)) {
 		spin_unlock_irqrestore(&rnp->lock, flags);
 		return;
 	}
 	rsp->jiffies_stall = jiffies + RCU_SECONDS_TILL_STALL_RECHECK;
+
+	/*
+	 * Now rat on any tasks that got kicked up to the root rcu_node
+	 * due to CPU offlining.
+	 */
+	rcu_print_task_stall(rnp);
 	spin_unlock_irqrestore(&rnp->lock, flags);
 
 	/* OK, time to rat on our buddy... */
 
 	printk(KERN_ERR "INFO: RCU detected CPU stalls:");
-	for (; rnp_cur < rnp_end; rnp_cur++) {
+	rcu_for_each_leaf_node(rsp, rnp) {
 		rcu_print_task_stall(rnp);
-		if (rnp_cur->qsmask == 0)
+		if (rnp->qsmask == 0)
 			continue;
-		for (cpu = 0; cpu <= rnp_cur->grphi - rnp_cur->grplo; cpu++)
-			if (rnp_cur->qsmask & (1UL << cpu))
-				printk(" %d", rnp_cur->grplo + cpu);
+		for (cpu = 0; cpu <= rnp->grphi - rnp->grplo; cpu++)
+			if (rnp->qsmask & (1UL << cpu))
+				printk(" %d", rnp->grplo + cpu);
 	}
 	printk(" (detected by %d, t=%ld jiffies)\n",
 	       smp_processor_id(), (long)(jiffies - rsp->gp_start));
@@ -541,8 +531,7 @@ static void check_cpu_stall(struct rcu_state *rsp, struct rcu_data *rdp)
 		/* We haven't checked in, so go dump stack. */
 		print_cpu_stall(rsp);
 
-	} else if (rsp->gpnum != rsp->completed &&
-		   delta >= RCU_STALL_RAT_DELAY) {
+	} else if (rcu_gp_in_progress(rsp) && delta >= RCU_STALL_RAT_DELAY) {
 
 		/* They had two time units to dump stack, so complain. */
 		print_other_cpu_stall(rsp);
@@ -605,8 +594,6 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags)
 {
 	struct rcu_data *rdp = rsp->rda[smp_processor_id()];
 	struct rcu_node *rnp = rcu_get_root(rsp);
-	struct rcu_node *rnp_cur;
-	struct rcu_node *rnp_end;
 
 	if (!cpu_needs_another_gp(rsp, rdp)) {
 		spin_unlock_irqrestore(&rnp->lock, flags);
@@ -615,6 +602,7 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags)
 
 	/* Advance to a new grace period and initialize state. */
 	rsp->gpnum++;
+	WARN_ON_ONCE(rsp->signaled == RCU_GP_INIT);
 	rsp->signaled = RCU_GP_INIT; /* Hold off force_quiescent_state. */
 	rsp->jiffies_force_qs = jiffies + RCU_JIFFIES_TILL_FORCE_QS;
 	record_gp_stall_check_time(rsp);
@@ -622,16 +610,24 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags)
 	note_new_gpnum(rsp, rdp);
 
 	/*
-	 * Because we are first, we know that all our callbacks will
-	 * be covered by this upcoming grace period, even the ones
-	 * that were registered arbitrarily recently.
+	 * Because this CPU just now started the new grace period, we know
+	 * that all of its callbacks will be covered by this upcoming grace
+	 * period, even the ones that were registered arbitrarily recently.
+	 * Therefore, advance all outstanding callbacks to RCU_WAIT_TAIL.
+	 *
+	 * Other CPUs cannot be sure exactly when the grace period started.
+	 * Therefore, their recently registered callbacks must pass through
+	 * an additional RCU_NEXT_READY stage, so that they will be handled
+	 * by the next RCU grace period.
 	 */
 	rdp->nxttail[RCU_NEXT_READY_TAIL] = rdp->nxttail[RCU_NEXT_TAIL];
 	rdp->nxttail[RCU_WAIT_TAIL] = rdp->nxttail[RCU_NEXT_TAIL];
 
 	/* Special-case the common single-level case. */
 	if (NUM_RCU_NODES == 1) {
+		rcu_preempt_check_blocked_tasks(rnp);
 		rnp->qsmask = rnp->qsmaskinit;
+		rnp->gpnum = rsp->gpnum;
 		rsp->signaled = RCU_SIGNAL_INIT; /* force_quiescent_state OK. */
 		spin_unlock_irqrestore(&rnp->lock, flags);
 		return;
@@ -644,42 +640,28 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags)
 	spin_lock(&rsp->onofflock);  /* irqs already disabled. */
 
 	/*
-	 * Set the quiescent-state-needed bits in all the non-leaf RCU
-	 * nodes for all currently online CPUs.  This operation relies
-	 * on the layout of the hierarchy within the rsp->node[] array.
-	 * Note that other CPUs will access only the leaves of the
-	 * hierarchy, which still indicate that no grace period is in
-	 * progress.  In addition, we have excluded CPU-hotplug operations.
-	 *
-	 * We therefore do not need to hold any locks.  Any required
-	 * memory barriers will be supplied by the locks guarding the
-	 * leaf rcu_nodes in the hierarchy.
-	 */
-
-	rnp_end = rsp->level[NUM_RCU_LVLS - 1];
-	for (rnp_cur = &rsp->node[0]; rnp_cur < rnp_end; rnp_cur++)
-		rnp_cur->qsmask = rnp_cur->qsmaskinit;
-
-	/*
-	 * Now set up the leaf nodes.  Here we must be careful.  First,
-	 * we need to hold the lock in order to exclude other CPUs, which
-	 * might be contending for the leaf nodes' locks.  Second, as
-	 * soon as we initialize a given leaf node, its CPUs might run
-	 * up the rest of the hierarchy.  We must therefore acquire locks
-	 * for each node that we touch during this stage.  (But we still
-	 * are excluding CPU-hotplug operations.)
+	 * Set the quiescent-state-needed bits in all the rcu_node
+	 * structures for all currently online CPUs in breadth-first
+	 * order, starting from the root rcu_node structure.  This
+	 * operation relies on the layout of the hierarchy within the
+	 * rsp->node[] array.  Note that other CPUs will access only
+	 * the leaves of the hierarchy, which still indicate that no
+	 * grace period is in progress, at least until the corresponding
+	 * leaf node has been initialized.  In addition, we have excluded
+	 * CPU-hotplug operations.
 	 *
 	 * Note that the grace period cannot complete until we finish
 	 * the initialization process, as there will be at least one
 	 * qsmask bit set in the root node until that time, namely the
-	 * one corresponding to this CPU.
+	 * one corresponding to this CPU, due to the fact that we have
+	 * irqs disabled.
 	 */
-	rnp_end = &rsp->node[NUM_RCU_NODES];
-	rnp_cur = rsp->level[NUM_RCU_LVLS - 1];
-	for (; rnp_cur < rnp_end; rnp_cur++) {
-		spin_lock(&rnp_cur->lock);	/* irqs already disabled. */
-		rnp_cur->qsmask = rnp_cur->qsmaskinit;
-		spin_unlock(&rnp_cur->lock);	/* irqs already disabled. */
+	rcu_for_each_node_breadth_first(rsp, rnp) {
+		spin_lock(&rnp->lock);	/* irqs already disabled. */
+		rcu_preempt_check_blocked_tasks(rnp);
+		rnp->qsmask = rnp->qsmaskinit;
+		rnp->gpnum = rsp->gpnum;
+		spin_unlock(&rnp->lock);	/* irqs already disabled. */
 	}
 
 	rsp->signaled = RCU_SIGNAL_INIT; /* force_quiescent_state now OK. */
@@ -720,8 +702,9 @@ rcu_process_gp_end(struct rcu_state *rsp, struct rcu_data *rdp)
  * hold rnp->lock, as required by rcu_start_gp(), which will release it.
  */
 static void cpu_quiet_msk_finish(struct rcu_state *rsp, unsigned long flags)
-	__releases(rnp->lock)
+	__releases(rcu_get_root(rsp)->lock)
 {
+	WARN_ON_ONCE(!rcu_gp_in_progress(rsp));
 	rsp->completed = rsp->gpnum;
 	rcu_process_gp_end(rsp, rsp->rda[smp_processor_id()]);
 	rcu_start_gp(rsp, flags);  /* releases root node's rnp->lock. */
@@ -739,6 +722,8 @@ cpu_quiet_msk(unsigned long mask, struct rcu_state *rsp, struct rcu_node *rnp,
 	      unsigned long flags)
 	__releases(rnp->lock)
 {
+	struct rcu_node *rnp_c;
+
 	/* Walk up the rcu_node hierarchy. */
 	for (;;) {
 		if (!(rnp->qsmask & mask)) {
@@ -762,8 +747,10 @@ cpu_quiet_msk(unsigned long mask, struct rcu_state *rsp, struct rcu_node *rnp,
 			break;
 		}
 		spin_unlock_irqrestore(&rnp->lock, flags);
+		rnp_c = rnp;
 		rnp = rnp->parent;
 		spin_lock_irqsave(&rnp->lock, flags);
+		WARN_ON_ONCE(rnp_c->qsmask);
 	}
 
 	/*
@@ -776,10 +763,10 @@ cpu_quiet_msk(unsigned long mask, struct rcu_state *rsp, struct rcu_node *rnp,
 
 /*
  * Record a quiescent state for the specified CPU, which must either be
- * the current CPU or an offline CPU.  The lastcomp argument is used to
- * make sure we are still in the grace period of interest.  We don't want
- * to end the current grace period based on quiescent states detected in
- * an earlier grace period!
+ * the current CPU.  The lastcomp argument is used to make sure we are
+ * still in the grace period of interest.  We don't want to end the current
+ * grace period based on quiescent states detected in an earlier grace
+ * period!
  */
 static void
 cpu_quiet(int cpu, struct rcu_state *rsp, struct rcu_data *rdp, long lastcomp)
@@ -814,7 +801,6 @@ cpu_quiet(int cpu, struct rcu_state *rsp, struct rcu_data *rdp, long lastcomp)
 		 * This GP can't end until cpu checks in, so all of our
 		 * callbacks can be processed during the next GP.
 		 */
-		rdp = rsp->rda[smp_processor_id()];
 		rdp->nxttail[RCU_NEXT_READY_TAIL] = rdp->nxttail[RCU_NEXT_TAIL];
 
 		cpu_quiet_msk(mask, rsp, rnp, flags); /* releases rnp->lock */
@@ -855,24 +841,70 @@ rcu_check_quiescent_state(struct rcu_state *rsp, struct rcu_data *rdp)
 #ifdef CONFIG_HOTPLUG_CPU
 
 /*
+ * Move a dying CPU's RCU callbacks to the ->orphan_cbs_list for the
+ * specified flavor of RCU.  The callbacks will be adopted by the next
+ * _rcu_barrier() invocation or by the CPU_DEAD notifier, whichever
+ * comes first.  Because this is invoked from the CPU_DYING notifier,
+ * irqs are already disabled.
+ */
+static void rcu_send_cbs_to_orphanage(struct rcu_state *rsp)
+{
+	int i;
+	struct rcu_data *rdp = rsp->rda[smp_processor_id()];
+
+	if (rdp->nxtlist == NULL)
+		return;  /* irqs disabled, so comparison is stable. */
+	spin_lock(&rsp->onofflock);  /* irqs already disabled. */
+	*rsp->orphan_cbs_tail = rdp->nxtlist;
+	rsp->orphan_cbs_tail = rdp->nxttail[RCU_NEXT_TAIL];
+	rdp->nxtlist = NULL;
+	for (i = 0; i < RCU_NEXT_SIZE; i++)
+		rdp->nxttail[i] = &rdp->nxtlist;
+	rsp->orphan_qlen += rdp->qlen;
+	rdp->qlen = 0;
+	spin_unlock(&rsp->onofflock);  /* irqs remain disabled. */
+}
+
+/*
+ * Adopt previously orphaned RCU callbacks.
+ */
+static void rcu_adopt_orphan_cbs(struct rcu_state *rsp)
+{
+	unsigned long flags;
+	struct rcu_data *rdp;
+
+	spin_lock_irqsave(&rsp->onofflock, flags);
+	rdp = rsp->rda[smp_processor_id()];
+	if (rsp->orphan_cbs_list == NULL) {
+		spin_unlock_irqrestore(&rsp->onofflock, flags);
+		return;
+	}
+	*rdp->nxttail[RCU_NEXT_TAIL] = rsp->orphan_cbs_list;
+	rdp->nxttail[RCU_NEXT_TAIL] = rsp->orphan_cbs_tail;
+	rdp->qlen += rsp->orphan_qlen;
+	rsp->orphan_cbs_list = NULL;
+	rsp->orphan_cbs_tail = &rsp->orphan_cbs_list;
+	rsp->orphan_qlen = 0;
+	spin_unlock_irqrestore(&rsp->onofflock, flags);
+}
+
+/*
  * Remove the outgoing CPU from the bitmasks in the rcu_node hierarchy
  * and move all callbacks from the outgoing CPU to the current one.
  */
 static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp)
 {
-	int i;
 	unsigned long flags;
 	long lastcomp;
 	unsigned long mask;
 	struct rcu_data *rdp = rsp->rda[cpu];
-	struct rcu_data *rdp_me;
 	struct rcu_node *rnp;
 
 	/* Exclude any attempts to start a new grace period. */
 	spin_lock_irqsave(&rsp->onofflock, flags);
 
 	/* Remove the outgoing CPU from the masks in the rcu_node hierarchy. */
-	rnp = rdp->mynode;
+	rnp = rdp->mynode;	/* this is the outgoing CPU's rnp. */
 	mask = rdp->grpmask;	/* rnp->grplo is constant. */
 	do {
 		spin_lock(&rnp->lock);		/* irqs already disabled. */
@@ -881,42 +913,16 @@ static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp)
 			spin_unlock(&rnp->lock); /* irqs remain disabled. */
 			break;
 		}
-		rcu_preempt_offline_tasks(rsp, rnp);
+		rcu_preempt_offline_tasks(rsp, rnp, rdp);
 		mask = rnp->grpmask;
 		spin_unlock(&rnp->lock);	/* irqs remain disabled. */
 		rnp = rnp->parent;
 	} while (rnp != NULL);
 	lastcomp = rsp->completed;
 
-	spin_unlock(&rsp->onofflock);		/* irqs remain disabled. */
-
-	/* Being offline is a quiescent state, so go record it. */
-	cpu_quiet(cpu, rsp, rdp, lastcomp);
+	spin_unlock_irqrestore(&rsp->onofflock, flags);
 
-	/*
-	 * Move callbacks from the outgoing CPU to the running CPU.
-	 * Note that the outgoing CPU is now quiscent, so it is now
-	 * (uncharacteristically) safe to access its rcu_data structure.
-	 * Note also that we must carefully retain the order of the
-	 * outgoing CPU's callbacks in order for rcu_barrier() to work
-	 * correctly.  Finally, note that we start all the callbacks
-	 * afresh, even those that have passed through a grace period
-	 * and are therefore ready to invoke.  The theory is that hotplug
-	 * events are rare, and that if they are frequent enough to
-	 * indefinitely delay callbacks, you have far worse things to
-	 * be worrying about.
-	 */
-	rdp_me = rsp->rda[smp_processor_id()];
-	if (rdp->nxtlist != NULL) {
-		*rdp_me->nxttail[RCU_NEXT_TAIL] = rdp->nxtlist;
-		rdp_me->nxttail[RCU_NEXT_TAIL] = rdp->nxttail[RCU_NEXT_TAIL];
-		rdp->nxtlist = NULL;
-		for (i = 0; i < RCU_NEXT_SIZE; i++)
-			rdp->nxttail[i] = &rdp->nxtlist;
-		rdp_me->qlen += rdp->qlen;
-		rdp->qlen = 0;
-	}
-	local_irq_restore(flags);
+	rcu_adopt_orphan_cbs(rsp);
 }
 
 /*
@@ -934,6 +940,14 @@ static void rcu_offline_cpu(int cpu)
 
 #else /* #ifdef CONFIG_HOTPLUG_CPU */
 
+static void rcu_send_cbs_to_orphanage(struct rcu_state *rsp)
+{
+}
+
+static void rcu_adopt_orphan_cbs(struct rcu_state *rsp)
+{
+}
+
 static void rcu_offline_cpu(int cpu)
 {
 }
@@ -1066,33 +1080,32 @@ static int rcu_process_dyntick(struct rcu_state *rsp, long lastcomp,
 	int cpu;
 	unsigned long flags;
 	unsigned long mask;
-	struct rcu_node *rnp_cur = rsp->level[NUM_RCU_LVLS - 1];
-	struct rcu_node *rnp_end = &rsp->node[NUM_RCU_NODES];
+	struct rcu_node *rnp;
 
-	for (; rnp_cur < rnp_end; rnp_cur++) {
+	rcu_for_each_leaf_node(rsp, rnp) {
 		mask = 0;
-		spin_lock_irqsave(&rnp_cur->lock, flags);
+		spin_lock_irqsave(&rnp->lock, flags);
 		if (rsp->completed != lastcomp) {
-			spin_unlock_irqrestore(&rnp_cur->lock, flags);
+			spin_unlock_irqrestore(&rnp->lock, flags);
 			return 1;
 		}
-		if (rnp_cur->qsmask == 0) {
-			spin_unlock_irqrestore(&rnp_cur->lock, flags);
+		if (rnp->qsmask == 0) {
+			spin_unlock_irqrestore(&rnp->lock, flags);
 			continue;
 		}
-		cpu = rnp_cur->grplo;
+		cpu = rnp->grplo;
 		bit = 1;
-		for (; cpu <= rnp_cur->grphi; cpu++, bit <<= 1) {
-			if ((rnp_cur->qsmask & bit) != 0 && f(rsp->rda[cpu]))
+		for (; cpu <= rnp->grphi; cpu++, bit <<= 1) {
+			if ((rnp->qsmask & bit) != 0 && f(rsp->rda[cpu]))
 				mask |= bit;
 		}
 		if (mask != 0 && rsp->completed == lastcomp) {
 
-			/* cpu_quiet_msk() releases rnp_cur->lock. */
-			cpu_quiet_msk(mask, rsp, rnp_cur, flags);
+			/* cpu_quiet_msk() releases rnp->lock. */
+			cpu_quiet_msk(mask, rsp, rnp, flags);
 			continue;
 		}
-		spin_unlock_irqrestore(&rnp_cur->lock, flags);
+		spin_unlock_irqrestore(&rnp->lock, flags);
 	}
 	return 0;
 }
@@ -1108,7 +1121,7 @@ static void force_quiescent_state(struct rcu_state *rsp, int relaxed)
 	struct rcu_node *rnp = rcu_get_root(rsp);
 	u8 signaled;
 
-	if (ACCESS_ONCE(rsp->completed) == ACCESS_ONCE(rsp->gpnum))
+	if (!rcu_gp_in_progress(rsp))
 		return;  /* No grace period in progress, nothing to force. */
 	if (!spin_trylock_irqsave(&rsp->fqslock, flags)) {
 		rsp->n_force_qs_lh++; /* Inexact, can lose counts.  Tough! */
@@ -1267,7 +1280,7 @@ __call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu),
 	rdp->nxttail[RCU_NEXT_TAIL] = &head->next;
 
 	/* Start a new grace period if one not already started. */
-	if (ACCESS_ONCE(rsp->completed) == ACCESS_ONCE(rsp->gpnum)) {
+	if (!rcu_gp_in_progress(rsp)) {
 		unsigned long nestflag;
 		struct rcu_node *rnp_root = rcu_get_root(rsp);
 
@@ -1347,7 +1360,7 @@ static int __rcu_pending(struct rcu_state *rsp, struct rcu_data *rdp)
 	}
 
 	/* Has an RCU GP gone long enough to send resched IPIs &c? */
-	if (ACCESS_ONCE(rsp->completed) != ACCESS_ONCE(rsp->gpnum) &&
+	if (rcu_gp_in_progress(rsp) &&
 	    ((long)(ACCESS_ONCE(rsp->jiffies_force_qs) - jiffies) < 0)) {
 		rdp->n_rp_need_fqs++;
 		return 1;
@@ -1384,6 +1397,82 @@ int rcu_needs_cpu(int cpu)
 	       rcu_preempt_needs_cpu(cpu);
 }
 
+static DEFINE_PER_CPU(struct rcu_head, rcu_barrier_head) = {NULL};
+static atomic_t rcu_barrier_cpu_count;
+static DEFINE_MUTEX(rcu_barrier_mutex);
+static struct completion rcu_barrier_completion;
+
+static void rcu_barrier_callback(struct rcu_head *notused)
+{
+	if (atomic_dec_and_test(&rcu_barrier_cpu_count))
+		complete(&rcu_barrier_completion);
+}
+
+/*
+ * Called with preemption disabled, and from cross-cpu IRQ context.
+ */
+static void rcu_barrier_func(void *type)
+{
+	int cpu = smp_processor_id();
+	struct rcu_head *head = &per_cpu(rcu_barrier_head, cpu);
+	void (*call_rcu_func)(struct rcu_head *head,
+			      void (*func)(struct rcu_head *head));
+
+	atomic_inc(&rcu_barrier_cpu_count);
+	call_rcu_func = type;
+	call_rcu_func(head, rcu_barrier_callback);
+}
+
+/*
+ * Orchestrate the specified type of RCU barrier, waiting for all
+ * RCU callbacks of the specified type to complete.
+ */
+static void _rcu_barrier(struct rcu_state *rsp,
+			 void (*call_rcu_func)(struct rcu_head *head,
+					       void (*func)(struct rcu_head *head)))
+{
+	BUG_ON(in_interrupt());
+	/* Take mutex to serialize concurrent rcu_barrier() requests. */
+	mutex_lock(&rcu_barrier_mutex);
+	init_completion(&rcu_barrier_completion);
+	/*
+	 * Initialize rcu_barrier_cpu_count to 1, then invoke
+	 * rcu_barrier_func() on each CPU, so that each CPU also has
+	 * incremented rcu_barrier_cpu_count.  Only then is it safe to
+	 * decrement rcu_barrier_cpu_count -- otherwise the first CPU
+	 * might complete its grace period before all of the other CPUs
+	 * did their increment, causing this function to return too
+	 * early.
+	 */
+	atomic_set(&rcu_barrier_cpu_count, 1);
+	preempt_disable(); /* stop CPU_DYING from filling orphan_cbs_list */
+	rcu_adopt_orphan_cbs(rsp);
+	on_each_cpu(rcu_barrier_func, (void *)call_rcu_func, 1);
+	preempt_enable(); /* CPU_DYING can again fill orphan_cbs_list */
+	if (atomic_dec_and_test(&rcu_barrier_cpu_count))
+		complete(&rcu_barrier_completion);
+	wait_for_completion(&rcu_barrier_completion);
+	mutex_unlock(&rcu_barrier_mutex);
+}
+
+/**
+ * rcu_barrier_bh - Wait until all in-flight call_rcu_bh() callbacks complete.
+ */
+void rcu_barrier_bh(void)
+{
+	_rcu_barrier(&rcu_bh_state, call_rcu_bh);
+}
+EXPORT_SYMBOL_GPL(rcu_barrier_bh);
+
+/**
+ * rcu_barrier_sched - Wait for in-flight call_rcu_sched() callbacks.
+ */
+void rcu_barrier_sched(void)
+{
+	_rcu_barrier(&rcu_sched_state, call_rcu_sched);
+}
+EXPORT_SYMBOL_GPL(rcu_barrier_sched);
+
 /*
  * Do boot-time initialization of a CPU's per-CPU RCU data.
  */
@@ -1457,20 +1546,7 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptable)
 		rnp = rnp->parent;
 	} while (rnp != NULL && !(rnp->qsmaskinit & mask));
 
-	spin_unlock(&rsp->onofflock);		/* irqs remain disabled. */
-
-	/*
-	 * A new grace period might start here.  If so, we will be part of
-	 * it, and its gpnum will be greater than ours, so we will
-	 * participate.  It is also possible for the gpnum to have been
-	 * incremented before this function was called, and the bitmasks
-	 * to not be filled out until now, in which case we will also
-	 * participate due to our gpnum being behind.
-	 */
-
-	/* Since it is coming online, the CPU is in a quiescent state. */
-	cpu_quiet(cpu, rsp, rdp, lastcomp);
-	local_irq_restore(flags);
+	spin_unlock_irqrestore(&rsp->onofflock, flags);
 }
 
 static void __cpuinit rcu_online_cpu(int cpu)
@@ -1493,6 +1569,22 @@ int __cpuinit rcu_cpu_notify(struct notifier_block *self,
 	case CPU_UP_PREPARE_FROZEN:
 		rcu_online_cpu(cpu);
 		break;
+	case CPU_DYING:
+	case CPU_DYING_FROZEN:
+		/*
+		 * preempt_disable() in _rcu_barrier() prevents stop_machine(),
+		 * so when "on_each_cpu(rcu_barrier_func, (void *)type, 1);"
+		 * returns, all online cpus have queued rcu_barrier_func().
+		 * The dying CPU clears its cpu_online_mask bit and
+		 * moves all of its RCU callbacks to ->orphan_cbs_list
+		 * in the context of stop_machine(), so subsequent calls
+		 * to _rcu_barrier() will adopt these callbacks and only
+		 * then queue rcu_barrier_func() on all remaining CPUs.
+		 */
+		rcu_send_cbs_to_orphanage(&rcu_bh_state);
+		rcu_send_cbs_to_orphanage(&rcu_sched_state);
+		rcu_preempt_send_cbs_to_orphanage();
+		break;
 	case CPU_DEAD:
 	case CPU_DEAD_FROZEN:
 	case CPU_UP_CANCELED:
@@ -1555,7 +1647,8 @@ static void __init rcu_init_one(struct rcu_state *rsp)
 		cpustride *= rsp->levelspread[i];
 		rnp = rsp->level[i];
 		for (j = 0; j < rsp->levelcnt[i]; j++, rnp++) {
-			spin_lock_init(&rnp->lock);
+			if (rnp != rcu_get_root(rsp))
+				spin_lock_init(&rnp->lock);
 			rnp->gpnum = 0;
 			rnp->qsmask = 0;
 			rnp->qsmaskinit = 0;
@@ -1578,6 +1671,7 @@ static void __init rcu_init_one(struct rcu_state *rsp)
 			INIT_LIST_HEAD(&rnp->blocked_tasks[1]);
 		}
 	}
+	spin_lock_init(&rcu_get_root(rsp)->lock);
 }
 
 /*
@@ -1587,6 +1681,10 @@ static void __init rcu_init_one(struct rcu_state *rsp)
  */
 #define RCU_INIT_FLAVOR(rsp, rcu_data) \
 do { \
+	int i; \
+	int j; \
+	struct rcu_node *rnp; \
+	\
 	rcu_init_one(rsp); \
 	rnp = (rsp)->level[NUM_RCU_LVLS - 1]; \
 	j = 0; \
@@ -1599,31 +1697,8 @@ do { \
 	} \
 } while (0)
 
-#ifdef CONFIG_TREE_PREEMPT_RCU
-
-void __init __rcu_init_preempt(void)
-{
-	int i;			/* All used by RCU_INIT_FLAVOR(). */
-	int j;
-	struct rcu_node *rnp;
-
-	RCU_INIT_FLAVOR(&rcu_preempt_state, rcu_preempt_data);
-}
-
-#else /* #ifdef CONFIG_TREE_PREEMPT_RCU */
-
-void __init __rcu_init_preempt(void)
-{
-}
-
-#endif /* #else #ifdef CONFIG_TREE_PREEMPT_RCU */
-
 void __init __rcu_init(void)
 {
-	int i;			/* All used by RCU_INIT_FLAVOR(). */
-	int j;
-	struct rcu_node *rnp;
-
 	rcu_bootup_announce();
 #ifdef CONFIG_RCU_CPU_STALL_DETECTOR
 	printk(KERN_INFO "RCU-based detection of stalled CPUs is enabled.\n");
@@ -1634,6 +1709,4 @@ void __init __rcu_init(void)
 	open_softirq(RCU_SOFTIRQ, rcu_process_callbacks);
 }
 
-module_param(blimit, int, 0);
-module_param(qhimark, int, 0);
-module_param(qlowmark, int, 0);
+#include "rcutree_plugin.h"
diff --git a/kernel/rcutree.h b/kernel/rcutree.h
index bf8a6f9f134..b40ac570604 100644
--- a/kernel/rcutree.h
+++ b/kernel/rcutree.h
@@ -48,14 +48,14 @@
 #elif NR_CPUS <= RCU_FANOUT_SQ
 #  define NUM_RCU_LVLS	      2
 #  define NUM_RCU_LVL_0	      1
-#  define NUM_RCU_LVL_1	      (((NR_CPUS) + RCU_FANOUT - 1) / RCU_FANOUT)
+#  define NUM_RCU_LVL_1	      DIV_ROUND_UP(NR_CPUS, RCU_FANOUT)
 #  define NUM_RCU_LVL_2	      (NR_CPUS)
 #  define NUM_RCU_LVL_3	      0
 #elif NR_CPUS <= RCU_FANOUT_CUBE
 #  define NUM_RCU_LVLS	      3
 #  define NUM_RCU_LVL_0	      1
-#  define NUM_RCU_LVL_1	      (((NR_CPUS) + RCU_FANOUT_SQ - 1) / RCU_FANOUT_SQ)
-#  define NUM_RCU_LVL_2	      (((NR_CPUS) + (RCU_FANOUT) - 1) / (RCU_FANOUT))
+#  define NUM_RCU_LVL_1	      DIV_ROUND_UP(NR_CPUS, RCU_FANOUT_SQ)
+#  define NUM_RCU_LVL_2	      DIV_ROUND_UP(NR_CPUS, RCU_FANOUT)
 #  define NUM_RCU_LVL_3	      NR_CPUS
 #else
 # error "CONFIG_RCU_FANOUT insufficient for NR_CPUS"
@@ -79,15 +79,21 @@ struct rcu_dynticks {
  * Definition for node within the RCU grace-period-detection hierarchy.
  */
 struct rcu_node {
-	spinlock_t lock;
+	spinlock_t lock;	/* Root rcu_node's lock protects some */
+				/*  rcu_state fields as well as following. */
 	long	gpnum;		/* Current grace period for this node. */
 				/*  This will either be equal to or one */
 				/*  behind the root rcu_node's gpnum. */
 	unsigned long qsmask;	/* CPUs or groups that need to switch in */
 				/*  order for current grace period to proceed.*/
+				/*  In leaf rcu_node, each bit corresponds to */
+				/*  an rcu_data structure, otherwise, each */
+				/*  bit corresponds to a child rcu_node */
+				/*  structure. */
 	unsigned long qsmaskinit;
 				/* Per-GP initialization for qsmask. */
 	unsigned long grpmask;	/* Mask to apply to parent qsmask. */
+				/*  Only one bit will be set in this mask. */
 	int	grplo;		/* lowest-numbered CPU or group here. */
 	int	grphi;		/* highest-numbered CPU or group here. */
 	u8	grpnum;		/* CPU/group number for next level up. */
@@ -95,8 +101,23 @@ struct rcu_node {
 	struct rcu_node *parent;
 	struct list_head blocked_tasks[2];
 				/* Tasks blocked in RCU read-side critsect. */
+				/*  Grace period number (->gpnum) x blocked */
+				/*  by tasks on the (x & 0x1) element of the */
+				/*  blocked_tasks[] array. */
 } ____cacheline_internodealigned_in_smp;
 
+/*
+ * Do a full breadth-first scan of the rcu_node structures for the
+ * specified rcu_state structure.
+ */
+#define rcu_for_each_node_breadth_first(rsp, rnp) \
+	for ((rnp) = &(rsp)->node[0]; \
+	     (rnp) < &(rsp)->node[NUM_RCU_NODES]; (rnp)++)
+
+#define rcu_for_each_leaf_node(rsp, rnp) \
+	for ((rnp) = (rsp)->level[NUM_RCU_LVLS - 1]; \
+	     (rnp) < &(rsp)->node[NUM_RCU_NODES]; (rnp)++)
+
 /* Index values for nxttail array in struct rcu_data. */
 #define RCU_DONE_TAIL		0	/* Also RCU_WAIT head. */
 #define RCU_WAIT_TAIL		1	/* Also RCU_NEXT_READY head. */
@@ -126,23 +147,26 @@ struct rcu_data {
 	 * Any of the partitions might be empty, in which case the
 	 * pointer to that partition will be equal to the pointer for
 	 * the following partition.  When the list is empty, all of
-	 * the nxttail elements point to nxtlist, which is NULL.
+	 * the nxttail elements point to the ->nxtlist pointer itself,
+	 * which in that case is NULL.
 	 *
-	 * [*nxttail[RCU_NEXT_READY_TAIL], NULL = *nxttail[RCU_NEXT_TAIL]):
-	 *	Entries that might have arrived after current GP ended
-	 * [*nxttail[RCU_WAIT_TAIL], *nxttail[RCU_NEXT_READY_TAIL]):
-	 *	Entries known to have arrived before current GP ended
-	 * [*nxttail[RCU_DONE_TAIL], *nxttail[RCU_WAIT_TAIL]):
-	 *	Entries that batch # <= ->completed - 1: waiting for current GP
 	 * [nxtlist, *nxttail[RCU_DONE_TAIL]):
 	 *	Entries that batch # <= ->completed
 	 *	The grace period for these entries has completed, and
 	 *	the other grace-period-completed entries may be moved
 	 *	here temporarily in rcu_process_callbacks().
+	 * [*nxttail[RCU_DONE_TAIL], *nxttail[RCU_WAIT_TAIL]):
+	 *	Entries that batch # <= ->completed - 1: waiting for current GP
+	 * [*nxttail[RCU_WAIT_TAIL], *nxttail[RCU_NEXT_READY_TAIL]):
+	 *	Entries known to have arrived before current GP ended
+	 * [*nxttail[RCU_NEXT_READY_TAIL], *nxttail[RCU_NEXT_TAIL]):
+	 *	Entries that might have arrived after current GP ended
+	 *	Note that the value of *nxttail[RCU_NEXT_TAIL] will
+	 *	always be NULL, as this is the end of the list.
 	 */
 	struct rcu_head *nxtlist;
 	struct rcu_head **nxttail[RCU_NEXT_SIZE];
-	long		qlen; 	 	/* # of queued callbacks */
+	long		qlen;		/* # of queued callbacks */
 	long		blimit;		/* Upper limit on a processed batch */
 
 #ifdef CONFIG_NO_HZ
@@ -216,8 +240,19 @@ struct rcu_state {
 						/* Force QS state. */
 	long	gpnum;				/* Current gp number. */
 	long	completed;			/* # of last completed gp. */
+
+	/* End  of fields guarded by root rcu_node's lock. */
+
 	spinlock_t onofflock;			/* exclude on/offline and */
-						/*  starting new GP. */
+						/*  starting new GP.  Also */
+						/*  protects the following */
+						/*  orphan_cbs fields. */
+	struct rcu_head *orphan_cbs_list;	/* list of rcu_head structs */
+						/*  orphaned by all CPUs in */
+						/*  a given leaf rcu_node */
+						/*  going offline. */
+	struct rcu_head **orphan_cbs_tail;	/* And tail pointer. */
+	long orphan_qlen;			/* Number of orphaned cbs. */
 	spinlock_t fqslock;			/* Only one task forcing */
 						/*  quiescent states. */
 	unsigned long jiffies_force_qs;		/* Time at which to invoke */
@@ -255,5 +290,30 @@ extern struct rcu_state rcu_preempt_state;
 DECLARE_PER_CPU(struct rcu_data, rcu_preempt_data);
 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
 
-#endif /* #ifdef RCU_TREE_NONCORE */
+#else /* #ifdef RCU_TREE_NONCORE */
+
+/* Forward declarations for rcutree_plugin.h */
+static inline void rcu_bootup_announce(void);
+long rcu_batches_completed(void);
+static void rcu_preempt_note_context_switch(int cpu);
+static int rcu_preempted_readers(struct rcu_node *rnp);
+#ifdef CONFIG_RCU_CPU_STALL_DETECTOR
+static void rcu_print_task_stall(struct rcu_node *rnp);
+#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
+static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp);
+#ifdef CONFIG_HOTPLUG_CPU
+static void rcu_preempt_offline_tasks(struct rcu_state *rsp,
+				      struct rcu_node *rnp,
+				      struct rcu_data *rdp);
+static void rcu_preempt_offline_cpu(int cpu);
+#endif /* #ifdef CONFIG_HOTPLUG_CPU */
+static void rcu_preempt_check_callbacks(int cpu);
+static void rcu_preempt_process_callbacks(void);
+void call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu));
+static int rcu_preempt_pending(int cpu);
+static int rcu_preempt_needs_cpu(int cpu);
+static void __cpuinit rcu_preempt_init_percpu_data(int cpu);
+static void rcu_preempt_send_cbs_to_orphanage(void);
+static void __init __rcu_init_preempt(void);
 
+#endif /* #else #ifdef RCU_TREE_NONCORE */
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index 47789369ea5..c0cb783aa16 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -64,22 +64,31 @@ EXPORT_SYMBOL_GPL(rcu_batches_completed);
  * not in a quiescent state.  There might be any number of tasks blocked
  * while in an RCU read-side critical section.
  */
-static void rcu_preempt_qs_record(int cpu)
+static void rcu_preempt_qs(int cpu)
 {
 	struct rcu_data *rdp = &per_cpu(rcu_preempt_data, cpu);
-	rdp->passed_quiesc = 1;
 	rdp->passed_quiesc_completed = rdp->completed;
+	barrier();
+	rdp->passed_quiesc = 1;
 }
 
 /*
- * We have entered the scheduler or are between softirqs in ksoftirqd.
- * If we are in an RCU read-side critical section, we need to reflect
- * that in the state of the rcu_node structure corresponding to this CPU.
- * Caller must disable hardirqs.
+ * We have entered the scheduler, and the current task might soon be
+ * context-switched away from.  If this task is in an RCU read-side
+ * critical section, we will no longer be able to rely on the CPU to
+ * record that fact, so we enqueue the task on the appropriate entry
+ * of the blocked_tasks[] array.  The task will dequeue itself when
+ * it exits the outermost enclosing RCU read-side critical section.
+ * Therefore, the current grace period cannot be permitted to complete
+ * until the blocked_tasks[] entry indexed by the low-order bit of
+ * rnp->gpnum empties.
+ *
+ * Caller must disable preemption.
  */
-static void rcu_preempt_qs(int cpu)
+static void rcu_preempt_note_context_switch(int cpu)
 {
 	struct task_struct *t = current;
+	unsigned long flags;
 	int phase;
 	struct rcu_data *rdp;
 	struct rcu_node *rnp;
@@ -90,7 +99,7 @@ static void rcu_preempt_qs(int cpu)
 		/* Possibly blocking in an RCU read-side critical section. */
 		rdp = rcu_preempt_state.rda[cpu];
 		rnp = rdp->mynode;
-		spin_lock(&rnp->lock);
+		spin_lock_irqsave(&rnp->lock, flags);
 		t->rcu_read_unlock_special |= RCU_READ_UNLOCK_BLOCKED;
 		t->rcu_blocked_node = rnp;
 
@@ -103,11 +112,15 @@ static void rcu_preempt_qs(int cpu)
 		 * state for the current grace period), then as long
 		 * as that task remains queued, the current grace period
 		 * cannot end.
+		 *
+		 * But first, note that the current CPU must still be
+		 * on line!
 		 */
-		phase = !(rnp->qsmask & rdp->grpmask) ^ (rnp->gpnum & 0x1);
+		WARN_ON_ONCE((rdp->grpmask & rnp->qsmaskinit) == 0);
+		WARN_ON_ONCE(!list_empty(&t->rcu_node_entry));
+		phase = (rnp->gpnum + !(rnp->qsmask & rdp->grpmask)) & 0x1;
 		list_add(&t->rcu_node_entry, &rnp->blocked_tasks[phase]);
-		smp_mb();  /* Ensure later ctxt swtch seen after above. */
-		spin_unlock(&rnp->lock);
+		spin_unlock_irqrestore(&rnp->lock, flags);
 	}
 
 	/*
@@ -119,9 +132,10 @@ static void rcu_preempt_qs(int cpu)
 	 * grace period, then the fact that the task has been enqueued
 	 * means that we continue to block the current grace period.
 	 */
-	rcu_preempt_qs_record(cpu);
-	t->rcu_read_unlock_special &= ~(RCU_READ_UNLOCK_NEED_QS |
-					RCU_READ_UNLOCK_GOT_QS);
+	rcu_preempt_qs(cpu);
+	local_irq_save(flags);
+	t->rcu_read_unlock_special &= ~RCU_READ_UNLOCK_NEED_QS;
+	local_irq_restore(flags);
 }
 
 /*
@@ -136,6 +150,16 @@ void __rcu_read_lock(void)
 }
 EXPORT_SYMBOL_GPL(__rcu_read_lock);
 
+/*
+ * Check for preempted RCU readers blocking the current grace period
+ * for the specified rcu_node structure.  If the caller needs a reliable
+ * answer, it must hold the rcu_node's ->lock.
+ */
+static int rcu_preempted_readers(struct rcu_node *rnp)
+{
+	return !list_empty(&rnp->blocked_tasks[rnp->gpnum & 0x1]);
+}
+
 static void rcu_read_unlock_special(struct task_struct *t)
 {
 	int empty;
@@ -157,7 +181,7 @@ static void rcu_read_unlock_special(struct task_struct *t)
 	special = t->rcu_read_unlock_special;
 	if (special & RCU_READ_UNLOCK_NEED_QS) {
 		t->rcu_read_unlock_special &= ~RCU_READ_UNLOCK_NEED_QS;
-		t->rcu_read_unlock_special |= RCU_READ_UNLOCK_GOT_QS;
+		rcu_preempt_qs(smp_processor_id());
 	}
 
 	/* Hardware IRQ handlers cannot block. */
@@ -177,12 +201,12 @@ static void rcu_read_unlock_special(struct task_struct *t)
 		 */
 		for (;;) {
 			rnp = t->rcu_blocked_node;
-			spin_lock(&rnp->lock);
+			spin_lock(&rnp->lock);  /* irqs already disabled. */
 			if (rnp == t->rcu_blocked_node)
 				break;
-			spin_unlock(&rnp->lock);
+			spin_unlock(&rnp->lock);  /* irqs remain disabled. */
 		}
-		empty = list_empty(&rnp->blocked_tasks[rnp->gpnum & 0x1]);
+		empty = !rcu_preempted_readers(rnp);
 		list_del_init(&t->rcu_node_entry);
 		t->rcu_blocked_node = NULL;
 
@@ -193,10 +217,9 @@ static void rcu_read_unlock_special(struct task_struct *t)
 		 * drop rnp->lock and restore irq.
 		 */
 		if (!empty && rnp->qsmask == 0 &&
-		    list_empty(&rnp->blocked_tasks[rnp->gpnum & 0x1])) {
-			t->rcu_read_unlock_special &=
-				~(RCU_READ_UNLOCK_NEED_QS |
-				  RCU_READ_UNLOCK_GOT_QS);
+		    !rcu_preempted_readers(rnp)) {
+			struct rcu_node *rnp_p;
+
 			if (rnp->parent == NULL) {
 				/* Only one rcu_node in the tree. */
 				cpu_quiet_msk_finish(&rcu_preempt_state, flags);
@@ -205,9 +228,10 @@ static void rcu_read_unlock_special(struct task_struct *t)
 			/* Report up the rest of the hierarchy. */
 			mask = rnp->grpmask;
 			spin_unlock_irqrestore(&rnp->lock, flags);
-			rnp = rnp->parent;
-			spin_lock_irqsave(&rnp->lock, flags);
-			cpu_quiet_msk(mask, &rcu_preempt_state, rnp, flags);
+			rnp_p = rnp->parent;
+			spin_lock_irqsave(&rnp_p->lock, flags);
+			WARN_ON_ONCE(rnp->qsmask);
+			cpu_quiet_msk(mask, &rcu_preempt_state, rnp_p, flags);
 			return;
 		}
 		spin_unlock(&rnp->lock);
@@ -243,12 +267,12 @@ static void rcu_print_task_stall(struct rcu_node *rnp)
 {
 	unsigned long flags;
 	struct list_head *lp;
-	int phase = rnp->gpnum & 0x1;
+	int phase;
 	struct task_struct *t;
 
-	if (!list_empty(&rnp->blocked_tasks[phase])) {
+	if (rcu_preempted_readers(rnp)) {
 		spin_lock_irqsave(&rnp->lock, flags);
-		phase = rnp->gpnum & 0x1; /* re-read under lock. */
+		phase = rnp->gpnum & 0x1;
 		lp = &rnp->blocked_tasks[phase];
 		list_for_each_entry(t, lp, rcu_node_entry)
 			printk(" P%d", t->pid);
@@ -259,13 +283,16 @@ static void rcu_print_task_stall(struct rcu_node *rnp)
 #endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
 
 /*
- * Check for preempted RCU readers for the specified rcu_node structure.
- * If the caller needs a reliable answer, it must hold the rcu_node's
- * >lock.
+ * Check that the list of blocked tasks for the newly completed grace
+ * period is in fact empty.  It is a serious bug to complete a grace
+ * period that still has RCU readers blocked!  This function must be
+ * invoked -before- updating this rnp's ->gpnum, and the rnp's ->lock
+ * must be held by the caller.
  */
-static int rcu_preempted_readers(struct rcu_node *rnp)
+static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp)
 {
-	return !list_empty(&rnp->blocked_tasks[rnp->gpnum & 0x1]);
+	WARN_ON_ONCE(rcu_preempted_readers(rnp));
+	WARN_ON_ONCE(rnp->qsmask);
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
@@ -280,7 +307,8 @@ static int rcu_preempted_readers(struct rcu_node *rnp)
  * The caller must hold rnp->lock with irqs disabled.
  */
 static void rcu_preempt_offline_tasks(struct rcu_state *rsp,
-				      struct rcu_node *rnp)
+				      struct rcu_node *rnp,
+				      struct rcu_data *rdp)
 {
 	int i;
 	struct list_head *lp;
@@ -292,6 +320,9 @@ static void rcu_preempt_offline_tasks(struct rcu_state *rsp,
 		WARN_ONCE(1, "Last CPU thought to be offlined?");
 		return;  /* Shouldn't happen: at least one CPU online. */
 	}
+	WARN_ON_ONCE(rnp != rdp->mynode &&
+		     (!list_empty(&rnp->blocked_tasks[0]) ||
+		      !list_empty(&rnp->blocked_tasks[1])));
 
 	/*
 	 * Move tasks up to root rcu_node.  Rely on the fact that the
@@ -335,20 +366,12 @@ static void rcu_preempt_check_callbacks(int cpu)
 	struct task_struct *t = current;
 
 	if (t->rcu_read_lock_nesting == 0) {
-		t->rcu_read_unlock_special &=
-			~(RCU_READ_UNLOCK_NEED_QS | RCU_READ_UNLOCK_GOT_QS);
-		rcu_preempt_qs_record(cpu);
+		t->rcu_read_unlock_special &= ~RCU_READ_UNLOCK_NEED_QS;
+		rcu_preempt_qs(cpu);
 		return;
 	}
-	if (per_cpu(rcu_preempt_data, cpu).qs_pending) {
-		if (t->rcu_read_unlock_special & RCU_READ_UNLOCK_GOT_QS) {
-			rcu_preempt_qs_record(cpu);
-			t->rcu_read_unlock_special &= ~RCU_READ_UNLOCK_GOT_QS;
-		} else if (!(t->rcu_read_unlock_special &
-			     RCU_READ_UNLOCK_NEED_QS)) {
-			t->rcu_read_unlock_special |= RCU_READ_UNLOCK_NEED_QS;
-		}
-	}
+	if (per_cpu(rcu_preempt_data, cpu).qs_pending)
+		t->rcu_read_unlock_special |= RCU_READ_UNLOCK_NEED_QS;
 }
 
 /*
@@ -387,6 +410,15 @@ static int rcu_preempt_needs_cpu(int cpu)
 	return !!per_cpu(rcu_preempt_data, cpu).nxtlist;
 }
 
+/**
+ * rcu_barrier - Wait until all in-flight call_rcu() callbacks complete.
+ */
+void rcu_barrier(void)
+{
+	_rcu_barrier(&rcu_preempt_state, call_rcu);
+}
+EXPORT_SYMBOL_GPL(rcu_barrier);
+
 /*
  * Initialize preemptable RCU's per-CPU data.
  */
@@ -396,6 +428,22 @@ static void __cpuinit rcu_preempt_init_percpu_data(int cpu)
 }
 
 /*
+ * Move preemptable RCU's callbacks to ->orphan_cbs_list.
+ */
+static void rcu_preempt_send_cbs_to_orphanage(void)
+{
+	rcu_send_cbs_to_orphanage(&rcu_preempt_state);
+}
+
+/*
+ * Initialize preemptable RCU's state structures.
+ */
+static void __init __rcu_init_preempt(void)
+{
+	RCU_INIT_FLAVOR(&rcu_preempt_state, rcu_preempt_data);
+}
+
+/*
  * Check for a task exiting while in a preemptable-RCU read-side
  * critical section, clean up if so.  No need to issue warnings,
  * as debug_check_no_locks_held() already does this if lockdep
@@ -434,8 +482,17 @@ EXPORT_SYMBOL_GPL(rcu_batches_completed);
  * Because preemptable RCU does not exist, we never have to check for
  * CPUs being in quiescent states.
  */
-static void rcu_preempt_qs(int cpu)
+static void rcu_preempt_note_context_switch(int cpu)
+{
+}
+
+/*
+ * Because preemptable RCU does not exist, there are never any preempted
+ * RCU readers.
+ */
+static int rcu_preempted_readers(struct rcu_node *rnp)
 {
+	return 0;
 }
 
 #ifdef CONFIG_RCU_CPU_STALL_DETECTOR
@@ -451,12 +508,13 @@ static void rcu_print_task_stall(struct rcu_node *rnp)
 #endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
 
 /*
- * Because preemptable RCU does not exist, there are never any preempted
- * RCU readers.
+ * Because there is no preemptable RCU, there can be no readers blocked,
+ * so there is no need to check for blocked tasks.  So check only for
+ * bogus qsmask values.
  */
-static int rcu_preempted_readers(struct rcu_node *rnp)
+static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp)
 {
-	return 0;
+	WARN_ON_ONCE(rnp->qsmask);
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
@@ -466,7 +524,8 @@ static int rcu_preempted_readers(struct rcu_node *rnp)
  * tasks that were blocked within RCU read-side critical sections.
  */
 static void rcu_preempt_offline_tasks(struct rcu_state *rsp,
-				      struct rcu_node *rnp)
+				      struct rcu_node *rnp,
+				      struct rcu_data *rdp)
 {
 }
 
@@ -484,7 +543,7 @@ static void rcu_preempt_offline_cpu(int cpu)
  * Because preemptable RCU does not exist, it never has any callbacks
  * to check.
  */
-void rcu_preempt_check_callbacks(int cpu)
+static void rcu_preempt_check_callbacks(int cpu)
 {
 }
 
@@ -492,7 +551,7 @@ void rcu_preempt_check_callbacks(int cpu)
  * Because preemptable RCU does not exist, it never has any callbacks
  * to process.
  */
-void rcu_preempt_process_callbacks(void)
+static void rcu_preempt_process_callbacks(void)
 {
 }
 
@@ -522,6 +581,16 @@ static int rcu_preempt_needs_cpu(int cpu)
 }
 
 /*
+ * Because preemptable RCU does not exist, rcu_barrier() is just
+ * another name for rcu_barrier_sched().
+ */
+void rcu_barrier(void)
+{
+	rcu_barrier_sched();
+}
+EXPORT_SYMBOL_GPL(rcu_barrier);
+
+/*
  * Because preemptable RCU does not exist, there is no per-CPU
  * data to initialize.
  */
@@ -529,4 +598,18 @@ static void __cpuinit rcu_preempt_init_percpu_data(int cpu)
 {
 }
 
+/*
+ * Because there is no preemptable RCU, there are no callbacks to move.
+ */
+static void rcu_preempt_send_cbs_to_orphanage(void)
+{
+}
+
+/*
+ * Because preemptable RCU does not exist, it need not be initialized.
+ */
+static void __init __rcu_init_preempt(void)
+{
+}
+
 #endif /* #else #ifdef CONFIG_TREE_PREEMPT_RCU */
diff --git a/kernel/rcutree_trace.c b/kernel/rcutree_trace.c
index 0ea1bff6972..4b31c779e62 100644
--- a/kernel/rcutree_trace.c
+++ b/kernel/rcutree_trace.c
@@ -20,7 +20,7 @@
  * Papers:  http://www.rdrop.com/users/paulmck/RCU
  *
  * For detailed explanation of Read-Copy Update mechanism see -
- * 		Documentation/RCU
+ *		Documentation/RCU
  *
  */
 #include <linux/types.h>
@@ -93,7 +93,7 @@ static int rcudata_open(struct inode *inode, struct file *file)
 	return single_open(file, show_rcudata, NULL);
 }
 
-static struct file_operations rcudata_fops = {
+static const struct file_operations rcudata_fops = {
 	.owner = THIS_MODULE,
 	.open = rcudata_open,
 	.read = seq_read,
@@ -145,7 +145,7 @@ static int rcudata_csv_open(struct inode *inode, struct file *file)
 	return single_open(file, show_rcudata_csv, NULL);
 }
 
-static struct file_operations rcudata_csv_fops = {
+static const struct file_operations rcudata_csv_fops = {
 	.owner = THIS_MODULE,
 	.open = rcudata_csv_open,
 	.read = seq_read,
@@ -159,13 +159,13 @@ static void print_one_rcu_state(struct seq_file *m, struct rcu_state *rsp)
 	struct rcu_node *rnp;
 
 	seq_printf(m, "c=%ld g=%ld s=%d jfq=%ld j=%x "
-	              "nfqs=%lu/nfqsng=%lu(%lu) fqlh=%lu\n",
+		      "nfqs=%lu/nfqsng=%lu(%lu) fqlh=%lu oqlen=%ld\n",
 		   rsp->completed, rsp->gpnum, rsp->signaled,
 		   (long)(rsp->jiffies_force_qs - jiffies),
 		   (int)(jiffies & 0xffff),
 		   rsp->n_force_qs, rsp->n_force_qs_ngp,
 		   rsp->n_force_qs - rsp->n_force_qs_ngp,
-		   rsp->n_force_qs_lh);
+		   rsp->n_force_qs_lh, rsp->orphan_qlen);
 	for (rnp = &rsp->node[0]; rnp - &rsp->node[0] < NUM_RCU_NODES; rnp++) {
 		if (rnp->level != level) {
 			seq_puts(m, "\n");
@@ -196,7 +196,7 @@ static int rcuhier_open(struct inode *inode, struct file *file)
 	return single_open(file, show_rcuhier, NULL);
 }
 
-static struct file_operations rcuhier_fops = {
+static const struct file_operations rcuhier_fops = {
 	.owner = THIS_MODULE,
 	.open = rcuhier_open,
 	.read = seq_read,
@@ -222,7 +222,7 @@ static int rcugp_open(struct inode *inode, struct file *file)
 	return single_open(file, show_rcugp, NULL);
 }
 
-static struct file_operations rcugp_fops = {
+static const struct file_operations rcugp_fops = {
 	.owner = THIS_MODULE,
 	.open = rcugp_open,
 	.read = seq_read,
@@ -276,7 +276,7 @@ static int rcu_pending_open(struct inode *inode, struct file *file)
 	return single_open(file, show_rcu_pending, NULL);
 }
 
-static struct file_operations rcu_pending_fops = {
+static const struct file_operations rcu_pending_fops = {
 	.owner = THIS_MODULE,
 	.open = rcu_pending_open,
 	.read = seq_read,
diff --git a/kernel/relay.c b/kernel/relay.c
index bc188549788..760c26209a3 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -60,7 +60,7 @@ static int relay_buf_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 /*
  * vm_ops for relay file mappings.
  */
-static struct vm_operations_struct relay_file_mmap_ops = {
+static const struct vm_operations_struct relay_file_mmap_ops = {
 	.fault = relay_buf_fault,
 	.close = relay_file_mmap_close,
 };
diff --git a/kernel/res_counter.c b/kernel/res_counter.c
index e1338f07431..bcdabf37c40 100644
--- a/kernel/res_counter.c
+++ b/kernel/res_counter.c
@@ -19,6 +19,7 @@ void res_counter_init(struct res_counter *counter, struct res_counter *parent)
 {
 	spin_lock_init(&counter->lock);
 	counter->limit = RESOURCE_MAX;
+	counter->soft_limit = RESOURCE_MAX;
 	counter->parent = parent;
 }
 
@@ -101,6 +102,8 @@ res_counter_member(struct res_counter *counter, int member)
 		return &counter->limit;
 	case RES_FAILCNT:
 		return &counter->failcnt;
+	case RES_SOFT_LIMIT:
+		return &counter->soft_limit;
 	};
 
 	BUG();
diff --git a/kernel/resource.c b/kernel/resource.c
index 78b087221c1..fb11a58b959 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -223,13 +223,13 @@ int release_resource(struct resource *old)
 
 EXPORT_SYMBOL(release_resource);
 
-#if defined(CONFIG_MEMORY_HOTPLUG) && !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
+#if !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
 /*
  * Finds the lowest memory reosurce exists within [res->start.res->end)
- * the caller must specify res->start, res->end, res->flags.
+ * the caller must specify res->start, res->end, res->flags and "name".
  * If found, returns 0, res is overwritten, if not found, returns -1.
  */
-static int find_next_system_ram(struct resource *res)
+static int find_next_system_ram(struct resource *res, char *name)
 {
 	resource_size_t start, end;
 	struct resource *p;
@@ -245,6 +245,8 @@ static int find_next_system_ram(struct resource *res)
 		/* system ram is just marked as IORESOURCE_MEM */
 		if (p->flags != res->flags)
 			continue;
+		if (name && strcmp(p->name, name))
+			continue;
 		if (p->start > end) {
 			p = NULL;
 			break;
@@ -262,19 +264,26 @@ static int find_next_system_ram(struct resource *res)
 		res->end = p->end;
 	return 0;
 }
-int
-walk_memory_resource(unsigned long start_pfn, unsigned long nr_pages, void *arg,
-			int (*func)(unsigned long, unsigned long, void *))
+
+/*
+ * This function calls callback against all memory range of "System RAM"
+ * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY.
+ * Now, this function is only for "System RAM".
+ */
+int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
+		void *arg, int (*func)(unsigned long, unsigned long, void *))
 {
 	struct resource res;
 	unsigned long pfn, len;
 	u64 orig_end;
 	int ret = -1;
+
 	res.start = (u64) start_pfn << PAGE_SHIFT;
 	res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
 	res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 	orig_end = res.end;
-	while ((res.start < res.end) && (find_next_system_ram(&res) >= 0)) {
+	while ((res.start < res.end) &&
+		(find_next_system_ram(&res, "System RAM") >= 0)) {
 		pfn = (unsigned long)(res.start >> PAGE_SHIFT);
 		len = (unsigned long)((res.end + 1 - res.start) >> PAGE_SHIFT);
 		ret = (*func)(pfn, len, arg);
diff --git a/kernel/sched.c b/kernel/sched.c
index a56446d7fda..e5205811c19 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -39,7 +39,7 @@
 #include <linux/completion.h>
 #include <linux/kernel_stat.h>
 #include <linux/debug_locks.h>
-#include <linux/perf_counter.h>
+#include <linux/perf_event.h>
 #include <linux/security.h>
 #include <linux/notifier.h>
 #include <linux/profile.h>
@@ -676,6 +676,7 @@ inline void update_rq_clock(struct rq *rq)
 
 /**
  * runqueue_is_locked
+ * @cpu: the processor in question.
  *
  * Returns true if the current cpu runqueue is locked.
  * This interface allows printk to be called with the runqueue lock
@@ -780,7 +781,7 @@ static int sched_feat_open(struct inode *inode, struct file *filp)
 	return single_open(filp, sched_feat_show, NULL);
 }
 
-static struct file_operations sched_feat_fops = {
+static const struct file_operations sched_feat_fops = {
 	.open		= sched_feat_open,
 	.write		= sched_feat_write,
 	.read		= seq_read,
@@ -2053,7 +2054,7 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
 		if (task_hot(p, old_rq->clock, NULL))
 			schedstat_inc(p, se.nr_forced2_migrations);
 #endif
-		perf_swcounter_event(PERF_COUNT_SW_CPU_MIGRATIONS,
+		perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS,
 				     1, 1, NULL, 0);
 	}
 	p->se.vruntime -= old_cfsrq->min_vruntime -
@@ -2311,7 +2312,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state,
 {
 	int cpu, orig_cpu, this_cpu, success = 0;
 	unsigned long flags;
-	struct rq *rq;
+	struct rq *rq, *orig_rq;
 
 	if (!sched_feat(SYNC_WAKEUPS))
 		wake_flags &= ~WF_SYNC;
@@ -2319,7 +2320,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state,
 	this_cpu = get_cpu();
 
 	smp_wmb();
-	rq = task_rq_lock(p, &flags);
+	rq = orig_rq = task_rq_lock(p, &flags);
 	update_rq_clock(rq);
 	if (!(p->state & state))
 		goto out;
@@ -2350,6 +2351,10 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state,
 		set_task_cpu(p, cpu);
 
 	rq = task_rq_lock(p, &flags);
+
+	if (rq != orig_rq)
+		update_rq_clock(rq);
+
 	WARN_ON(p->state != TASK_WAKING);
 	cpu = task_cpu(p);
 
@@ -2515,22 +2520,17 @@ void sched_fork(struct task_struct *p, int clone_flags)
 	__sched_fork(p);
 
 	/*
-	 * Make sure we do not leak PI boosting priority to the child.
-	 */
-	p->prio = current->normal_prio;
-
-	/*
 	 * Revert to default priority/policy on fork if requested.
 	 */
 	if (unlikely(p->sched_reset_on_fork)) {
-		if (p->policy == SCHED_FIFO || p->policy == SCHED_RR)
+		if (p->policy == SCHED_FIFO || p->policy == SCHED_RR) {
 			p->policy = SCHED_NORMAL;
-
-		if (p->normal_prio < DEFAULT_PRIO)
-			p->prio = DEFAULT_PRIO;
+			p->normal_prio = p->static_prio;
+		}
 
 		if (PRIO_TO_NICE(p->static_prio) < 0) {
 			p->static_prio = NICE_TO_PRIO(0);
+			p->normal_prio = p->static_prio;
 			set_load_weight(p);
 		}
 
@@ -2541,6 +2541,11 @@ void sched_fork(struct task_struct *p, int clone_flags)
 		p->sched_reset_on_fork = 0;
 	}
 
+	/*
+	 * Make sure we do not leak PI boosting priority to the child.
+	 */
+	p->prio = current->normal_prio;
+
 	if (!rt_prio(p->prio))
 		p->sched_class = &fair_sched_class;
 
@@ -2581,8 +2586,6 @@ void wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
 	BUG_ON(p->state != TASK_RUNNING);
 	update_rq_clock(rq);
 
-	p->prio = effective_prio(p);
-
 	if (!p->sched_class->task_new || !current->se.on_rq) {
 		activate_task(rq, p, 0);
 	} else {
@@ -2718,7 +2721,7 @@ static void finish_task_switch(struct rq *rq, struct task_struct *prev)
 	 */
 	prev_state = prev->state;
 	finish_arch_switch(prev);
-	perf_counter_task_sched_in(current, cpu_of(rq));
+	perf_event_task_sched_in(current, cpu_of(rq));
 	finish_lock_switch(rq, prev);
 
 	fire_sched_in_preempt_notifiers(current);
@@ -2904,6 +2907,19 @@ unsigned long nr_iowait(void)
 	return sum;
 }
 
+unsigned long nr_iowait_cpu(void)
+{
+	struct rq *this = this_rq();
+	return atomic_read(&this->nr_iowait);
+}
+
+unsigned long this_cpu_load(void)
+{
+	struct rq *this = this_rq();
+	return this->cpu_load[0];
+}
+
+
 /* Variables and functions for calc_load */
 static atomic_long_t calc_load_tasks;
 static unsigned long calc_load_update;
@@ -3645,6 +3661,7 @@ static void update_group_power(struct sched_domain *sd, int cpu)
 
 /**
  * update_sg_lb_stats - Update sched_group's statistics for load balancing.
+ * @sd: The sched_domain whose statistics are to be updated.
  * @group: sched_group whose statistics are to be updated.
  * @this_cpu: Cpu for which load balance is currently performed.
  * @idle: Idle status of this_cpu
@@ -5079,17 +5096,16 @@ void account_idle_time(cputime_t cputime)
  */
 void account_process_tick(struct task_struct *p, int user_tick)
 {
-	cputime_t one_jiffy = jiffies_to_cputime(1);
-	cputime_t one_jiffy_scaled = cputime_to_scaled(one_jiffy);
+	cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy);
 	struct rq *rq = this_rq();
 
 	if (user_tick)
-		account_user_time(p, one_jiffy, one_jiffy_scaled);
+		account_user_time(p, cputime_one_jiffy, one_jiffy_scaled);
 	else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET))
-		account_system_time(p, HARDIRQ_OFFSET, one_jiffy,
+		account_system_time(p, HARDIRQ_OFFSET, cputime_one_jiffy,
 				    one_jiffy_scaled);
 	else
-		account_idle_time(one_jiffy);
+		account_idle_time(cputime_one_jiffy);
 }
 
 /*
@@ -5193,7 +5209,7 @@ void scheduler_tick(void)
 	curr->sched_class->task_tick(rq, curr, 0);
 	spin_unlock(&rq->lock);
 
-	perf_counter_task_tick(curr, cpu);
+	perf_event_task_tick(curr, cpu);
 
 #ifdef CONFIG_SMP
 	rq->idle_at_tick = idle_cpu(cpu);
@@ -5409,7 +5425,7 @@ need_resched_nonpreemptible:
 
 	if (likely(prev != next)) {
 		sched_info_switch(prev, next);
-		perf_counter_task_sched_out(prev, next, cpu);
+		perf_event_task_sched_out(prev, next, cpu);
 
 		rq->nr_switches++;
 		rq->curr = next;
@@ -6708,9 +6724,6 @@ EXPORT_SYMBOL(yield);
 /*
  * This task is about to go to sleep on IO. Increment rq->nr_iowait so
  * that process accounting knows that this is a task in IO wait state.
- *
- * But don't do that if it is a deliberate, throttling IO wait (this task
- * has set its backing_dev_info: the queue against which it should throttle)
  */
 void __sched io_schedule(void)
 {
@@ -7671,7 +7684,7 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
 /*
  * Register at high priority so that task migration (migrate_all_tasks)
  * happens before everything else.  This has to be lower priority than
- * the notifier in the perf_counter subsystem, though.
+ * the notifier in the perf_event subsystem, though.
  */
 static struct notifier_block __cpuinitdata migration_notifier = {
 	.notifier_call = migration_call,
@@ -9524,7 +9537,7 @@ void __init sched_init(void)
 	alloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT);
 #endif /* SMP */
 
-	perf_counter_init();
+	perf_event_init();
 
 	scheduler_running = 1;
 }
@@ -10296,7 +10309,7 @@ static int sched_rt_global_constraints(void)
 #endif /* CONFIG_RT_GROUP_SCHED */
 
 int sched_rt_handler(struct ctl_table *table, int write,
-		struct file *filp, void __user *buffer, size_t *lenp,
+		void __user *buffer, size_t *lenp,
 		loff_t *ppos)
 {
 	int ret;
@@ -10307,7 +10320,7 @@ int sched_rt_handler(struct ctl_table *table, int write,
 	old_period = sysctl_sched_rt_period;
 	old_runtime = sysctl_sched_rt_runtime;
 
-	ret = proc_dointvec(table, write, filp, buffer, lenp, ppos);
+	ret = proc_dointvec(table, write, buffer, lenp, ppos);
 
 	if (!ret && write) {
 		ret = sched_rt_global_constraints();
@@ -10361,8 +10374,7 @@ cpu_cgroup_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp)
 }
 
 static int
-cpu_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
-		      struct task_struct *tsk)
+cpu_cgroup_can_attach_task(struct cgroup *cgrp, struct task_struct *tsk)
 {
 #ifdef CONFIG_RT_GROUP_SCHED
 	if (!sched_rt_can_attach(cgroup_tg(cgrp), tsk))
@@ -10372,15 +10384,45 @@ cpu_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
 	if (tsk->sched_class != &fair_sched_class)
 		return -EINVAL;
 #endif
+	return 0;
+}
 
+static int
+cpu_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
+		      struct task_struct *tsk, bool threadgroup)
+{
+	int retval = cpu_cgroup_can_attach_task(cgrp, tsk);
+	if (retval)
+		return retval;
+	if (threadgroup) {
+		struct task_struct *c;
+		rcu_read_lock();
+		list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) {
+			retval = cpu_cgroup_can_attach_task(cgrp, c);
+			if (retval) {
+				rcu_read_unlock();
+				return retval;
+			}
+		}
+		rcu_read_unlock();
+	}
 	return 0;
 }
 
 static void
 cpu_cgroup_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
-			struct cgroup *old_cont, struct task_struct *tsk)
+		  struct cgroup *old_cont, struct task_struct *tsk,
+		  bool threadgroup)
 {
 	sched_move_task(tsk);
+	if (threadgroup) {
+		struct task_struct *c;
+		rcu_read_lock();
+		list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) {
+			sched_move_task(c);
+		}
+		rcu_read_unlock();
+	}
 }
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
diff --git a/kernel/sched_clock.c b/kernel/sched_clock.c
index e1d16c9a768..479ce5682d7 100644
--- a/kernel/sched_clock.c
+++ b/kernel/sched_clock.c
@@ -48,13 +48,6 @@ static __read_mostly int sched_clock_running;
 __read_mostly int sched_clock_stable;
 
 struct sched_clock_data {
-	/*
-	 * Raw spinlock - this is a special case: this might be called
-	 * from within instrumentation code so we dont want to do any
-	 * instrumentation ourselves.
-	 */
-	raw_spinlock_t		lock;
-
 	u64			tick_raw;
 	u64			tick_gtod;
 	u64			clock;
@@ -80,7 +73,6 @@ void sched_clock_init(void)
 	for_each_possible_cpu(cpu) {
 		struct sched_clock_data *scd = cpu_sdc(cpu);
 
-		scd->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
 		scd->tick_raw = 0;
 		scd->tick_gtod = ktime_now;
 		scd->clock = ktime_now;
@@ -109,14 +101,19 @@ static inline u64 wrap_max(u64 x, u64 y)
  *  - filter out backward motion
  *  - use the GTOD tick value to create a window to filter crazy TSC values
  */
-static u64 __update_sched_clock(struct sched_clock_data *scd, u64 now)
+static u64 sched_clock_local(struct sched_clock_data *scd)
 {
-	s64 delta = now - scd->tick_raw;
-	u64 clock, min_clock, max_clock;
+	u64 now, clock, old_clock, min_clock, max_clock;
+	s64 delta;
 
+again:
+	now = sched_clock();
+	delta = now - scd->tick_raw;
 	if (unlikely(delta < 0))
 		delta = 0;
 
+	old_clock = scd->clock;
+
 	/*
 	 * scd->clock = clamp(scd->tick_gtod + delta,
 	 *		      max(scd->tick_gtod, scd->clock),
@@ -124,84 +121,73 @@ static u64 __update_sched_clock(struct sched_clock_data *scd, u64 now)
 	 */
 
 	clock = scd->tick_gtod + delta;
-	min_clock = wrap_max(scd->tick_gtod, scd->clock);
-	max_clock = wrap_max(scd->clock, scd->tick_gtod + TICK_NSEC);
+	min_clock = wrap_max(scd->tick_gtod, old_clock);
+	max_clock = wrap_max(old_clock, scd->tick_gtod + TICK_NSEC);
 
 	clock = wrap_max(clock, min_clock);
 	clock = wrap_min(clock, max_clock);
 
-	scd->clock = clock;
+	if (cmpxchg64(&scd->clock, old_clock, clock) != old_clock)
+		goto again;
 
-	return scd->clock;
+	return clock;
 }
 
-static void lock_double_clock(struct sched_clock_data *data1,
-				struct sched_clock_data *data2)
+static u64 sched_clock_remote(struct sched_clock_data *scd)
 {
-	if (data1 < data2) {
-		__raw_spin_lock(&data1->lock);
-		__raw_spin_lock(&data2->lock);
+	struct sched_clock_data *my_scd = this_scd();
+	u64 this_clock, remote_clock;
+	u64 *ptr, old_val, val;
+
+	sched_clock_local(my_scd);
+again:
+	this_clock = my_scd->clock;
+	remote_clock = scd->clock;
+
+	/*
+	 * Use the opportunity that we have both locks
+	 * taken to couple the two clocks: we take the
+	 * larger time as the latest time for both
+	 * runqueues. (this creates monotonic movement)
+	 */
+	if (likely((s64)(remote_clock - this_clock) < 0)) {
+		ptr = &scd->clock;
+		old_val = remote_clock;
+		val = this_clock;
 	} else {
-		__raw_spin_lock(&data2->lock);
-		__raw_spin_lock(&data1->lock);
+		/*
+		 * Should be rare, but possible:
+		 */
+		ptr = &my_scd->clock;
+		old_val = this_clock;
+		val = remote_clock;
 	}
+
+	if (cmpxchg64(ptr, old_val, val) != old_val)
+		goto again;
+
+	return val;
 }
 
 u64 sched_clock_cpu(int cpu)
 {
-	u64 now, clock, this_clock, remote_clock;
 	struct sched_clock_data *scd;
+	u64 clock;
+
+	WARN_ON_ONCE(!irqs_disabled());
 
 	if (sched_clock_stable)
 		return sched_clock();
 
-	scd = cpu_sdc(cpu);
-
-	/*
-	 * Normally this is not called in NMI context - but if it is,
-	 * trying to do any locking here is totally lethal.
-	 */
-	if (unlikely(in_nmi()))
-		return scd->clock;
-
 	if (unlikely(!sched_clock_running))
 		return 0ull;
 
-	WARN_ON_ONCE(!irqs_disabled());
-	now = sched_clock();
-
-	if (cpu != raw_smp_processor_id()) {
-		struct sched_clock_data *my_scd = this_scd();
-
-		lock_double_clock(scd, my_scd);
-
-		this_clock = __update_sched_clock(my_scd, now);
-		remote_clock = scd->clock;
-
-		/*
-		 * Use the opportunity that we have both locks
-		 * taken to couple the two clocks: we take the
-		 * larger time as the latest time for both
-		 * runqueues. (this creates monotonic movement)
-		 */
-		if (likely((s64)(remote_clock - this_clock) < 0)) {
-			clock = this_clock;
-			scd->clock = clock;
-		} else {
-			/*
-			 * Should be rare, but possible:
-			 */
-			clock = remote_clock;
-			my_scd->clock = remote_clock;
-		}
-
-		__raw_spin_unlock(&my_scd->lock);
-	} else {
-		__raw_spin_lock(&scd->lock);
-		clock = __update_sched_clock(scd, now);
-	}
+	scd = cpu_sdc(cpu);
 
-	__raw_spin_unlock(&scd->lock);
+	if (cpu != smp_processor_id())
+		clock = sched_clock_remote(scd);
+	else
+		clock = sched_clock_local(scd);
 
 	return clock;
 }
@@ -223,11 +209,9 @@ void sched_clock_tick(void)
 	now_gtod = ktime_to_ns(ktime_get());
 	now = sched_clock();
 
-	__raw_spin_lock(&scd->lock);
 	scd->tick_raw = now;
 	scd->tick_gtod = now_gtod;
-	__update_sched_clock(scd, now);
-	__raw_spin_unlock(&scd->lock);
+	sched_clock_local(scd);
 }
 
 /*
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index cd73738f0d5..4e777b47eed 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -384,10 +384,10 @@ static struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq)
 
 #ifdef CONFIG_SCHED_DEBUG
 int sched_nr_latency_handler(struct ctl_table *table, int write,
-		struct file *filp, void __user *buffer, size_t *lenp,
+		void __user *buffer, size_t *lenp,
 		loff_t *ppos)
 {
-	int ret = proc_dointvec_minmax(table, write, filp, buffer, lenp, ppos);
+	int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
 
 	if (ret || !write)
 		return ret;
@@ -513,6 +513,7 @@ static void update_curr(struct cfs_rq *cfs_rq)
 	if (entity_is_task(curr)) {
 		struct task_struct *curtask = task_of(curr);
 
+		trace_sched_stat_runtime(curtask, delta_exec, curr->vruntime);
 		cpuacct_charge(curtask, delta_exec);
 		account_group_exec_runtime(curtask, delta_exec);
 	}
diff --git a/kernel/signal.c b/kernel/signal.c
index 64c5deeaca5..6705320784f 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -705,7 +705,7 @@ static int prepare_signal(int sig, struct task_struct *p, int from_ancestor_ns)
 
 		if (why) {
 			/*
-			 * The first thread which returns from finish_stop()
+			 * The first thread which returns from do_signal_stop()
 			 * will take ->siglock, notice SIGNAL_CLD_MASK, and
 			 * notify its parent. See get_signal_to_deliver().
 			 */
@@ -971,6 +971,20 @@ specific_send_sig_info(int sig, struct siginfo *info, struct task_struct *t)
 	return send_signal(sig, info, t, 0);
 }
 
+int do_send_sig_info(int sig, struct siginfo *info, struct task_struct *p,
+			bool group)
+{
+	unsigned long flags;
+	int ret = -ESRCH;
+
+	if (lock_task_sighand(p, &flags)) {
+		ret = send_signal(sig, info, p, group);
+		unlock_task_sighand(p, &flags);
+	}
+
+	return ret;
+}
+
 /*
  * Force a signal that the process can't ignore: if necessary
  * we unblock the signal and change any SIG_IGN to SIG_DFL.
@@ -1036,12 +1050,6 @@ void zap_other_threads(struct task_struct *p)
 	}
 }
 
-int __fatal_signal_pending(struct task_struct *tsk)
-{
-	return sigismember(&tsk->pending.signal, SIGKILL);
-}
-EXPORT_SYMBOL(__fatal_signal_pending);
-
 struct sighand_struct *lock_task_sighand(struct task_struct *tsk, unsigned long *flags)
 {
 	struct sighand_struct *sighand;
@@ -1068,18 +1076,10 @@ struct sighand_struct *lock_task_sighand(struct task_struct *tsk, unsigned long
  */
 int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p)
 {
-	unsigned long flags;
-	int ret;
+	int ret = check_kill_permission(sig, info, p);
 
-	ret = check_kill_permission(sig, info, p);
-
-	if (!ret && sig) {
-		ret = -ESRCH;
-		if (lock_task_sighand(p, &flags)) {
-			ret = __group_send_sig_info(sig, info, p);
-			unlock_task_sighand(p, &flags);
-		}
-	}
+	if (!ret && sig)
+		ret = do_send_sig_info(sig, info, p, true);
 
 	return ret;
 }
@@ -1224,15 +1224,9 @@ static int kill_something_info(int sig, struct siginfo *info, pid_t pid)
  * These are for backward compatibility with the rest of the kernel source.
  */
 
-/*
- * The caller must ensure the task can't exit.
- */
 int
 send_sig_info(int sig, struct siginfo *info, struct task_struct *p)
 {
-	int ret;
-	unsigned long flags;
-
 	/*
 	 * Make sure legacy kernel users don't send in bad values
 	 * (normal paths check this in check_kill_permission).
@@ -1240,10 +1234,7 @@ send_sig_info(int sig, struct siginfo *info, struct task_struct *p)
 	if (!valid_signal(sig))
 		return -EINVAL;
 
-	spin_lock_irqsave(&p->sighand->siglock, flags);
-	ret = specific_send_sig_info(sig, info, p);
-	spin_unlock_irqrestore(&p->sighand->siglock, flags);
-	return ret;
+	return do_send_sig_info(sig, info, p, false);
 }
 
 #define __si_special(priv) \
@@ -1383,15 +1374,6 @@ ret:
 }
 
 /*
- * Wake up any threads in the parent blocked in wait* syscalls.
- */
-static inline void __wake_up_parent(struct task_struct *p,
-				    struct task_struct *parent)
-{
-	wake_up_interruptible_sync(&parent->signal->wait_chldexit);
-}
-
-/*
  * Let a parent know about the death of a child.
  * For a stopped/continued status change, use do_notify_parent_cldstop instead.
  *
@@ -1673,29 +1655,6 @@ void ptrace_notify(int exit_code)
 	spin_unlock_irq(&current->sighand->siglock);
 }
 
-static void
-finish_stop(int stop_count)
-{
-	/*
-	 * If there are no other threads in the group, or if there is
-	 * a group stop in progress and we are the last to stop,
-	 * report to the parent.  When ptraced, every thread reports itself.
-	 */
-	if (tracehook_notify_jctl(stop_count == 0, CLD_STOPPED)) {
-		read_lock(&tasklist_lock);
-		do_notify_parent_cldstop(current, CLD_STOPPED);
-		read_unlock(&tasklist_lock);
-	}
-
-	do {
-		schedule();
-	} while (try_to_freeze());
-	/*
-	 * Now we don't run again until continued.
-	 */
-	current->exit_code = 0;
-}
-
 /*
  * This performs the stopping for SIGSTOP and other stop signals.
  * We have to stop all threads in the thread group.
@@ -1705,15 +1664,9 @@ finish_stop(int stop_count)
 static int do_signal_stop(int signr)
 {
 	struct signal_struct *sig = current->signal;
-	int stop_count;
+	int notify;
 
-	if (sig->group_stop_count > 0) {
-		/*
-		 * There is a group stop in progress.  We don't need to
-		 * start another one.
-		 */
-		stop_count = --sig->group_stop_count;
-	} else {
+	if (!sig->group_stop_count) {
 		struct task_struct *t;
 
 		if (!likely(sig->flags & SIGNAL_STOP_DEQUEUED) ||
@@ -1725,7 +1678,7 @@ static int do_signal_stop(int signr)
 		 */
 		sig->group_exit_code = signr;
 
-		stop_count = 0;
+		sig->group_stop_count = 1;
 		for (t = next_thread(current); t != current; t = next_thread(t))
 			/*
 			 * Setting state to TASK_STOPPED for a group
@@ -1734,19 +1687,44 @@ static int do_signal_stop(int signr)
 			 */
 			if (!(t->flags & PF_EXITING) &&
 			    !task_is_stopped_or_traced(t)) {
-				stop_count++;
+				sig->group_stop_count++;
 				signal_wake_up(t, 0);
 			}
-		sig->group_stop_count = stop_count;
 	}
+	/*
+	 * If there are no other threads in the group, or if there is
+	 * a group stop in progress and we are the last to stop, report
+	 * to the parent.  When ptraced, every thread reports itself.
+	 */
+	notify = sig->group_stop_count == 1 ? CLD_STOPPED : 0;
+	notify = tracehook_notify_jctl(notify, CLD_STOPPED);
+	/*
+	 * tracehook_notify_jctl() can drop and reacquire siglock, so
+	 * we keep ->group_stop_count != 0 before the call. If SIGCONT
+	 * or SIGKILL comes in between ->group_stop_count == 0.
+	 */
+	if (sig->group_stop_count) {
+		if (!--sig->group_stop_count)
+			sig->flags = SIGNAL_STOP_STOPPED;
+		current->exit_code = sig->group_exit_code;
+		__set_current_state(TASK_STOPPED);
+	}
+	spin_unlock_irq(&current->sighand->siglock);
 
-	if (stop_count == 0)
-		sig->flags = SIGNAL_STOP_STOPPED;
-	current->exit_code = sig->group_exit_code;
-	__set_current_state(TASK_STOPPED);
+	if (notify) {
+		read_lock(&tasklist_lock);
+		do_notify_parent_cldstop(current, notify);
+		read_unlock(&tasklist_lock);
+	}
+
+	/* Now we don't run again until woken by SIGCONT or SIGKILL */
+	do {
+		schedule();
+	} while (try_to_freeze());
+
+	tracehook_finish_jctl();
+	current->exit_code = 0;
 
-	spin_unlock_irq(&current->sighand->siglock);
-	finish_stop(stop_count);
 	return 1;
 }
 
@@ -1815,14 +1793,15 @@ relock:
 		int why = (signal->flags & SIGNAL_STOP_CONTINUED)
 				? CLD_CONTINUED : CLD_STOPPED;
 		signal->flags &= ~SIGNAL_CLD_MASK;
-		spin_unlock_irq(&sighand->siglock);
 
-		if (unlikely(!tracehook_notify_jctl(1, why)))
-			goto relock;
+		why = tracehook_notify_jctl(why, CLD_CONTINUED);
+		spin_unlock_irq(&sighand->siglock);
 
-		read_lock(&tasklist_lock);
-		do_notify_parent_cldstop(current->group_leader, why);
-		read_unlock(&tasklist_lock);
+		if (why) {
+			read_lock(&tasklist_lock);
+			do_notify_parent_cldstop(current->group_leader, why);
+			read_unlock(&tasklist_lock);
+		}
 		goto relock;
 	}
 
@@ -1987,14 +1966,14 @@ void exit_signals(struct task_struct *tsk)
 	if (unlikely(tsk->signal->group_stop_count) &&
 			!--tsk->signal->group_stop_count) {
 		tsk->signal->flags = SIGNAL_STOP_STOPPED;
-		group_stop = 1;
+		group_stop = tracehook_notify_jctl(CLD_STOPPED, CLD_STOPPED);
 	}
 out:
 	spin_unlock_irq(&tsk->sighand->siglock);
 
-	if (unlikely(group_stop) && tracehook_notify_jctl(1, CLD_STOPPED)) {
+	if (unlikely(group_stop)) {
 		read_lock(&tasklist_lock);
-		do_notify_parent_cldstop(tsk, CLD_STOPPED);
+		do_notify_parent_cldstop(tsk, group_stop);
 		read_unlock(&tasklist_lock);
 	}
 }
@@ -2290,7 +2269,6 @@ static int
 do_send_specific(pid_t tgid, pid_t pid, int sig, struct siginfo *info)
 {
 	struct task_struct *p;
-	unsigned long flags;
 	int error = -ESRCH;
 
 	rcu_read_lock();
@@ -2300,14 +2278,16 @@ do_send_specific(pid_t tgid, pid_t pid, int sig, struct siginfo *info)
 		/*
 		 * The null signal is a permissions and process existence
 		 * probe.  No signal is actually delivered.
-		 *
-		 * If lock_task_sighand() fails we pretend the task dies
-		 * after receiving the signal. The window is tiny, and the
-		 * signal is private anyway.
 		 */
-		if (!error && sig && lock_task_sighand(p, &flags)) {
-			error = specific_send_sig_info(sig, info, p);
-			unlock_task_sighand(p, &flags);
+		if (!error && sig) {
+			error = do_send_sig_info(sig, info, p, false);
+			/*
+			 * If lock_task_sighand() failed we pretend the task
+			 * dies after receiving the signal. The window is tiny,
+			 * and the signal is private anyway.
+			 */
+			if (unlikely(error == -ESRCH))
+				error = 0;
 		}
 	}
 	rcu_read_unlock();
diff --git a/kernel/slow-work.c b/kernel/slow-work.c
index 09d7519557d..0d31135efbf 100644
--- a/kernel/slow-work.c
+++ b/kernel/slow-work.c
@@ -26,10 +26,10 @@ static void slow_work_cull_timeout(unsigned long);
 static void slow_work_oom_timeout(unsigned long);
 
 #ifdef CONFIG_SYSCTL
-static int slow_work_min_threads_sysctl(struct ctl_table *, int, struct file *,
+static int slow_work_min_threads_sysctl(struct ctl_table *, int,
 					void __user *, size_t *, loff_t *);
 
-static int slow_work_max_threads_sysctl(struct ctl_table *, int , struct file *,
+static int slow_work_max_threads_sysctl(struct ctl_table *, int ,
 					void __user *, size_t *, loff_t *);
 #endif
 
@@ -493,10 +493,10 @@ static void slow_work_oom_timeout(unsigned long data)
  * Handle adjustment of the minimum number of threads
  */
 static int slow_work_min_threads_sysctl(struct ctl_table *table, int write,
-					struct file *filp, void __user *buffer,
+					void __user *buffer,
 					size_t *lenp, loff_t *ppos)
 {
-	int ret = proc_dointvec_minmax(table, write, filp, buffer, lenp, ppos);
+	int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
 	int n;
 
 	if (ret == 0) {
@@ -521,10 +521,10 @@ static int slow_work_min_threads_sysctl(struct ctl_table *table, int write,
  * Handle adjustment of the maximum number of threads
  */
 static int slow_work_max_threads_sysctl(struct ctl_table *table, int write,
-					struct file *filp, void __user *buffer,
+					void __user *buffer,
 					size_t *lenp, loff_t *ppos)
 {
-	int ret = proc_dointvec_minmax(table, write, filp, buffer, lenp, ppos);
+	int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
 	int n;
 
 	if (ret == 0) {
diff --git a/kernel/smp.c b/kernel/smp.c
index 8e218500ab1..c9d1c7835c2 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -29,8 +29,7 @@ enum {
 
 struct call_function_data {
 	struct call_single_data	csd;
-	spinlock_t		lock;
-	unsigned int		refs;
+	atomic_t		refs;
 	cpumask_var_t		cpumask;
 };
 
@@ -39,9 +38,7 @@ struct call_single_queue {
 	spinlock_t		lock;
 };
 
-static DEFINE_PER_CPU(struct call_function_data, cfd_data) = {
-	.lock			= __SPIN_LOCK_UNLOCKED(cfd_data.lock),
-};
+static DEFINE_PER_CPU(struct call_function_data, cfd_data);
 
 static int
 hotplug_cfd(struct notifier_block *nfb, unsigned long action, void *hcpu)
@@ -196,25 +193,18 @@ void generic_smp_call_function_interrupt(void)
 	list_for_each_entry_rcu(data, &call_function.queue, csd.list) {
 		int refs;
 
-		spin_lock(&data->lock);
-		if (!cpumask_test_cpu(cpu, data->cpumask)) {
-			spin_unlock(&data->lock);
+		if (!cpumask_test_and_clear_cpu(cpu, data->cpumask))
 			continue;
-		}
-		cpumask_clear_cpu(cpu, data->cpumask);
-		spin_unlock(&data->lock);
 
 		data->csd.func(data->csd.info);
 
-		spin_lock(&data->lock);
-		WARN_ON(data->refs == 0);
-		refs = --data->refs;
+		refs = atomic_dec_return(&data->refs);
+		WARN_ON(refs < 0);
 		if (!refs) {
 			spin_lock(&call_function.lock);
 			list_del_rcu(&data->csd.list);
 			spin_unlock(&call_function.lock);
 		}
-		spin_unlock(&data->lock);
 
 		if (refs)
 			continue;
@@ -357,13 +347,6 @@ void __smp_call_function_single(int cpu, struct call_single_data *data,
 	generic_exec_single(cpu, data, wait);
 }
 
-/* Deprecated: shim for archs using old arch_send_call_function_ipi API. */
-
-#ifndef arch_send_call_function_ipi_mask
-# define arch_send_call_function_ipi_mask(maskp) \
-	 arch_send_call_function_ipi(*(maskp))
-#endif
-
 /**
  * smp_call_function_many(): Run a function on a set of other CPUs.
  * @mask: The set of cpus to run on (only runs on online subset).
@@ -419,23 +402,20 @@ void smp_call_function_many(const struct cpumask *mask,
 	data = &__get_cpu_var(cfd_data);
 	csd_lock(&data->csd);
 
-	spin_lock_irqsave(&data->lock, flags);
 	data->csd.func = func;
 	data->csd.info = info;
 	cpumask_and(data->cpumask, mask, cpu_online_mask);
 	cpumask_clear_cpu(this_cpu, data->cpumask);
-	data->refs = cpumask_weight(data->cpumask);
+	atomic_set(&data->refs, cpumask_weight(data->cpumask));
 
-	spin_lock(&call_function.lock);
+	spin_lock_irqsave(&call_function.lock, flags);
 	/*
 	 * Place entry at the _HEAD_ of the list, so that any cpu still
 	 * observing the entry in generic_smp_call_function_interrupt()
 	 * will not miss any other list entries:
 	 */
 	list_add_rcu(&data->csd.list, &call_function.queue);
-	spin_unlock(&call_function.lock);
-
-	spin_unlock_irqrestore(&data->lock, flags);
+	spin_unlock_irqrestore(&call_function.lock, flags);
 
 	/*
 	 * Make the list addition visible before sending the ipi.
diff --git a/kernel/softlockup.c b/kernel/softlockup.c
index 88796c33083..81324d12eb3 100644
--- a/kernel/softlockup.c
+++ b/kernel/softlockup.c
@@ -90,11 +90,11 @@ void touch_all_softlockup_watchdogs(void)
 EXPORT_SYMBOL(touch_all_softlockup_watchdogs);
 
 int proc_dosoftlockup_thresh(struct ctl_table *table, int write,
-			     struct file *filp, void __user *buffer,
+			     void __user *buffer,
 			     size_t *lenp, loff_t *ppos)
 {
 	touch_all_softlockup_watchdogs();
-	return proc_dointvec_minmax(table, write, filp, buffer, lenp, ppos);
+	return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
 }
 
 /*
diff --git a/kernel/sys.c b/kernel/sys.c
index b3f1097c76f..255475d163e 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -14,7 +14,7 @@
 #include <linux/prctl.h>
 #include <linux/highuid.h>
 #include <linux/fs.h>
-#include <linux/perf_counter.h>
+#include <linux/perf_event.h>
 #include <linux/resource.h>
 #include <linux/kernel.h>
 #include <linux/kexec.h>
@@ -1338,6 +1338,7 @@ static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
 	unsigned long flags;
 	cputime_t utime, stime;
 	struct task_cputime cputime;
+	unsigned long maxrss = 0;
 
 	memset((char *) r, 0, sizeof *r);
 	utime = stime = cputime_zero;
@@ -1346,6 +1347,7 @@ static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
 		utime = task_utime(current);
 		stime = task_stime(current);
 		accumulate_thread_rusage(p, r);
+		maxrss = p->signal->maxrss;
 		goto out;
 	}
 
@@ -1363,6 +1365,7 @@ static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
 			r->ru_majflt = p->signal->cmaj_flt;
 			r->ru_inblock = p->signal->cinblock;
 			r->ru_oublock = p->signal->coublock;
+			maxrss = p->signal->cmaxrss;
 
 			if (who == RUSAGE_CHILDREN)
 				break;
@@ -1377,6 +1380,8 @@ static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
 			r->ru_majflt += p->signal->maj_flt;
 			r->ru_inblock += p->signal->inblock;
 			r->ru_oublock += p->signal->oublock;
+			if (maxrss < p->signal->maxrss)
+				maxrss = p->signal->maxrss;
 			t = p;
 			do {
 				accumulate_thread_rusage(t, r);
@@ -1392,6 +1397,15 @@ static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
 out:
 	cputime_to_timeval(utime, &r->ru_utime);
 	cputime_to_timeval(stime, &r->ru_stime);
+
+	if (who != RUSAGE_CHILDREN) {
+		struct mm_struct *mm = get_task_mm(p);
+		if (mm) {
+			setmax_mm_hiwater_rss(&maxrss, mm);
+			mmput(mm);
+		}
+	}
+	r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
 }
 
 int getrusage(struct task_struct *p, int who, struct rusage __user *ru)
@@ -1511,11 +1525,11 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
 		case PR_SET_TSC:
 			error = SET_TSC_CTL(arg2);
 			break;
-		case PR_TASK_PERF_COUNTERS_DISABLE:
-			error = perf_counter_task_disable();
+		case PR_TASK_PERF_EVENTS_DISABLE:
+			error = perf_event_task_disable();
 			break;
-		case PR_TASK_PERF_COUNTERS_ENABLE:
-			error = perf_counter_task_enable();
+		case PR_TASK_PERF_EVENTS_ENABLE:
+			error = perf_event_task_enable();
 			break;
 		case PR_GET_TIMERSLACK:
 			error = current->timer_slack_ns;
@@ -1528,6 +1542,28 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
 				current->timer_slack_ns = arg2;
 			error = 0;
 			break;
+		case PR_MCE_KILL:
+			if (arg4 | arg5)
+				return -EINVAL;
+			switch (arg2) {
+			case 0:
+				if (arg3 != 0)
+					return -EINVAL;
+				current->flags &= ~PF_MCE_PROCESS;
+				break;
+			case 1:
+				current->flags |= PF_MCE_PROCESS;
+				if (arg3 != 0)
+					current->flags |= PF_MCE_EARLY;
+				else
+					current->flags &= ~PF_MCE_EARLY;
+				break;
+			default:
+				return -EINVAL;
+			}
+			error = 0;
+			break;
+
 		default:
 			error = -EINVAL;
 			break;
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index 68320f6b07b..e06d0b8d195 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -49,6 +49,7 @@ cond_syscall(sys_sendmsg);
 cond_syscall(compat_sys_sendmsg);
 cond_syscall(sys_recvmsg);
 cond_syscall(compat_sys_recvmsg);
+cond_syscall(compat_sys_recvfrom);
 cond_syscall(sys_socketcall);
 cond_syscall(sys_futex);
 cond_syscall(compat_sys_futex);
@@ -177,4 +178,4 @@ cond_syscall(sys_eventfd);
 cond_syscall(sys_eventfd2);
 
 /* performance counters: */
-cond_syscall(sys_perf_counter_open);
+cond_syscall(sys_perf_event_open);
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 1a631ba684a..0d949c51741 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -26,7 +26,6 @@
 #include <linux/proc_fs.h>
 #include <linux/security.h>
 #include <linux/ctype.h>
-#include <linux/utsname.h>
 #include <linux/kmemcheck.h>
 #include <linux/smp_lock.h>
 #include <linux/fs.h>
@@ -50,7 +49,7 @@
 #include <linux/reboot.h>
 #include <linux/ftrace.h>
 #include <linux/slow-work.h>
-#include <linux/perf_counter.h>
+#include <linux/perf_event.h>
 
 #include <asm/uaccess.h>
 #include <asm/processor.h>
@@ -77,6 +76,7 @@ extern int max_threads;
 extern int core_uses_pid;
 extern int suid_dumpable;
 extern char core_pattern[];
+extern unsigned int core_pipe_limit;
 extern int pid_max;
 extern int min_free_kbytes;
 extern int pid_max_min, pid_max_max;
@@ -106,6 +106,9 @@ static int __maybe_unused one = 1;
 static int __maybe_unused two = 2;
 static unsigned long one_ul = 1;
 static int one_hundred = 100;
+#ifdef CONFIG_PRINTK
+static int ten_thousand = 10000;
+#endif
 
 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
@@ -160,9 +163,9 @@ extern int max_lock_depth;
 #endif
 
 #ifdef CONFIG_PROC_SYSCTL
-static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
+static int proc_do_cad_pid(struct ctl_table *table, int write,
 		  void __user *buffer, size_t *lenp, loff_t *ppos);
-static int proc_taint(struct ctl_table *table, int write, struct file *filp,
+static int proc_taint(struct ctl_table *table, int write,
 			       void __user *buffer, size_t *lenp, loff_t *ppos);
 #endif
 
@@ -421,6 +424,14 @@ static struct ctl_table kern_table[] = {
 		.proc_handler	= &proc_dostring,
 		.strategy	= &sysctl_string,
 	},
+	{
+		.ctl_name	= CTL_UNNUMBERED,
+		.procname	= "core_pipe_limit",
+		.data		= &core_pipe_limit,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
 #ifdef CONFIG_PROC_SYSCTL
 	{
 		.procname	= "tainted",
@@ -722,6 +733,17 @@ static struct ctl_table kern_table[] = {
 		.mode		= 0644,
 		.proc_handler	= &proc_dointvec,
 	},
+	{
+		.ctl_name	= CTL_UNNUMBERED,
+		.procname	= "printk_delay",
+		.data		= &printk_delay_msec,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_minmax,
+		.strategy	= &sysctl_intvec,
+		.extra1		= &zero,
+		.extra2		= &ten_thousand,
+	},
 #endif
 	{
 		.ctl_name	= KERN_NGROUPS_MAX,
@@ -964,28 +986,28 @@ static struct ctl_table kern_table[] = {
 		.child		= slow_work_sysctls,
 	},
 #endif
-#ifdef CONFIG_PERF_COUNTERS
+#ifdef CONFIG_PERF_EVENTS
 	{
 		.ctl_name	= CTL_UNNUMBERED,
-		.procname	= "perf_counter_paranoid",
-		.data		= &sysctl_perf_counter_paranoid,
-		.maxlen		= sizeof(sysctl_perf_counter_paranoid),
+		.procname	= "perf_event_paranoid",
+		.data		= &sysctl_perf_event_paranoid,
+		.maxlen		= sizeof(sysctl_perf_event_paranoid),
 		.mode		= 0644,
 		.proc_handler	= &proc_dointvec,
 	},
 	{
 		.ctl_name	= CTL_UNNUMBERED,
-		.procname	= "perf_counter_mlock_kb",
-		.data		= &sysctl_perf_counter_mlock,
-		.maxlen		= sizeof(sysctl_perf_counter_mlock),
+		.procname	= "perf_event_mlock_kb",
+		.data		= &sysctl_perf_event_mlock,
+		.maxlen		= sizeof(sysctl_perf_event_mlock),
 		.mode		= 0644,
 		.proc_handler	= &proc_dointvec,
 	},
 	{
 		.ctl_name	= CTL_UNNUMBERED,
-		.procname	= "perf_counter_max_sample_rate",
-		.data		= &sysctl_perf_counter_sample_rate,
-		.maxlen		= sizeof(sysctl_perf_counter_sample_rate),
+		.procname	= "perf_event_max_sample_rate",
+		.data		= &sysctl_perf_event_sample_rate,
+		.maxlen		= sizeof(sysctl_perf_event_sample_rate),
 		.mode		= 0644,
 		.proc_handler	= &proc_dointvec,
 	},
@@ -1376,6 +1398,31 @@ static struct ctl_table vm_table[] = {
 		.mode		= 0644,
 		.proc_handler	= &scan_unevictable_handler,
 	},
+#ifdef CONFIG_MEMORY_FAILURE
+	{
+		.ctl_name	= CTL_UNNUMBERED,
+		.procname	= "memory_failure_early_kill",
+		.data		= &sysctl_memory_failure_early_kill,
+		.maxlen		= sizeof(sysctl_memory_failure_early_kill),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_minmax,
+		.strategy	= &sysctl_intvec,
+		.extra1		= &zero,
+		.extra2		= &one,
+	},
+	{
+		.ctl_name	= CTL_UNNUMBERED,
+		.procname	= "memory_failure_recovery",
+		.data		= &sysctl_memory_failure_recovery,
+		.maxlen		= sizeof(sysctl_memory_failure_recovery),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_minmax,
+		.strategy	= &sysctl_intvec,
+		.extra1		= &zero,
+		.extra2		= &one,
+	},
+#endif
+
 /*
  * NOTE: do not add new entries to this table unless you have read
  * Documentation/sysctl/ctl_unnumbered.txt
@@ -2204,7 +2251,7 @@ void sysctl_head_put(struct ctl_table_header *head)
 #ifdef CONFIG_PROC_SYSCTL
 
 static int _proc_do_string(void* data, int maxlen, int write,
-			   struct file *filp, void __user *buffer,
+			   void __user *buffer,
 			   size_t *lenp, loff_t *ppos)
 {
 	size_t len;
@@ -2265,7 +2312,6 @@ static int _proc_do_string(void* data, int maxlen, int write,
  * proc_dostring - read a string sysctl
  * @table: the sysctl table
  * @write: %TRUE if this is a write to the sysctl file
- * @filp: the file structure
  * @buffer: the user buffer
  * @lenp: the size of the user buffer
  * @ppos: file position
@@ -2279,10 +2325,10 @@ static int _proc_do_string(void* data, int maxlen, int write,
  *
  * Returns 0 on success.
  */
-int proc_dostring(struct ctl_table *table, int write, struct file *filp,
+int proc_dostring(struct ctl_table *table, int write,
 		  void __user *buffer, size_t *lenp, loff_t *ppos)
 {
-	return _proc_do_string(table->data, table->maxlen, write, filp,
+	return _proc_do_string(table->data, table->maxlen, write,
 			       buffer, lenp, ppos);
 }
 
@@ -2307,7 +2353,7 @@ static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
 }
 
 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
-		  int write, struct file *filp, void __user *buffer,
+		  int write, void __user *buffer,
 		  size_t *lenp, loff_t *ppos,
 		  int (*conv)(int *negp, unsigned long *lvalp, int *valp,
 			      int write, void *data),
@@ -2414,13 +2460,13 @@ static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
 #undef TMPBUFLEN
 }
 
-static int do_proc_dointvec(struct ctl_table *table, int write, struct file *filp,
+static int do_proc_dointvec(struct ctl_table *table, int write,
 		  void __user *buffer, size_t *lenp, loff_t *ppos,
 		  int (*conv)(int *negp, unsigned long *lvalp, int *valp,
 			      int write, void *data),
 		  void *data)
 {
-	return __do_proc_dointvec(table->data, table, write, filp,
+	return __do_proc_dointvec(table->data, table, write,
 			buffer, lenp, ppos, conv, data);
 }
 
@@ -2428,7 +2474,6 @@ static int do_proc_dointvec(struct ctl_table *table, int write, struct file *fil
  * proc_dointvec - read a vector of integers
  * @table: the sysctl table
  * @write: %TRUE if this is a write to the sysctl file
- * @filp: the file structure
  * @buffer: the user buffer
  * @lenp: the size of the user buffer
  * @ppos: file position
@@ -2438,10 +2483,10 @@ static int do_proc_dointvec(struct ctl_table *table, int write, struct file *fil
  *
  * Returns 0 on success.
  */
-int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
+int proc_dointvec(struct ctl_table *table, int write,
 		     void __user *buffer, size_t *lenp, loff_t *ppos)
 {
-    return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
+    return do_proc_dointvec(table,write,buffer,lenp,ppos,
 		    	    NULL,NULL);
 }
 
@@ -2449,7 +2494,7 @@ int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
  * Taint values can only be increased
  * This means we can safely use a temporary.
  */
-static int proc_taint(struct ctl_table *table, int write, struct file *filp,
+static int proc_taint(struct ctl_table *table, int write,
 			       void __user *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct ctl_table t;
@@ -2461,7 +2506,7 @@ static int proc_taint(struct ctl_table *table, int write, struct file *filp,
 
 	t = *table;
 	t.data = &tmptaint;
-	err = proc_doulongvec_minmax(&t, write, filp, buffer, lenp, ppos);
+	err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
 	if (err < 0)
 		return err;
 
@@ -2513,7 +2558,6 @@ static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
  * proc_dointvec_minmax - read a vector of integers with min/max values
  * @table: the sysctl table
  * @write: %TRUE if this is a write to the sysctl file
- * @filp: the file structure
  * @buffer: the user buffer
  * @lenp: the size of the user buffer
  * @ppos: file position
@@ -2526,19 +2570,18 @@ static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
  *
  * Returns 0 on success.
  */
-int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
+int proc_dointvec_minmax(struct ctl_table *table, int write,
 		  void __user *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct do_proc_dointvec_minmax_conv_param param = {
 		.min = (int *) table->extra1,
 		.max = (int *) table->extra2,
 	};
-	return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
+	return do_proc_dointvec(table, write, buffer, lenp, ppos,
 				do_proc_dointvec_minmax_conv, &param);
 }
 
 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
-				     struct file *filp,
 				     void __user *buffer,
 				     size_t *lenp, loff_t *ppos,
 				     unsigned long convmul,
@@ -2643,21 +2686,19 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int
 }
 
 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
-				     struct file *filp,
 				     void __user *buffer,
 				     size_t *lenp, loff_t *ppos,
 				     unsigned long convmul,
 				     unsigned long convdiv)
 {
 	return __do_proc_doulongvec_minmax(table->data, table, write,
-			filp, buffer, lenp, ppos, convmul, convdiv);
+			buffer, lenp, ppos, convmul, convdiv);
 }
 
 /**
  * proc_doulongvec_minmax - read a vector of long integers with min/max values
  * @table: the sysctl table
  * @write: %TRUE if this is a write to the sysctl file
- * @filp: the file structure
  * @buffer: the user buffer
  * @lenp: the size of the user buffer
  * @ppos: file position
@@ -2670,17 +2711,16 @@ static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
  *
  * Returns 0 on success.
  */
-int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
+int proc_doulongvec_minmax(struct ctl_table *table, int write,
 			   void __user *buffer, size_t *lenp, loff_t *ppos)
 {
-    return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
+    return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
 }
 
 /**
  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
  * @table: the sysctl table
  * @write: %TRUE if this is a write to the sysctl file
- * @filp: the file structure
  * @buffer: the user buffer
  * @lenp: the size of the user buffer
  * @ppos: file position
@@ -2695,11 +2735,10 @@ int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp
  * Returns 0 on success.
  */
 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
-				      struct file *filp,
 				      void __user *buffer,
 				      size_t *lenp, loff_t *ppos)
 {
-    return do_proc_doulongvec_minmax(table, write, filp, buffer,
+    return do_proc_doulongvec_minmax(table, write, buffer,
 				     lenp, ppos, HZ, 1000l);
 }
 
@@ -2775,7 +2814,6 @@ static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
  * proc_dointvec_jiffies - read a vector of integers as seconds
  * @table: the sysctl table
  * @write: %TRUE if this is a write to the sysctl file
- * @filp: the file structure
  * @buffer: the user buffer
  * @lenp: the size of the user buffer
  * @ppos: file position
@@ -2787,10 +2825,10 @@ static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
  *
  * Returns 0 on success.
  */
-int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
+int proc_dointvec_jiffies(struct ctl_table *table, int write,
 			  void __user *buffer, size_t *lenp, loff_t *ppos)
 {
-    return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
+    return do_proc_dointvec(table,write,buffer,lenp,ppos,
 		    	    do_proc_dointvec_jiffies_conv,NULL);
 }
 
@@ -2798,7 +2836,6 @@ int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
  * @table: the sysctl table
  * @write: %TRUE if this is a write to the sysctl file
- * @filp: the file structure
  * @buffer: the user buffer
  * @lenp: the size of the user buffer
  * @ppos: pointer to the file position
@@ -2810,10 +2847,10 @@ int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
  *
  * Returns 0 on success.
  */
-int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
+int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
 				 void __user *buffer, size_t *lenp, loff_t *ppos)
 {
-    return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
+    return do_proc_dointvec(table,write,buffer,lenp,ppos,
 		    	    do_proc_dointvec_userhz_jiffies_conv,NULL);
 }
 
@@ -2821,7 +2858,6 @@ int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file
  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
  * @table: the sysctl table
  * @write: %TRUE if this is a write to the sysctl file
- * @filp: the file structure
  * @buffer: the user buffer
  * @lenp: the size of the user buffer
  * @ppos: file position
@@ -2834,14 +2870,14 @@ int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file
  *
  * Returns 0 on success.
  */
-int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
+int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
 			     void __user *buffer, size_t *lenp, loff_t *ppos)
 {
-	return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
+	return do_proc_dointvec(table, write, buffer, lenp, ppos,
 				do_proc_dointvec_ms_jiffies_conv, NULL);
 }
 
-static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
+static int proc_do_cad_pid(struct ctl_table *table, int write,
 			   void __user *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct pid *new_pid;
@@ -2850,7 +2886,7 @@ static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp
 
 	tmp = pid_vnr(cad_pid);
 
-	r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
+	r = __do_proc_dointvec(&tmp, table, write, buffer,
 			       lenp, ppos, NULL, NULL);
 	if (r || !write)
 		return r;
@@ -2865,50 +2901,49 @@ static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp
 
 #else /* CONFIG_PROC_FS */
 
-int proc_dostring(struct ctl_table *table, int write, struct file *filp,
+int proc_dostring(struct ctl_table *table, int write,
 		  void __user *buffer, size_t *lenp, loff_t *ppos)
 {
 	return -ENOSYS;
 }
 
-int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
+int proc_dointvec(struct ctl_table *table, int write,
 		  void __user *buffer, size_t *lenp, loff_t *ppos)
 {
 	return -ENOSYS;
 }
 
-int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
+int proc_dointvec_minmax(struct ctl_table *table, int write,
 		    void __user *buffer, size_t *lenp, loff_t *ppos)
 {
 	return -ENOSYS;
 }
 
-int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
+int proc_dointvec_jiffies(struct ctl_table *table, int write,
 		    void __user *buffer, size_t *lenp, loff_t *ppos)
 {
 	return -ENOSYS;
 }
 
-int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
+int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
 		    void __user *buffer, size_t *lenp, loff_t *ppos)
 {
 	return -ENOSYS;
 }
 
-int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
+int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
 			     void __user *buffer, size_t *lenp, loff_t *ppos)
 {
 	return -ENOSYS;
 }
 
-int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
+int proc_doulongvec_minmax(struct ctl_table *table, int write,
 		    void __user *buffer, size_t *lenp, loff_t *ppos)
 {
 	return -ENOSYS;
 }
 
 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
-				      struct file *filp,
 				      void __user *buffer,
 				      size_t *lenp, loff_t *ppos)
 {
diff --git a/kernel/time.c b/kernel/time.c
index 29511943871..2e2e469a7fe 100644
--- a/kernel/time.c
+++ b/kernel/time.c
@@ -370,13 +370,20 @@ EXPORT_SYMBOL(mktime);
  *	0 <= tv_nsec < NSEC_PER_SEC
  * For negative values only the tv_sec field is negative !
  */
-void set_normalized_timespec(struct timespec *ts, time_t sec, long nsec)
+void set_normalized_timespec(struct timespec *ts, time_t sec, s64 nsec)
 {
 	while (nsec >= NSEC_PER_SEC) {
+		/*
+		 * The following asm() prevents the compiler from
+		 * optimising this loop into a modulo operation. See
+		 * also __iter_div_u64_rem() in include/linux/time.h
+		 */
+		asm("" : "+rm"(nsec));
 		nsec -= NSEC_PER_SEC;
 		++sec;
 	}
 	while (nsec < 0) {
+		asm("" : "+rm"(nsec));
 		nsec += NSEC_PER_SEC;
 		--sec;
 	}
diff --git a/kernel/time/Makefile b/kernel/time/Makefile
index 0b0a6366c9d..ee266620b06 100644
--- a/kernel/time/Makefile
+++ b/kernel/time/Makefile
@@ -1,4 +1,4 @@
-obj-y += timekeeping.o ntp.o clocksource.o jiffies.o timer_list.o timecompare.o
+obj-y += timekeeping.o ntp.o clocksource.o jiffies.o timer_list.o timecompare.o timeconv.o
 
 obj-$(CONFIG_GENERIC_CLOCKEVENTS_BUILD)		+= clockevents.o
 obj-$(CONFIG_GENERIC_CLOCKEVENTS)		+= tick-common.o
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 7466cb81125..5e18c6ab2c6 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -21,7 +21,6 @@
  *
  * TODO WishList:
  *   o Allow clocksource drivers to be unregistered
- *   o get rid of clocksource_jiffies extern
  */
 
 #include <linux/clocksource.h>
@@ -30,6 +29,7 @@
 #include <linux/module.h>
 #include <linux/sched.h> /* for spin_unlock_irq() using preempt_count() m68k */
 #include <linux/tick.h>
+#include <linux/kthread.h>
 
 void timecounter_init(struct timecounter *tc,
 		      const struct cyclecounter *cc,
@@ -107,50 +107,35 @@ u64 timecounter_cyc2time(struct timecounter *tc,
 }
 EXPORT_SYMBOL(timecounter_cyc2time);
 
-/* XXX - Would like a better way for initializing curr_clocksource */
-extern struct clocksource clocksource_jiffies;
-
 /*[Clocksource internal variables]---------
  * curr_clocksource:
- *	currently selected clocksource. Initialized to clocksource_jiffies.
- * next_clocksource:
- *	pending next selected clocksource.
+ *	currently selected clocksource.
  * clocksource_list:
  *	linked list with the registered clocksources
- * clocksource_lock:
- *	protects manipulations to curr_clocksource and next_clocksource
- *	and the clocksource_list
+ * clocksource_mutex:
+ *	protects manipulations to curr_clocksource and the clocksource_list
  * override_name:
  *	Name of the user-specified clocksource.
  */
-static struct clocksource *curr_clocksource = &clocksource_jiffies;
-static struct clocksource *next_clocksource;
-static struct clocksource *clocksource_override;
+static struct clocksource *curr_clocksource;
 static LIST_HEAD(clocksource_list);
-static DEFINE_SPINLOCK(clocksource_lock);
+static DEFINE_MUTEX(clocksource_mutex);
 static char override_name[32];
 static int finished_booting;
 
-/* clocksource_done_booting - Called near the end of core bootup
- *
- * Hack to avoid lots of clocksource churn at boot time.
- * We use fs_initcall because we want this to start before
- * device_initcall but after subsys_initcall.
- */
-static int __init clocksource_done_booting(void)
-{
-	finished_booting = 1;
-	return 0;
-}
-fs_initcall(clocksource_done_booting);
-
 #ifdef CONFIG_CLOCKSOURCE_WATCHDOG
+static void clocksource_watchdog_work(struct work_struct *work);
+
 static LIST_HEAD(watchdog_list);
 static struct clocksource *watchdog;
 static struct timer_list watchdog_timer;
+static DECLARE_WORK(watchdog_work, clocksource_watchdog_work);
 static DEFINE_SPINLOCK(watchdog_lock);
 static cycle_t watchdog_last;
-static unsigned long watchdog_resumed;
+static int watchdog_running;
+
+static int clocksource_watchdog_kthread(void *data);
+static void __clocksource_change_rating(struct clocksource *cs, int rating);
 
 /*
  * Interval: 0.5sec Threshold: 0.0625s
@@ -158,135 +143,249 @@ static unsigned long watchdog_resumed;
 #define WATCHDOG_INTERVAL (HZ >> 1)
 #define WATCHDOG_THRESHOLD (NSEC_PER_SEC >> 4)
 
-static void clocksource_ratewd(struct clocksource *cs, int64_t delta)
+static void clocksource_watchdog_work(struct work_struct *work)
 {
-	if (delta > -WATCHDOG_THRESHOLD && delta < WATCHDOG_THRESHOLD)
-		return;
+	/*
+	 * If kthread_run fails the next watchdog scan over the
+	 * watchdog_list will find the unstable clock again.
+	 */
+	kthread_run(clocksource_watchdog_kthread, NULL, "kwatchdog");
+}
+
+static void __clocksource_unstable(struct clocksource *cs)
+{
+	cs->flags &= ~(CLOCK_SOURCE_VALID_FOR_HRES | CLOCK_SOURCE_WATCHDOG);
+	cs->flags |= CLOCK_SOURCE_UNSTABLE;
+	if (finished_booting)
+		schedule_work(&watchdog_work);
+}
 
+static void clocksource_unstable(struct clocksource *cs, int64_t delta)
+{
 	printk(KERN_WARNING "Clocksource %s unstable (delta = %Ld ns)\n",
 	       cs->name, delta);
-	cs->flags &= ~(CLOCK_SOURCE_VALID_FOR_HRES | CLOCK_SOURCE_WATCHDOG);
-	clocksource_change_rating(cs, 0);
-	list_del(&cs->wd_list);
+	__clocksource_unstable(cs);
+}
+
+/**
+ * clocksource_mark_unstable - mark clocksource unstable via watchdog
+ * @cs:		clocksource to be marked unstable
+ *
+ * This function is called instead of clocksource_change_rating from
+ * cpu hotplug code to avoid a deadlock between the clocksource mutex
+ * and the cpu hotplug mutex. It defers the update of the clocksource
+ * to the watchdog thread.
+ */
+void clocksource_mark_unstable(struct clocksource *cs)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&watchdog_lock, flags);
+	if (!(cs->flags & CLOCK_SOURCE_UNSTABLE)) {
+		if (list_empty(&cs->wd_list))
+			list_add(&cs->wd_list, &watchdog_list);
+		__clocksource_unstable(cs);
+	}
+	spin_unlock_irqrestore(&watchdog_lock, flags);
 }
 
 static void clocksource_watchdog(unsigned long data)
 {
-	struct clocksource *cs, *tmp;
+	struct clocksource *cs;
 	cycle_t csnow, wdnow;
 	int64_t wd_nsec, cs_nsec;
-	int resumed;
+	int next_cpu;
 
 	spin_lock(&watchdog_lock);
-
-	resumed = test_and_clear_bit(0, &watchdog_resumed);
+	if (!watchdog_running)
+		goto out;
 
 	wdnow = watchdog->read(watchdog);
-	wd_nsec = cyc2ns(watchdog, (wdnow - watchdog_last) & watchdog->mask);
+	wd_nsec = clocksource_cyc2ns((wdnow - watchdog_last) & watchdog->mask,
+				     watchdog->mult, watchdog->shift);
 	watchdog_last = wdnow;
 
-	list_for_each_entry_safe(cs, tmp, &watchdog_list, wd_list) {
-		csnow = cs->read(cs);
+	list_for_each_entry(cs, &watchdog_list, wd_list) {
 
-		if (unlikely(resumed)) {
-			cs->wd_last = csnow;
+		/* Clocksource already marked unstable? */
+		if (cs->flags & CLOCK_SOURCE_UNSTABLE) {
+			if (finished_booting)
+				schedule_work(&watchdog_work);
 			continue;
 		}
 
-		/* Initialized ? */
+		csnow = cs->read(cs);
+
+		/* Clocksource initialized ? */
 		if (!(cs->flags & CLOCK_SOURCE_WATCHDOG)) {
-			if ((cs->flags & CLOCK_SOURCE_IS_CONTINUOUS) &&
-			    (watchdog->flags & CLOCK_SOURCE_IS_CONTINUOUS)) {
-				cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES;
-				/*
-				 * We just marked the clocksource as
-				 * highres-capable, notify the rest of the
-				 * system as well so that we transition
-				 * into high-res mode:
-				 */
-				tick_clock_notify();
-			}
 			cs->flags |= CLOCK_SOURCE_WATCHDOG;
 			cs->wd_last = csnow;
-		} else {
-			cs_nsec = cyc2ns(cs, (csnow - cs->wd_last) & cs->mask);
-			cs->wd_last = csnow;
-			/* Check the delta. Might remove from the list ! */
-			clocksource_ratewd(cs, cs_nsec - wd_nsec);
+			continue;
 		}
-	}
 
-	if (!list_empty(&watchdog_list)) {
-		/*
-		 * Cycle through CPUs to check if the CPUs stay
-		 * synchronized to each other.
-		 */
-		int next_cpu = cpumask_next(raw_smp_processor_id(),
-					    cpu_online_mask);
+		/* Check the deviation from the watchdog clocksource. */
+		cs_nsec = clocksource_cyc2ns((csnow - cs->wd_last) &
+					     cs->mask, cs->mult, cs->shift);
+		cs->wd_last = csnow;
+		if (abs(cs_nsec - wd_nsec) > WATCHDOG_THRESHOLD) {
+			clocksource_unstable(cs, cs_nsec - wd_nsec);
+			continue;
+		}
 
-		if (next_cpu >= nr_cpu_ids)
-			next_cpu = cpumask_first(cpu_online_mask);
-		watchdog_timer.expires += WATCHDOG_INTERVAL;
-		add_timer_on(&watchdog_timer, next_cpu);
+		if (!(cs->flags & CLOCK_SOURCE_VALID_FOR_HRES) &&
+		    (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS) &&
+		    (watchdog->flags & CLOCK_SOURCE_IS_CONTINUOUS)) {
+			cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES;
+			/*
+			 * We just marked the clocksource as highres-capable,
+			 * notify the rest of the system as well so that we
+			 * transition into high-res mode:
+			 */
+			tick_clock_notify();
+		}
 	}
+
+	/*
+	 * Cycle through CPUs to check if the CPUs stay synchronized
+	 * to each other.
+	 */
+	next_cpu = cpumask_next(raw_smp_processor_id(), cpu_online_mask);
+	if (next_cpu >= nr_cpu_ids)
+		next_cpu = cpumask_first(cpu_online_mask);
+	watchdog_timer.expires += WATCHDOG_INTERVAL;
+	add_timer_on(&watchdog_timer, next_cpu);
+out:
 	spin_unlock(&watchdog_lock);
 }
+
+static inline void clocksource_start_watchdog(void)
+{
+	if (watchdog_running || !watchdog || list_empty(&watchdog_list))
+		return;
+	init_timer(&watchdog_timer);
+	watchdog_timer.function = clocksource_watchdog;
+	watchdog_last = watchdog->read(watchdog);
+	watchdog_timer.expires = jiffies + WATCHDOG_INTERVAL;
+	add_timer_on(&watchdog_timer, cpumask_first(cpu_online_mask));
+	watchdog_running = 1;
+}
+
+static inline void clocksource_stop_watchdog(void)
+{
+	if (!watchdog_running || (watchdog && !list_empty(&watchdog_list)))
+		return;
+	del_timer(&watchdog_timer);
+	watchdog_running = 0;
+}
+
+static inline void clocksource_reset_watchdog(void)
+{
+	struct clocksource *cs;
+
+	list_for_each_entry(cs, &watchdog_list, wd_list)
+		cs->flags &= ~CLOCK_SOURCE_WATCHDOG;
+}
+
 static void clocksource_resume_watchdog(void)
 {
-	set_bit(0, &watchdog_resumed);
+	unsigned long flags;
+
+	spin_lock_irqsave(&watchdog_lock, flags);
+	clocksource_reset_watchdog();
+	spin_unlock_irqrestore(&watchdog_lock, flags);
 }
 
-static void clocksource_check_watchdog(struct clocksource *cs)
+static void clocksource_enqueue_watchdog(struct clocksource *cs)
 {
-	struct clocksource *cse;
 	unsigned long flags;
 
 	spin_lock_irqsave(&watchdog_lock, flags);
 	if (cs->flags & CLOCK_SOURCE_MUST_VERIFY) {
-		int started = !list_empty(&watchdog_list);
-
+		/* cs is a clocksource to be watched. */
 		list_add(&cs->wd_list, &watchdog_list);
-		if (!started && watchdog) {
-			watchdog_last = watchdog->read(watchdog);
-			watchdog_timer.expires = jiffies + WATCHDOG_INTERVAL;
-			add_timer_on(&watchdog_timer,
-				     cpumask_first(cpu_online_mask));
-		}
+		cs->flags &= ~CLOCK_SOURCE_WATCHDOG;
 	} else {
+		/* cs is a watchdog. */
 		if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS)
 			cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES;
-
+		/* Pick the best watchdog. */
 		if (!watchdog || cs->rating > watchdog->rating) {
-			if (watchdog)
-				del_timer(&watchdog_timer);
 			watchdog = cs;
-			init_timer(&watchdog_timer);
-			watchdog_timer.function = clocksource_watchdog;
-
 			/* Reset watchdog cycles */
-			list_for_each_entry(cse, &watchdog_list, wd_list)
-				cse->flags &= ~CLOCK_SOURCE_WATCHDOG;
-			/* Start if list is not empty */
-			if (!list_empty(&watchdog_list)) {
-				watchdog_last = watchdog->read(watchdog);
-				watchdog_timer.expires =
-					jiffies + WATCHDOG_INTERVAL;
-				add_timer_on(&watchdog_timer,
-					     cpumask_first(cpu_online_mask));
-			}
+			clocksource_reset_watchdog();
+		}
+	}
+	/* Check if the watchdog timer needs to be started. */
+	clocksource_start_watchdog();
+	spin_unlock_irqrestore(&watchdog_lock, flags);
+}
+
+static void clocksource_dequeue_watchdog(struct clocksource *cs)
+{
+	struct clocksource *tmp;
+	unsigned long flags;
+
+	spin_lock_irqsave(&watchdog_lock, flags);
+	if (cs->flags & CLOCK_SOURCE_MUST_VERIFY) {
+		/* cs is a watched clocksource. */
+		list_del_init(&cs->wd_list);
+	} else if (cs == watchdog) {
+		/* Reset watchdog cycles */
+		clocksource_reset_watchdog();
+		/* Current watchdog is removed. Find an alternative. */
+		watchdog = NULL;
+		list_for_each_entry(tmp, &clocksource_list, list) {
+			if (tmp == cs || tmp->flags & CLOCK_SOURCE_MUST_VERIFY)
+				continue;
+			if (!watchdog || tmp->rating > watchdog->rating)
+				watchdog = tmp;
 		}
 	}
+	cs->flags &= ~CLOCK_SOURCE_WATCHDOG;
+	/* Check if the watchdog timer needs to be stopped. */
+	clocksource_stop_watchdog();
 	spin_unlock_irqrestore(&watchdog_lock, flags);
 }
-#else
-static void clocksource_check_watchdog(struct clocksource *cs)
+
+static int clocksource_watchdog_kthread(void *data)
+{
+	struct clocksource *cs, *tmp;
+	unsigned long flags;
+	LIST_HEAD(unstable);
+
+	mutex_lock(&clocksource_mutex);
+	spin_lock_irqsave(&watchdog_lock, flags);
+	list_for_each_entry_safe(cs, tmp, &watchdog_list, wd_list)
+		if (cs->flags & CLOCK_SOURCE_UNSTABLE) {
+			list_del_init(&cs->wd_list);
+			list_add(&cs->wd_list, &unstable);
+		}
+	/* Check if the watchdog timer needs to be stopped. */
+	clocksource_stop_watchdog();
+	spin_unlock_irqrestore(&watchdog_lock, flags);
+
+	/* Needs to be done outside of watchdog lock */
+	list_for_each_entry_safe(cs, tmp, &unstable, wd_list) {
+		list_del_init(&cs->wd_list);
+		__clocksource_change_rating(cs, 0);
+	}
+	mutex_unlock(&clocksource_mutex);
+	return 0;
+}
+
+#else /* CONFIG_CLOCKSOURCE_WATCHDOG */
+
+static void clocksource_enqueue_watchdog(struct clocksource *cs)
 {
 	if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS)
 		cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES;
 }
 
+static inline void clocksource_dequeue_watchdog(struct clocksource *cs) { }
 static inline void clocksource_resume_watchdog(void) { }
-#endif
+static inline int clocksource_watchdog_kthread(void *data) { return 0; }
+
+#endif /* CONFIG_CLOCKSOURCE_WATCHDOG */
 
 /**
  * clocksource_resume - resume the clocksource(s)
@@ -294,18 +393,12 @@ static inline void clocksource_resume_watchdog(void) { }
 void clocksource_resume(void)
 {
 	struct clocksource *cs;
-	unsigned long flags;
 
-	spin_lock_irqsave(&clocksource_lock, flags);
-
-	list_for_each_entry(cs, &clocksource_list, list) {
+	list_for_each_entry(cs, &clocksource_list, list)
 		if (cs->resume)
 			cs->resume();
-	}
 
 	clocksource_resume_watchdog();
-
-	spin_unlock_irqrestore(&clocksource_lock, flags);
 }
 
 /**
@@ -320,75 +413,94 @@ void clocksource_touch_watchdog(void)
 	clocksource_resume_watchdog();
 }
 
+#ifdef CONFIG_GENERIC_TIME
+
 /**
- * clocksource_get_next - Returns the selected clocksource
+ * clocksource_select - Select the best clocksource available
  *
+ * Private function. Must hold clocksource_mutex when called.
+ *
+ * Select the clocksource with the best rating, or the clocksource,
+ * which is selected by userspace override.
  */
-struct clocksource *clocksource_get_next(void)
+static void clocksource_select(void)
 {
-	unsigned long flags;
+	struct clocksource *best, *cs;
 
-	spin_lock_irqsave(&clocksource_lock, flags);
-	if (next_clocksource && finished_booting) {
-		curr_clocksource = next_clocksource;
-		next_clocksource = NULL;
+	if (!finished_booting || list_empty(&clocksource_list))
+		return;
+	/* First clocksource on the list has the best rating. */
+	best = list_first_entry(&clocksource_list, struct clocksource, list);
+	/* Check for the override clocksource. */
+	list_for_each_entry(cs, &clocksource_list, list) {
+		if (strcmp(cs->name, override_name) != 0)
+			continue;
+		/*
+		 * Check to make sure we don't switch to a non-highres
+		 * capable clocksource if the tick code is in oneshot
+		 * mode (highres or nohz)
+		 */
+		if (!(cs->flags & CLOCK_SOURCE_VALID_FOR_HRES) &&
+		    tick_oneshot_mode_active()) {
+			/* Override clocksource cannot be used. */
+			printk(KERN_WARNING "Override clocksource %s is not "
+			       "HRT compatible. Cannot switch while in "
+			       "HRT/NOHZ mode\n", cs->name);
+			override_name[0] = 0;
+		} else
+			/* Override clocksource can be used. */
+			best = cs;
+		break;
+	}
+	if (curr_clocksource != best) {
+		printk(KERN_INFO "Switching to clocksource %s\n", best->name);
+		curr_clocksource = best;
+		timekeeping_notify(curr_clocksource);
 	}
-	spin_unlock_irqrestore(&clocksource_lock, flags);
-
-	return curr_clocksource;
 }
 
-/**
- * select_clocksource - Selects the best registered clocksource.
- *
- * Private function. Must hold clocksource_lock when called.
+#else /* CONFIG_GENERIC_TIME */
+
+static inline void clocksource_select(void) { }
+
+#endif
+
+/*
+ * clocksource_done_booting - Called near the end of core bootup
  *
- * Select the clocksource with the best rating, or the clocksource,
- * which is selected by userspace override.
+ * Hack to avoid lots of clocksource churn at boot time.
+ * We use fs_initcall because we want this to start before
+ * device_initcall but after subsys_initcall.
  */
-static struct clocksource *select_clocksource(void)
+static int __init clocksource_done_booting(void)
 {
-	struct clocksource *next;
-
-	if (list_empty(&clocksource_list))
-		return NULL;
-
-	if (clocksource_override)
-		next = clocksource_override;
-	else
-		next = list_entry(clocksource_list.next, struct clocksource,
-				  list);
+	finished_booting = 1;
 
-	if (next == curr_clocksource)
-		return NULL;
+	/*
+	 * Run the watchdog first to eliminate unstable clock sources
+	 */
+	clocksource_watchdog_kthread(NULL);
 
-	return next;
+	mutex_lock(&clocksource_mutex);
+	clocksource_select();
+	mutex_unlock(&clocksource_mutex);
+	return 0;
 }
+fs_initcall(clocksource_done_booting);
 
 /*
  * Enqueue the clocksource sorted by rating
  */
-static int clocksource_enqueue(struct clocksource *c)
+static void clocksource_enqueue(struct clocksource *cs)
 {
-	struct list_head *tmp, *entry = &clocksource_list;
+	struct list_head *entry = &clocksource_list;
+	struct clocksource *tmp;
 
-	list_for_each(tmp, &clocksource_list) {
-		struct clocksource *cs;
-
-		cs = list_entry(tmp, struct clocksource, list);
-		if (cs == c)
-			return -EBUSY;
+	list_for_each_entry(tmp, &clocksource_list, list)
 		/* Keep track of the place, where to insert */
-		if (cs->rating >= c->rating)
-			entry = tmp;
-	}
-	list_add(&c->list, entry);
-
-	if (strlen(c->name) == strlen(override_name) &&
-	    !strcmp(c->name, override_name))
-		clocksource_override = c;
-
-	return 0;
+		if (tmp->rating >= cs->rating)
+			entry = &tmp->list;
+	list_add(&cs->list, entry);
 }
 
 /**
@@ -397,52 +509,48 @@ static int clocksource_enqueue(struct clocksource *c)
  *
  * Returns -EBUSY if registration fails, zero otherwise.
  */
-int clocksource_register(struct clocksource *c)
+int clocksource_register(struct clocksource *cs)
 {
-	unsigned long flags;
-	int ret;
-
-	spin_lock_irqsave(&clocksource_lock, flags);
-	ret = clocksource_enqueue(c);
-	if (!ret)
-		next_clocksource = select_clocksource();
-	spin_unlock_irqrestore(&clocksource_lock, flags);
-	if (!ret)
-		clocksource_check_watchdog(c);
-	return ret;
+	mutex_lock(&clocksource_mutex);
+	clocksource_enqueue(cs);
+	clocksource_select();
+	clocksource_enqueue_watchdog(cs);
+	mutex_unlock(&clocksource_mutex);
+	return 0;
 }
 EXPORT_SYMBOL(clocksource_register);
 
+static void __clocksource_change_rating(struct clocksource *cs, int rating)
+{
+	list_del(&cs->list);
+	cs->rating = rating;
+	clocksource_enqueue(cs);
+	clocksource_select();
+}
+
 /**
  * clocksource_change_rating - Change the rating of a registered clocksource
- *
  */
 void clocksource_change_rating(struct clocksource *cs, int rating)
 {
-	unsigned long flags;
-
-	spin_lock_irqsave(&clocksource_lock, flags);
-	list_del(&cs->list);
-	cs->rating = rating;
-	clocksource_enqueue(cs);
-	next_clocksource = select_clocksource();
-	spin_unlock_irqrestore(&clocksource_lock, flags);
+	mutex_lock(&clocksource_mutex);
+	__clocksource_change_rating(cs, rating);
+	mutex_unlock(&clocksource_mutex);
 }
+EXPORT_SYMBOL(clocksource_change_rating);
 
 /**
  * clocksource_unregister - remove a registered clocksource
  */
 void clocksource_unregister(struct clocksource *cs)
 {
-	unsigned long flags;
-
-	spin_lock_irqsave(&clocksource_lock, flags);
+	mutex_lock(&clocksource_mutex);
+	clocksource_dequeue_watchdog(cs);
 	list_del(&cs->list);
-	if (clocksource_override == cs)
-		clocksource_override = NULL;
-	next_clocksource = select_clocksource();
-	spin_unlock_irqrestore(&clocksource_lock, flags);
+	clocksource_select();
+	mutex_unlock(&clocksource_mutex);
 }
+EXPORT_SYMBOL(clocksource_unregister);
 
 #ifdef CONFIG_SYSFS
 /**
@@ -458,9 +566,9 @@ sysfs_show_current_clocksources(struct sys_device *dev,
 {
 	ssize_t count = 0;
 
-	spin_lock_irq(&clocksource_lock);
+	mutex_lock(&clocksource_mutex);
 	count = snprintf(buf, PAGE_SIZE, "%s\n", curr_clocksource->name);
-	spin_unlock_irq(&clocksource_lock);
+	mutex_unlock(&clocksource_mutex);
 
 	return count;
 }
@@ -478,9 +586,7 @@ static ssize_t sysfs_override_clocksource(struct sys_device *dev,
 					  struct sysdev_attribute *attr,
 					  const char *buf, size_t count)
 {
-	struct clocksource *ovr = NULL;
 	size_t ret = count;
-	int len;
 
 	/* strings from sysfs write are not 0 terminated! */
 	if (count >= sizeof(override_name))
@@ -490,44 +596,14 @@ static ssize_t sysfs_override_clocksource(struct sys_device *dev,
 	if (buf[count-1] == '\n')
 		count--;
 
-	spin_lock_irq(&clocksource_lock);
+	mutex_lock(&clocksource_mutex);
 
 	if (count > 0)
 		memcpy(override_name, buf, count);
 	override_name[count] = 0;
+	clocksource_select();
 
-	len = strlen(override_name);
-	if (len) {
-		struct clocksource *cs;
-
-		ovr = clocksource_override;
-		/* try to select it: */
-		list_for_each_entry(cs, &clocksource_list, list) {
-			if (strlen(cs->name) == len &&
-			    !strcmp(cs->name, override_name))
-				ovr = cs;
-		}
-	}
-
-	/*
-	 * Check to make sure we don't switch to a non-highres capable
-	 * clocksource if the tick code is in oneshot mode (highres or nohz)
-	 */
-	if (tick_oneshot_mode_active() && ovr &&
-	    !(ovr->flags & CLOCK_SOURCE_VALID_FOR_HRES)) {
-		printk(KERN_WARNING "%s clocksource is not HRT compatible. "
-			"Cannot switch while in HRT/NOHZ mode\n", ovr->name);
-		ovr = NULL;
-		override_name[0] = 0;
-	}
-
-	/* Reselect, when the override name has changed */
-	if (ovr != clocksource_override) {
-		clocksource_override = ovr;
-		next_clocksource = select_clocksource();
-	}
-
-	spin_unlock_irq(&clocksource_lock);
+	mutex_unlock(&clocksource_mutex);
 
 	return ret;
 }
@@ -547,7 +623,7 @@ sysfs_show_available_clocksources(struct sys_device *dev,
 	struct clocksource *src;
 	ssize_t count = 0;
 
-	spin_lock_irq(&clocksource_lock);
+	mutex_lock(&clocksource_mutex);
 	list_for_each_entry(src, &clocksource_list, list) {
 		/*
 		 * Don't show non-HRES clocksource if the tick code is
@@ -559,7 +635,7 @@ sysfs_show_available_clocksources(struct sys_device *dev,
 				  max((ssize_t)PAGE_SIZE - count, (ssize_t)0),
 				  "%s ", src->name);
 	}
-	spin_unlock_irq(&clocksource_lock);
+	mutex_unlock(&clocksource_mutex);
 
 	count += snprintf(buf + count,
 			  max((ssize_t)PAGE_SIZE - count, (ssize_t)0), "\n");
@@ -614,11 +690,10 @@ device_initcall(init_clocksource_sysfs);
  */
 static int __init boot_override_clocksource(char* str)
 {
-	unsigned long flags;
-	spin_lock_irqsave(&clocksource_lock, flags);
+	mutex_lock(&clocksource_mutex);
 	if (str)
 		strlcpy(override_name, str, sizeof(override_name));
-	spin_unlock_irqrestore(&clocksource_lock, flags);
+	mutex_unlock(&clocksource_mutex);
 	return 1;
 }
 
diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c
index c3f6c30816e..5404a845690 100644
--- a/kernel/time/jiffies.c
+++ b/kernel/time/jiffies.c
@@ -61,7 +61,6 @@ struct clocksource clocksource_jiffies = {
 	.read		= jiffies_read,
 	.mask		= 0xffffffff, /*32bits*/
 	.mult		= NSEC_PER_JIFFY << JIFFIES_SHIFT, /* details above */
-	.mult_orig	= NSEC_PER_JIFFY << JIFFIES_SHIFT,
 	.shift		= JIFFIES_SHIFT,
 };
 
@@ -71,3 +70,8 @@ static int __init init_jiffies_clocksource(void)
 }
 
 core_initcall(init_jiffies_clocksource);
+
+struct clocksource * __init __weak clocksource_default_clock(void)
+{
+	return &clocksource_jiffies;
+}
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index 7fc64375ff4..4800f933910 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -194,8 +194,7 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
 	case TIME_OK:
 		break;
 	case TIME_INS:
-		xtime.tv_sec--;
-		wall_to_monotonic.tv_sec++;
+		timekeeping_leap_insert(-1);
 		time_state = TIME_OOP;
 		printk(KERN_NOTICE
 			"Clock: inserting leap second 23:59:60 UTC\n");
@@ -203,9 +202,8 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
 		res = HRTIMER_RESTART;
 		break;
 	case TIME_DEL:
-		xtime.tv_sec++;
+		timekeeping_leap_insert(1);
 		time_tai--;
-		wall_to_monotonic.tv_sec--;
 		time_state = TIME_WAIT;
 		printk(KERN_NOTICE
 			"Clock: deleting leap second 23:59:59 UTC\n");
@@ -219,7 +217,6 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
 			time_state = TIME_OK;
 		break;
 	}
-	update_vsyscall(&xtime, clock);
 
 	write_sequnlock(&xtime_lock);
 
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index e0f59a21c06..89aed5933ed 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -231,6 +231,13 @@ void tick_nohz_stop_sched_tick(int inidle)
 	if (!inidle && !ts->inidle)
 		goto end;
 
+	/*
+	 * Set ts->inidle unconditionally. Even if the system did not
+	 * switch to NOHZ mode the cpu frequency governers rely on the
+	 * update of the idle time accounting in tick_nohz_start_idle().
+	 */
+	ts->inidle = 1;
+
 	now = tick_nohz_start_idle(ts);
 
 	/*
@@ -248,8 +255,6 @@ void tick_nohz_stop_sched_tick(int inidle)
 	if (unlikely(ts->nohz_mode == NOHZ_MODE_INACTIVE))
 		goto end;
 
-	ts->inidle = 1;
-
 	if (need_resched())
 		goto end;
 
diff --git a/kernel/time/timeconv.c b/kernel/time/timeconv.c
new file mode 100644
index 00000000000..86628e755f3
--- /dev/null
+++ b/kernel/time/timeconv.c
@@ -0,0 +1,127 @@
+/*
+ * Copyright (C) 1993, 1994, 1995, 1996, 1997 Free Software Foundation, Inc.
+ * This file is part of the GNU C Library.
+ * Contributed by Paul Eggert (eggert@twinsun.com).
+ *
+ * The GNU C Library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * The GNU C Library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with the GNU C Library; see the file COPYING.LIB.  If not,
+ * write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+/*
+ * Converts the calendar time to broken-down time representation
+ * Based on code from glibc-2.6
+ *
+ * 2009-7-14:
+ *   Moved from glibc-2.6 to kernel by Zhaolei<zhaolei@cn.fujitsu.com>
+ */
+
+#include <linux/time.h>
+#include <linux/module.h>
+
+/*
+ * Nonzero if YEAR is a leap year (every 4 years,
+ * except every 100th isn't, and every 400th is).
+ */
+static int __isleap(long year)
+{
+	return (year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0);
+}
+
+/* do a mathdiv for long type */
+static long math_div(long a, long b)
+{
+	return a / b - (a % b < 0);
+}
+
+/* How many leap years between y1 and y2, y1 must less or equal to y2 */
+static long leaps_between(long y1, long y2)
+{
+	long leaps1 = math_div(y1 - 1, 4) - math_div(y1 - 1, 100)
+		+ math_div(y1 - 1, 400);
+	long leaps2 = math_div(y2 - 1, 4) - math_div(y2 - 1, 100)
+		+ math_div(y2 - 1, 400);
+	return leaps2 - leaps1;
+}
+
+/* How many days come before each month (0-12). */
+static const unsigned short __mon_yday[2][13] = {
+	/* Normal years. */
+	{0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365},
+	/* Leap years. */
+	{0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366}
+};
+
+#define SECS_PER_HOUR	(60 * 60)
+#define SECS_PER_DAY	(SECS_PER_HOUR * 24)
+
+/**
+ * time_to_tm - converts the calendar time to local broken-down time
+ *
+ * @totalsecs	the number of seconds elapsed since 00:00:00 on January 1, 1970,
+ *		Coordinated Universal Time (UTC).
+ * @offset	offset seconds adding to totalsecs.
+ * @result	pointer to struct tm variable to receive broken-down time
+ */
+void time_to_tm(time_t totalsecs, int offset, struct tm *result)
+{
+	long days, rem, y;
+	const unsigned short *ip;
+
+	days = totalsecs / SECS_PER_DAY;
+	rem = totalsecs % SECS_PER_DAY;
+	rem += offset;
+	while (rem < 0) {
+		rem += SECS_PER_DAY;
+		--days;
+	}
+	while (rem >= SECS_PER_DAY) {
+		rem -= SECS_PER_DAY;
+		++days;
+	}
+
+	result->tm_hour = rem / SECS_PER_HOUR;
+	rem %= SECS_PER_HOUR;
+	result->tm_min = rem / 60;
+	result->tm_sec = rem % 60;
+
+	/* January 1, 1970 was a Thursday. */
+	result->tm_wday = (4 + days) % 7;
+	if (result->tm_wday < 0)
+		result->tm_wday += 7;
+
+	y = 1970;
+
+	while (days < 0 || days >= (__isleap(y) ? 366 : 365)) {
+		/* Guess a corrected year, assuming 365 days per year. */
+		long yg = y + math_div(days, 365);
+
+		/* Adjust DAYS and Y to match the guessed year. */
+		days -= (yg - y) * 365 + leaps_between(y, yg);
+		y = yg;
+	}
+
+	result->tm_year = y - 1900;
+
+	result->tm_yday = days;
+
+	ip = __mon_yday[__isleap(y)];
+	for (y = 11; days < ip[y]; y--)
+		continue;
+	days -= ip[y];
+
+	result->tm_mon = y;
+	result->tm_mday = days + 1;
+}
+EXPORT_SYMBOL(time_to_tm);
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index e8c77d9c633..c3a4e2907ea 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -13,12 +13,123 @@
 #include <linux/percpu.h>
 #include <linux/init.h>
 #include <linux/mm.h>
+#include <linux/sched.h>
 #include <linux/sysdev.h>
 #include <linux/clocksource.h>
 #include <linux/jiffies.h>
 #include <linux/time.h>
 #include <linux/tick.h>
+#include <linux/stop_machine.h>
+
+/* Structure holding internal timekeeping values. */
+struct timekeeper {
+	/* Current clocksource used for timekeeping. */
+	struct clocksource *clock;
+	/* The shift value of the current clocksource. */
+	int	shift;
+
+	/* Number of clock cycles in one NTP interval. */
+	cycle_t cycle_interval;
+	/* Number of clock shifted nano seconds in one NTP interval. */
+	u64	xtime_interval;
+	/* Raw nano seconds accumulated per NTP interval. */
+	u32	raw_interval;
+
+	/* Clock shifted nano seconds remainder not stored in xtime.tv_nsec. */
+	u64	xtime_nsec;
+	/* Difference between accumulated time and NTP time in ntp
+	 * shifted nano seconds. */
+	s64	ntp_error;
+	/* Shift conversion between clock shifted nano seconds and
+	 * ntp shifted nano seconds. */
+	int	ntp_error_shift;
+	/* NTP adjusted clock multiplier */
+	u32	mult;
+};
+
+struct timekeeper timekeeper;
+
+/**
+ * timekeeper_setup_internals - Set up internals to use clocksource clock.
+ *
+ * @clock:		Pointer to clocksource.
+ *
+ * Calculates a fixed cycle/nsec interval for a given clocksource/adjustment
+ * pair and interval request.
+ *
+ * Unless you're the timekeeping code, you should not be using this!
+ */
+static void timekeeper_setup_internals(struct clocksource *clock)
+{
+	cycle_t interval;
+	u64 tmp;
+
+	timekeeper.clock = clock;
+	clock->cycle_last = clock->read(clock);
 
+	/* Do the ns -> cycle conversion first, using original mult */
+	tmp = NTP_INTERVAL_LENGTH;
+	tmp <<= clock->shift;
+	tmp += clock->mult/2;
+	do_div(tmp, clock->mult);
+	if (tmp == 0)
+		tmp = 1;
+
+	interval = (cycle_t) tmp;
+	timekeeper.cycle_interval = interval;
+
+	/* Go back from cycles -> shifted ns */
+	timekeeper.xtime_interval = (u64) interval * clock->mult;
+	timekeeper.raw_interval =
+		((u64) interval * clock->mult) >> clock->shift;
+
+	timekeeper.xtime_nsec = 0;
+	timekeeper.shift = clock->shift;
+
+	timekeeper.ntp_error = 0;
+	timekeeper.ntp_error_shift = NTP_SCALE_SHIFT - clock->shift;
+
+	/*
+	 * The timekeeper keeps its own mult values for the currently
+	 * active clocksource. These value will be adjusted via NTP
+	 * to counteract clock drifting.
+	 */
+	timekeeper.mult = clock->mult;
+}
+
+/* Timekeeper helper functions. */
+static inline s64 timekeeping_get_ns(void)
+{
+	cycle_t cycle_now, cycle_delta;
+	struct clocksource *clock;
+
+	/* read clocksource: */
+	clock = timekeeper.clock;
+	cycle_now = clock->read(clock);
+
+	/* calculate the delta since the last update_wall_time: */
+	cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
+
+	/* return delta convert to nanoseconds using ntp adjusted mult. */
+	return clocksource_cyc2ns(cycle_delta, timekeeper.mult,
+				  timekeeper.shift);
+}
+
+static inline s64 timekeeping_get_ns_raw(void)
+{
+	cycle_t cycle_now, cycle_delta;
+	struct clocksource *clock;
+
+	/* read clocksource: */
+	clock = timekeeper.clock;
+	cycle_now = clock->read(clock);
+
+	/* calculate the delta since the last update_wall_time: */
+	cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
+
+	/* return delta convert to nanoseconds using ntp adjusted mult. */
+	return clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift);
+}
 
 /*
  * This read-write spinlock protects us from races in SMP while
@@ -44,7 +155,12 @@ __cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock);
  */
 struct timespec xtime __attribute__ ((aligned (16)));
 struct timespec wall_to_monotonic __attribute__ ((aligned (16)));
-static unsigned long total_sleep_time;		/* seconds */
+static struct timespec total_sleep_time;
+
+/*
+ * The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock.
+ */
+struct timespec raw_time;
 
 /* flag for if timekeeping is suspended */
 int __read_mostly timekeeping_suspended;
@@ -56,35 +172,44 @@ void update_xtime_cache(u64 nsec)
 	timespec_add_ns(&xtime_cache, nsec);
 }
 
-struct clocksource *clock;
-
+/* must hold xtime_lock */
+void timekeeping_leap_insert(int leapsecond)
+{
+	xtime.tv_sec += leapsecond;
+	wall_to_monotonic.tv_sec -= leapsecond;
+	update_vsyscall(&xtime, timekeeper.clock);
+}
 
 #ifdef CONFIG_GENERIC_TIME
+
 /**
- * clocksource_forward_now - update clock to the current time
+ * timekeeping_forward_now - update clock to the current time
  *
  * Forward the current clock to update its state since the last call to
  * update_wall_time(). This is useful before significant clock changes,
  * as it avoids having to deal with this time offset explicitly.
  */
-static void clocksource_forward_now(void)
+static void timekeeping_forward_now(void)
 {
 	cycle_t cycle_now, cycle_delta;
+	struct clocksource *clock;
 	s64 nsec;
 
-	cycle_now = clocksource_read(clock);
+	clock = timekeeper.clock;
+	cycle_now = clock->read(clock);
 	cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
 	clock->cycle_last = cycle_now;
 
-	nsec = cyc2ns(clock, cycle_delta);
+	nsec = clocksource_cyc2ns(cycle_delta, timekeeper.mult,
+				  timekeeper.shift);
 
 	/* If arch requires, add in gettimeoffset() */
 	nsec += arch_gettimeoffset();
 
 	timespec_add_ns(&xtime, nsec);
 
-	nsec = ((s64)cycle_delta * clock->mult_orig) >> clock->shift;
-	clock->raw_time.tv_nsec += nsec;
+	nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift);
+	timespec_add_ns(&raw_time, nsec);
 }
 
 /**
@@ -95,7 +220,6 @@ static void clocksource_forward_now(void)
  */
 void getnstimeofday(struct timespec *ts)
 {
-	cycle_t cycle_now, cycle_delta;
 	unsigned long seq;
 	s64 nsecs;
 
@@ -105,15 +229,7 @@ void getnstimeofday(struct timespec *ts)
 		seq = read_seqbegin(&xtime_lock);
 
 		*ts = xtime;
-
-		/* read clocksource: */
-		cycle_now = clocksource_read(clock);
-
-		/* calculate the delta since the last update_wall_time: */
-		cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
-
-		/* convert to nanoseconds: */
-		nsecs = cyc2ns(clock, cycle_delta);
+		nsecs = timekeeping_get_ns();
 
 		/* If arch requires, add in gettimeoffset() */
 		nsecs += arch_gettimeoffset();
@@ -125,6 +241,57 @@ void getnstimeofday(struct timespec *ts)
 
 EXPORT_SYMBOL(getnstimeofday);
 
+ktime_t ktime_get(void)
+{
+	unsigned int seq;
+	s64 secs, nsecs;
+
+	WARN_ON(timekeeping_suspended);
+
+	do {
+		seq = read_seqbegin(&xtime_lock);
+		secs = xtime.tv_sec + wall_to_monotonic.tv_sec;
+		nsecs = xtime.tv_nsec + wall_to_monotonic.tv_nsec;
+		nsecs += timekeeping_get_ns();
+
+	} while (read_seqretry(&xtime_lock, seq));
+	/*
+	 * Use ktime_set/ktime_add_ns to create a proper ktime on
+	 * 32-bit architectures without CONFIG_KTIME_SCALAR.
+	 */
+	return ktime_add_ns(ktime_set(secs, 0), nsecs);
+}
+EXPORT_SYMBOL_GPL(ktime_get);
+
+/**
+ * ktime_get_ts - get the monotonic clock in timespec format
+ * @ts:		pointer to timespec variable
+ *
+ * The function calculates the monotonic clock from the realtime
+ * clock and the wall_to_monotonic offset and stores the result
+ * in normalized timespec format in the variable pointed to by @ts.
+ */
+void ktime_get_ts(struct timespec *ts)
+{
+	struct timespec tomono;
+	unsigned int seq;
+	s64 nsecs;
+
+	WARN_ON(timekeeping_suspended);
+
+	do {
+		seq = read_seqbegin(&xtime_lock);
+		*ts = xtime;
+		tomono = wall_to_monotonic;
+		nsecs = timekeeping_get_ns();
+
+	} while (read_seqretry(&xtime_lock, seq));
+
+	set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec,
+				ts->tv_nsec + tomono.tv_nsec + nsecs);
+}
+EXPORT_SYMBOL_GPL(ktime_get_ts);
+
 /**
  * do_gettimeofday - Returns the time of day in a timeval
  * @tv:		pointer to the timeval to be set
@@ -157,7 +324,7 @@ int do_settimeofday(struct timespec *tv)
 
 	write_seqlock_irqsave(&xtime_lock, flags);
 
-	clocksource_forward_now();
+	timekeeping_forward_now();
 
 	ts_delta.tv_sec = tv->tv_sec - xtime.tv_sec;
 	ts_delta.tv_nsec = tv->tv_nsec - xtime.tv_nsec;
@@ -167,10 +334,10 @@ int do_settimeofday(struct timespec *tv)
 
 	update_xtime_cache(0);
 
-	clock->error = 0;
+	timekeeper.ntp_error = 0;
 	ntp_clear();
 
-	update_vsyscall(&xtime, clock);
+	update_vsyscall(&xtime, timekeeper.clock);
 
 	write_sequnlock_irqrestore(&xtime_lock, flags);
 
@@ -187,44 +354,97 @@ EXPORT_SYMBOL(do_settimeofday);
  *
  * Accumulates current time interval and initializes new clocksource
  */
-static void change_clocksource(void)
+static int change_clocksource(void *data)
 {
 	struct clocksource *new, *old;
 
-	new = clocksource_get_next();
+	new = (struct clocksource *) data;
+
+	timekeeping_forward_now();
+	if (!new->enable || new->enable(new) == 0) {
+		old = timekeeper.clock;
+		timekeeper_setup_internals(new);
+		if (old->disable)
+			old->disable(old);
+	}
+	return 0;
+}
 
-	if (clock == new)
+/**
+ * timekeeping_notify - Install a new clock source
+ * @clock:		pointer to the clock source
+ *
+ * This function is called from clocksource.c after a new, better clock
+ * source has been registered. The caller holds the clocksource_mutex.
+ */
+void timekeeping_notify(struct clocksource *clock)
+{
+	if (timekeeper.clock == clock)
 		return;
+	stop_machine(change_clocksource, clock, NULL);
+	tick_clock_notify();
+}
 
-	clocksource_forward_now();
+#else /* GENERIC_TIME */
 
-	if (clocksource_enable(new))
-		return;
+static inline void timekeeping_forward_now(void) { }
 
-	new->raw_time = clock->raw_time;
-	old = clock;
-	clock = new;
-	clocksource_disable(old);
+/**
+ * ktime_get - get the monotonic time in ktime_t format
+ *
+ * returns the time in ktime_t format
+ */
+ktime_t ktime_get(void)
+{
+	struct timespec now;
 
-	clock->cycle_last = 0;
-	clock->cycle_last = clocksource_read(clock);
-	clock->error = 0;
-	clock->xtime_nsec = 0;
-	clocksource_calculate_interval(clock, NTP_INTERVAL_LENGTH);
+	ktime_get_ts(&now);
 
-	tick_clock_notify();
+	return timespec_to_ktime(now);
+}
+EXPORT_SYMBOL_GPL(ktime_get);
 
-	/*
-	 * We're holding xtime lock and waking up klogd would deadlock
-	 * us on enqueue.  So no printing!
-	printk(KERN_INFO "Time: %s clocksource has been installed.\n",
-	       clock->name);
-	 */
+/**
+ * ktime_get_ts - get the monotonic clock in timespec format
+ * @ts:		pointer to timespec variable
+ *
+ * The function calculates the monotonic clock from the realtime
+ * clock and the wall_to_monotonic offset and stores the result
+ * in normalized timespec format in the variable pointed to by @ts.
+ */
+void ktime_get_ts(struct timespec *ts)
+{
+	struct timespec tomono;
+	unsigned long seq;
+
+	do {
+		seq = read_seqbegin(&xtime_lock);
+		getnstimeofday(ts);
+		tomono = wall_to_monotonic;
+
+	} while (read_seqretry(&xtime_lock, seq));
+
+	set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec,
+				ts->tv_nsec + tomono.tv_nsec);
 }
-#else
-static inline void clocksource_forward_now(void) { }
-static inline void change_clocksource(void) { }
-#endif
+EXPORT_SYMBOL_GPL(ktime_get_ts);
+
+#endif /* !GENERIC_TIME */
+
+/**
+ * ktime_get_real - get the real (wall-) time in ktime_t format
+ *
+ * returns the time in ktime_t format
+ */
+ktime_t ktime_get_real(void)
+{
+	struct timespec now;
+
+	getnstimeofday(&now);
+
+	return timespec_to_ktime(now);
+}
+EXPORT_SYMBOL_GPL(ktime_get_real);
 
 /**
  * getrawmonotonic - Returns the raw monotonic time in a timespec
@@ -236,21 +456,11 @@ void getrawmonotonic(struct timespec *ts)
 {
 	unsigned long seq;
 	s64 nsecs;
-	cycle_t cycle_now, cycle_delta;
 
 	do {
 		seq = read_seqbegin(&xtime_lock);
-
-		/* read clocksource: */
-		cycle_now = clocksource_read(clock);
-
-		/* calculate the delta since the last update_wall_time: */
-		cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
-
-		/* convert to nanoseconds: */
-		nsecs = ((s64)cycle_delta * clock->mult_orig) >> clock->shift;
-
-		*ts = clock->raw_time;
+		nsecs = timekeeping_get_ns_raw();
+		*ts = raw_time;
 
 	} while (read_seqretry(&xtime_lock, seq));
 
@@ -270,7 +480,7 @@ int timekeeping_valid_for_hres(void)
 	do {
 		seq = read_seqbegin(&xtime_lock);
 
-		ret = clock->flags & CLOCK_SOURCE_VALID_FOR_HRES;
+		ret = timekeeper.clock->flags & CLOCK_SOURCE_VALID_FOR_HRES;
 
 	} while (read_seqretry(&xtime_lock, seq));
 
@@ -278,17 +488,33 @@ int timekeeping_valid_for_hres(void)
 }
 
 /**
- * read_persistent_clock -  Return time in seconds from the persistent clock.
+ * read_persistent_clock -  Return time from the persistent clock.
  *
  * Weak dummy function for arches that do not yet support it.
- * Returns seconds from epoch using the battery backed persistent clock.
- * Returns zero if unsupported.
+ * Reads the time from the battery backed persistent clock.
+ * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported.
  *
  *  XXX - Do be sure to remove it once all arches implement it.
  */
-unsigned long __attribute__((weak)) read_persistent_clock(void)
+void __attribute__((weak)) read_persistent_clock(struct timespec *ts)
 {
-	return 0;
+	ts->tv_sec = 0;
+	ts->tv_nsec = 0;
+}
+
+/**
+ * read_boot_clock -  Return time of the system start.
+ *
+ * Weak dummy function for arches that do not yet support it.
+ * Function to read the exact time the system has been started.
+ * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported.
+ *
+ *  XXX - Do be sure to remove it once all arches implement it.
+ */
+void __attribute__((weak)) read_boot_clock(struct timespec *ts)
+{
+	ts->tv_sec = 0;
+	ts->tv_nsec = 0;
 }
 
 /*
@@ -296,29 +522,40 @@ unsigned long __attribute__((weak)) read_persistent_clock(void)
  */
 void __init timekeeping_init(void)
 {
+	struct clocksource *clock;
 	unsigned long flags;
-	unsigned long sec = read_persistent_clock();
+	struct timespec now, boot;
+
+	read_persistent_clock(&now);
+	read_boot_clock(&boot);
 
 	write_seqlock_irqsave(&xtime_lock, flags);
 
 	ntp_init();
 
-	clock = clocksource_get_next();
-	clocksource_enable(clock);
-	clocksource_calculate_interval(clock, NTP_INTERVAL_LENGTH);
-	clock->cycle_last = clocksource_read(clock);
-
-	xtime.tv_sec = sec;
-	xtime.tv_nsec = 0;
+	clock = clocksource_default_clock();
+	if (clock->enable)
+		clock->enable(clock);
+	timekeeper_setup_internals(clock);
+
+	xtime.tv_sec = now.tv_sec;
+	xtime.tv_nsec = now.tv_nsec;
+	raw_time.tv_sec = 0;
+	raw_time.tv_nsec = 0;
+	if (boot.tv_sec == 0 && boot.tv_nsec == 0) {
+		boot.tv_sec = xtime.tv_sec;
+		boot.tv_nsec = xtime.tv_nsec;
+	}
 	set_normalized_timespec(&wall_to_monotonic,
-		-xtime.tv_sec, -xtime.tv_nsec);
+				-boot.tv_sec, -boot.tv_nsec);
 	update_xtime_cache(0);
-	total_sleep_time = 0;
+	total_sleep_time.tv_sec = 0;
+	total_sleep_time.tv_nsec = 0;
 	write_sequnlock_irqrestore(&xtime_lock, flags);
 }
 
 /* time in seconds when suspend began */
-static unsigned long timekeeping_suspend_time;
+static struct timespec timekeeping_suspend_time;
 
 /**
  * timekeeping_resume - Resumes the generic timekeeping subsystem.
@@ -331,24 +568,24 @@ static unsigned long timekeeping_suspend_time;
 static int timekeeping_resume(struct sys_device *dev)
 {
 	unsigned long flags;
-	unsigned long now = read_persistent_clock();
+	struct timespec ts;
+
+	read_persistent_clock(&ts);
 
 	clocksource_resume();
 
 	write_seqlock_irqsave(&xtime_lock, flags);
 
-	if (now && (now > timekeeping_suspend_time)) {
-		unsigned long sleep_length = now - timekeeping_suspend_time;
-
-		xtime.tv_sec += sleep_length;
-		wall_to_monotonic.tv_sec -= sleep_length;
-		total_sleep_time += sleep_length;
+	if (timespec_compare(&ts, &timekeeping_suspend_time) > 0) {
+		ts = timespec_sub(ts, timekeeping_suspend_time);
+		xtime = timespec_add_safe(xtime, ts);
+		wall_to_monotonic = timespec_sub(wall_to_monotonic, ts);
+		total_sleep_time = timespec_add_safe(total_sleep_time, ts);
 	}
 	update_xtime_cache(0);
 	/* re-base the last cycle value */
-	clock->cycle_last = 0;
-	clock->cycle_last = clocksource_read(clock);
-	clock->error = 0;
+	timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock);
+	timekeeper.ntp_error = 0;
 	timekeeping_suspended = 0;
 	write_sequnlock_irqrestore(&xtime_lock, flags);
 
@@ -366,10 +603,10 @@ static int timekeeping_suspend(struct sys_device *dev, pm_message_t state)
 {
 	unsigned long flags;
 
-	timekeeping_suspend_time = read_persistent_clock();
+	read_persistent_clock(&timekeeping_suspend_time);
 
 	write_seqlock_irqsave(&xtime_lock, flags);
-	clocksource_forward_now();
+	timekeeping_forward_now();
 	timekeeping_suspended = 1;
 	write_sequnlock_irqrestore(&xtime_lock, flags);
 
@@ -404,7 +641,7 @@ device_initcall(timekeeping_init_device);
  * If the error is already larger, we look ahead even further
  * to compensate for late or lost adjustments.
  */
-static __always_inline int clocksource_bigadjust(s64 error, s64 *interval,
+static __always_inline int timekeeping_bigadjust(s64 error, s64 *interval,
 						 s64 *offset)
 {
 	s64 tick_error, i;
@@ -420,7 +657,7 @@ static __always_inline int clocksource_bigadjust(s64 error, s64 *interval,
 	 * here.  This is tuned so that an error of about 1 msec is adjusted
 	 * within about 1 sec (or 2^20 nsec in 2^SHIFT_HZ ticks).
 	 */
-	error2 = clock->error >> (NTP_SCALE_SHIFT + 22 - 2 * SHIFT_HZ);
+	error2 = timekeeper.ntp_error >> (NTP_SCALE_SHIFT + 22 - 2 * SHIFT_HZ);
 	error2 = abs(error2);
 	for (look_ahead = 0; error2 > 0; look_ahead++)
 		error2 >>= 2;
@@ -429,8 +666,8 @@ static __always_inline int clocksource_bigadjust(s64 error, s64 *interval,
 	 * Now calculate the error in (1 << look_ahead) ticks, but first
 	 * remove the single look ahead already included in the error.
 	 */
-	tick_error = tick_length >> (NTP_SCALE_SHIFT - clock->shift + 1);
-	tick_error -= clock->xtime_interval >> 1;
+	tick_error = tick_length >> (timekeeper.ntp_error_shift + 1);
+	tick_error -= timekeeper.xtime_interval >> 1;
 	error = ((error - tick_error) >> look_ahead) + tick_error;
 
 	/* Finally calculate the adjustment shift value.  */
@@ -455,18 +692,18 @@ static __always_inline int clocksource_bigadjust(s64 error, s64 *interval,
  * this is optimized for the most common adjustments of -1,0,1,
  * for other values we can do a bit more work.
  */
-static void clocksource_adjust(s64 offset)
+static void timekeeping_adjust(s64 offset)
 {
-	s64 error, interval = clock->cycle_interval;
+	s64 error, interval = timekeeper.cycle_interval;
 	int adj;
 
-	error = clock->error >> (NTP_SCALE_SHIFT - clock->shift - 1);
+	error = timekeeper.ntp_error >> (timekeeper.ntp_error_shift - 1);
 	if (error > interval) {
 		error >>= 2;
 		if (likely(error <= interval))
 			adj = 1;
 		else
-			adj = clocksource_bigadjust(error, &interval, &offset);
+			adj = timekeeping_bigadjust(error, &interval, &offset);
 	} else if (error < -interval) {
 		error >>= 2;
 		if (likely(error >= -interval)) {
@@ -474,15 +711,15 @@ static void clocksource_adjust(s64 offset)
 			interval = -interval;
 			offset = -offset;
 		} else
-			adj = clocksource_bigadjust(error, &interval, &offset);
+			adj = timekeeping_bigadjust(error, &interval, &offset);
 	} else
 		return;
 
-	clock->mult += adj;
-	clock->xtime_interval += interval;
-	clock->xtime_nsec -= offset;
-	clock->error -= (interval - offset) <<
-			(NTP_SCALE_SHIFT - clock->shift);
+	timekeeper.mult += adj;
+	timekeeper.xtime_interval += interval;
+	timekeeper.xtime_nsec -= offset;
+	timekeeper.ntp_error -= (interval - offset) <<
+				timekeeper.ntp_error_shift;
 }
 
 /**
@@ -492,53 +729,59 @@ static void clocksource_adjust(s64 offset)
  */
 void update_wall_time(void)
 {
+	struct clocksource *clock;
 	cycle_t offset;
+	u64 nsecs;
 
 	/* Make sure we're fully resumed: */
 	if (unlikely(timekeeping_suspended))
 		return;
 
+	clock = timekeeper.clock;
 #ifdef CONFIG_GENERIC_TIME
-	offset = (clocksource_read(clock) - clock->cycle_last) & clock->mask;
+	offset = (clock->read(clock) - clock->cycle_last) & clock->mask;
 #else
-	offset = clock->cycle_interval;
+	offset = timekeeper.cycle_interval;
 #endif
-	clock->xtime_nsec = (s64)xtime.tv_nsec << clock->shift;
+	timekeeper.xtime_nsec = (s64)xtime.tv_nsec << timekeeper.shift;
 
 	/* normally this loop will run just once, however in the
 	 * case of lost or late ticks, it will accumulate correctly.
 	 */
-	while (offset >= clock->cycle_interval) {
+	while (offset >= timekeeper.cycle_interval) {
+		u64 nsecps = (u64)NSEC_PER_SEC << timekeeper.shift;
+
 		/* accumulate one interval */
-		offset -= clock->cycle_interval;
-		clock->cycle_last += clock->cycle_interval;
+		offset -= timekeeper.cycle_interval;
+		clock->cycle_last += timekeeper.cycle_interval;
 
-		clock->xtime_nsec += clock->xtime_interval;
-		if (clock->xtime_nsec >= (u64)NSEC_PER_SEC << clock->shift) {
-			clock->xtime_nsec -= (u64)NSEC_PER_SEC << clock->shift;
+		timekeeper.xtime_nsec += timekeeper.xtime_interval;
+		if (timekeeper.xtime_nsec >= nsecps) {
+			timekeeper.xtime_nsec -= nsecps;
 			xtime.tv_sec++;
 			second_overflow();
 		}
 
-		clock->raw_time.tv_nsec += clock->raw_interval;
-		if (clock->raw_time.tv_nsec >= NSEC_PER_SEC) {
-			clock->raw_time.tv_nsec -= NSEC_PER_SEC;
-			clock->raw_time.tv_sec++;
+		raw_time.tv_nsec += timekeeper.raw_interval;
+		if (raw_time.tv_nsec >= NSEC_PER_SEC) {
+			raw_time.tv_nsec -= NSEC_PER_SEC;
+			raw_time.tv_sec++;
 		}
 
 		/* accumulate error between NTP and clock interval */
-		clock->error += tick_length;
-		clock->error -= clock->xtime_interval << (NTP_SCALE_SHIFT - clock->shift);
+		timekeeper.ntp_error += tick_length;
+		timekeeper.ntp_error -= timekeeper.xtime_interval <<
+					timekeeper.ntp_error_shift;
 	}
 
 	/* correct the clock when NTP error is too big */
-	clocksource_adjust(offset);
+	timekeeping_adjust(offset);
 
 	/*
 	 * Since in the loop above, we accumulate any amount of time
 	 * in xtime_nsec over a second into xtime.tv_sec, its possible for
 	 * xtime_nsec to be fairly small after the loop. Further, if we're
-	 * slightly speeding the clocksource up in clocksource_adjust(),
+	 * slightly speeding the clocksource up in timekeeping_adjust(),
 	 * its possible the required corrective factor to xtime_nsec could
 	 * cause it to underflow.
 	 *
@@ -550,24 +793,25 @@ void update_wall_time(void)
 	 * We'll correct this error next time through this function, when
 	 * xtime_nsec is not as small.
 	 */
-	if (unlikely((s64)clock->xtime_nsec < 0)) {
-		s64 neg = -(s64)clock->xtime_nsec;
-		clock->xtime_nsec = 0;
-		clock->error += neg << (NTP_SCALE_SHIFT - clock->shift);
+	if (unlikely((s64)timekeeper.xtime_nsec < 0)) {
+		s64 neg = -(s64)timekeeper.xtime_nsec;
+		timekeeper.xtime_nsec = 0;
+		timekeeper.ntp_error += neg << timekeeper.ntp_error_shift;
 	}
 
 	/* store full nanoseconds into xtime after rounding it up and
 	 * add the remainder to the error difference.
 	 */
-	xtime.tv_nsec = ((s64)clock->xtime_nsec >> clock->shift) + 1;
-	clock->xtime_nsec -= (s64)xtime.tv_nsec << clock->shift;
-	clock->error += clock->xtime_nsec << (NTP_SCALE_SHIFT - clock->shift);
+	xtime.tv_nsec =	((s64) timekeeper.xtime_nsec >> timekeeper.shift) + 1;
+	timekeeper.xtime_nsec -= (s64) xtime.tv_nsec << timekeeper.shift;
+	timekeeper.ntp_error +=	timekeeper.xtime_nsec <<
+				timekeeper.ntp_error_shift;
 
-	update_xtime_cache(cyc2ns(clock, offset));
+	nsecs = clocksource_cyc2ns(offset, timekeeper.mult, timekeeper.shift);
+	update_xtime_cache(nsecs);
 
 	/* check to see if there is a new clocksource to use */
-	change_clocksource();
-	update_vsyscall(&xtime, clock);
+	update_vsyscall(&xtime, timekeeper.clock);
 }
 
 /**
@@ -583,9 +827,12 @@ void update_wall_time(void)
  */
 void getboottime(struct timespec *ts)
 {
-	set_normalized_timespec(ts,
-		- (wall_to_monotonic.tv_sec + total_sleep_time),
-		- wall_to_monotonic.tv_nsec);
+	struct timespec boottime = {
+		.tv_sec = wall_to_monotonic.tv_sec + total_sleep_time.tv_sec,
+		.tv_nsec = wall_to_monotonic.tv_nsec + total_sleep_time.tv_nsec
+	};
+
+	set_normalized_timespec(ts, -boottime.tv_sec, -boottime.tv_nsec);
 }
 
 /**
@@ -594,7 +841,7 @@ void getboottime(struct timespec *ts)
  */
 void monotonic_to_bootbased(struct timespec *ts)
 {
-	ts->tv_sec += total_sleep_time;
+	*ts = timespec_add_safe(*ts, total_sleep_time);
 }
 
 unsigned long get_seconds(void)
@@ -603,6 +850,10 @@ unsigned long get_seconds(void)
 }
 EXPORT_SYMBOL(get_seconds);
 
+struct timespec __current_kernel_time(void)
+{
+	return xtime_cache;
+}
 
 struct timespec current_kernel_time(void)
 {
@@ -618,3 +869,20 @@ struct timespec current_kernel_time(void)
 	return now;
 }
 EXPORT_SYMBOL(current_kernel_time);
+
+struct timespec get_monotonic_coarse(void)
+{
+	struct timespec now, mono;
+	unsigned long seq;
+
+	do {
+		seq = read_seqbegin(&xtime_lock);
+
+		now = xtime_cache;
+		mono = wall_to_monotonic;
+	} while (read_seqretry(&xtime_lock, seq));
+
+	set_normalized_timespec(&now, now.tv_sec + mono.tv_sec,
+				now.tv_nsec + mono.tv_nsec);
+	return now;
+}
diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c
index fddd69d16e0..1b5b7aa2fdf 100644
--- a/kernel/time/timer_list.c
+++ b/kernel/time/timer_list.c
@@ -275,7 +275,7 @@ static int timer_list_open(struct inode *inode, struct file *filp)
 	return single_open(filp, timer_list_show, NULL);
 }
 
-static struct file_operations timer_list_fops = {
+static const struct file_operations timer_list_fops = {
 	.open		= timer_list_open,
 	.read		= seq_read,
 	.llseek		= seq_lseek,
diff --git a/kernel/time/timer_stats.c b/kernel/time/timer_stats.c
index 4cde8b9c716..ee5681f8d7e 100644
--- a/kernel/time/timer_stats.c
+++ b/kernel/time/timer_stats.c
@@ -395,7 +395,7 @@ static int tstats_open(struct inode *inode, struct file *filp)
 	return single_open(filp, tstats_show, NULL);
 }
 
-static struct file_operations tstats_fops = {
+static const struct file_operations tstats_fops = {
 	.open		= tstats_open,
 	.read		= seq_read,
 	.write		= tstats_write,
diff --git a/kernel/timer.c b/kernel/timer.c
index a3d25f41501..5db5a8d2681 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -37,7 +37,7 @@
 #include <linux/delay.h>
 #include <linux/tick.h>
 #include <linux/kallsyms.h>
-#include <linux/perf_counter.h>
+#include <linux/perf_event.h>
 #include <linux/sched.h>
 
 #include <asm/uaccess.h>
@@ -46,6 +46,9 @@
 #include <asm/timex.h>
 #include <asm/io.h>
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/timer.h>
+
 u64 jiffies_64 __cacheline_aligned_in_smp = INITIAL_JIFFIES;
 
 EXPORT_SYMBOL(jiffies_64);
@@ -72,6 +75,7 @@ struct tvec_base {
 	spinlock_t lock;
 	struct timer_list *running_timer;
 	unsigned long timer_jiffies;
+	unsigned long next_timer;
 	struct tvec_root tv1;
 	struct tvec tv2;
 	struct tvec tv3;
@@ -520,6 +524,25 @@ static inline void debug_timer_activate(struct timer_list *timer) { }
 static inline void debug_timer_deactivate(struct timer_list *timer) { }
 #endif
 
+static inline void debug_init(struct timer_list *timer)
+{
+	debug_timer_init(timer);
+	trace_timer_init(timer);
+}
+
+static inline void
+debug_activate(struct timer_list *timer, unsigned long expires)
+{
+	debug_timer_activate(timer);
+	trace_timer_start(timer, expires);
+}
+
+static inline void debug_deactivate(struct timer_list *timer)
+{
+	debug_timer_deactivate(timer);
+	trace_timer_cancel(timer);
+}
+
 static void __init_timer(struct timer_list *timer,
 			 const char *name,
 			 struct lock_class_key *key)
@@ -548,7 +571,7 @@ void init_timer_key(struct timer_list *timer,
 		    const char *name,
 		    struct lock_class_key *key)
 {
-	debug_timer_init(timer);
+	debug_init(timer);
 	__init_timer(timer, name, key);
 }
 EXPORT_SYMBOL(init_timer_key);
@@ -567,7 +590,7 @@ static inline void detach_timer(struct timer_list *timer,
 {
 	struct list_head *entry = &timer->entry;
 
-	debug_timer_deactivate(timer);
+	debug_deactivate(timer);
 
 	__list_del(entry->prev, entry->next);
 	if (clear_pending)
@@ -622,13 +645,16 @@ __mod_timer(struct timer_list *timer, unsigned long expires,
 
 	if (timer_pending(timer)) {
 		detach_timer(timer, 0);
+		if (timer->expires == base->next_timer &&
+		    !tbase_get_deferrable(timer->base))
+			base->next_timer = base->timer_jiffies;
 		ret = 1;
 	} else {
 		if (pending_only)
 			goto out_unlock;
 	}
 
-	debug_timer_activate(timer);
+	debug_activate(timer, expires);
 
 	new_base = __get_cpu_var(tvec_bases);
 
@@ -663,6 +689,9 @@ __mod_timer(struct timer_list *timer, unsigned long expires,
 	}
 
 	timer->expires = expires;
+	if (time_before(timer->expires, base->next_timer) &&
+	    !tbase_get_deferrable(timer->base))
+		base->next_timer = timer->expires;
 	internal_add_timer(base, timer);
 
 out_unlock:
@@ -780,7 +809,10 @@ void add_timer_on(struct timer_list *timer, int cpu)
 	BUG_ON(timer_pending(timer) || !timer->function);
 	spin_lock_irqsave(&base->lock, flags);
 	timer_set_base(timer, base);
-	debug_timer_activate(timer);
+	debug_activate(timer, timer->expires);
+	if (time_before(timer->expires, base->next_timer) &&
+	    !tbase_get_deferrable(timer->base))
+		base->next_timer = timer->expires;
 	internal_add_timer(base, timer);
 	/*
 	 * Check whether the other CPU is idle and needs to be
@@ -817,6 +849,9 @@ int del_timer(struct timer_list *timer)
 		base = lock_timer_base(timer, &flags);
 		if (timer_pending(timer)) {
 			detach_timer(timer, 1);
+			if (timer->expires == base->next_timer &&
+			    !tbase_get_deferrable(timer->base))
+				base->next_timer = base->timer_jiffies;
 			ret = 1;
 		}
 		spin_unlock_irqrestore(&base->lock, flags);
@@ -850,6 +885,9 @@ int try_to_del_timer_sync(struct timer_list *timer)
 	ret = 0;
 	if (timer_pending(timer)) {
 		detach_timer(timer, 1);
+		if (timer->expires == base->next_timer &&
+		    !tbase_get_deferrable(timer->base))
+			base->next_timer = base->timer_jiffies;
 		ret = 1;
 	}
 out:
@@ -984,7 +1022,9 @@ static inline void __run_timers(struct tvec_base *base)
 				 */
 				lock_map_acquire(&lockdep_map);
 
+				trace_timer_expire_entry(timer);
 				fn(data);
+				trace_timer_expire_exit(timer);
 
 				lock_map_release(&lockdep_map);
 
@@ -1007,8 +1047,8 @@ static inline void __run_timers(struct tvec_base *base)
 #ifdef CONFIG_NO_HZ
 /*
  * Find out when the next timer event is due to happen. This
- * is used on S/390 to stop all activity when a cpus is idle.
- * This functions needs to be called disabled.
+ * is used on S/390 to stop all activity when a CPU is idle.
+ * This function needs to be called with interrupts disabled.
  */
 static unsigned long __next_timer_interrupt(struct tvec_base *base)
 {
@@ -1134,7 +1174,9 @@ unsigned long get_next_timer_interrupt(unsigned long now)
 	unsigned long expires;
 
 	spin_lock(&base->lock);
-	expires = __next_timer_interrupt(base);
+	if (time_before_eq(base->next_timer, base->timer_jiffies))
+		base->next_timer = __next_timer_interrupt(base);
+	expires = base->next_timer;
 	spin_unlock(&base->lock);
 
 	if (time_before_eq(expires, now))
@@ -1169,7 +1211,7 @@ static void run_timer_softirq(struct softirq_action *h)
 {
 	struct tvec_base *base = __get_cpu_var(tvec_bases);
 
-	perf_counter_do_pending();
+	perf_event_do_pending();
 
 	hrtimer_run_pending();
 
@@ -1522,6 +1564,7 @@ static int __cpuinit init_timers_cpu(int cpu)
 		INIT_LIST_HEAD(base->tv1.vec + j);
 
 	base->timer_jiffies = jiffies;
+	base->next_timer = base->timer_jiffies;
 	return 0;
 }
 
@@ -1534,6 +1577,9 @@ static void migrate_timer_list(struct tvec_base *new_base, struct list_head *hea
 		timer = list_first_entry(head, struct timer_list, entry);
 		detach_timer(timer, 0);
 		timer_set_base(timer, new_base);
+		if (time_before(timer->expires, new_base->next_timer) &&
+		    !tbase_get_deferrable(timer->base))
+			new_base->next_timer = timer->expires;
 		internal_add_timer(new_base, timer);
 	}
 }
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index e7163460440..b416512ad17 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -83,7 +83,7 @@ config RING_BUFFER_ALLOW_SWAP
 # This allows those options to appear when no other tracer is selected. But the
 # options do not appear when something else selects it. We need the two options
 # GENERIC_TRACER and TRACING to avoid circular dependencies to accomplish the
-# hidding of the automatic options options.
+# hidding of the automatic options.
 
 config TRACING
 	bool
diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index 844164dca90..26f03ac07c2 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -42,7 +42,6 @@ obj-$(CONFIG_BOOT_TRACER) += trace_boot.o
 obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += trace_functions_graph.o
 obj-$(CONFIG_TRACE_BRANCH_PROFILING) += trace_branch.o
 obj-$(CONFIG_HW_BRANCH_TRACER) += trace_hw_branches.o
-obj-$(CONFIG_POWER_TRACER) += trace_power.o
 obj-$(CONFIG_KMEMTRACE) += kmemtrace.o
 obj-$(CONFIG_WORKQUEUE_TRACER) += trace_workqueue.o
 obj-$(CONFIG_BLK_DEV_IO_TRACE) += blktrace.o
@@ -54,5 +53,6 @@ obj-$(CONFIG_EVENT_TRACING) += trace_export.o
 obj-$(CONFIG_FTRACE_SYSCALLS) += trace_syscalls.o
 obj-$(CONFIG_EVENT_PROFILE) += trace_event_profile.o
 obj-$(CONFIG_EVENT_TRACING) += trace_events_filter.o
+obj-$(CONFIG_EVENT_TRACING) += power-traces.o
 
 libftrace-y := ftrace.o
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 3eb159c277c..d9d6206e0b1 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -856,6 +856,37 @@ static void blk_add_trace_remap(struct request_queue *q, struct bio *bio,
 }
 
 /**
+ * blk_add_trace_rq_remap - Add a trace for a request-remap operation
+ * @q:		queue the io is for
+ * @rq:		the source request
+ * @dev:	target device
+ * @from:	source sector
+ *
+ * Description:
+ *     Device mapper remaps request to other devices.
+ *     Add a trace for that action.
+ *
+ **/
+static void blk_add_trace_rq_remap(struct request_queue *q,
+				   struct request *rq, dev_t dev,
+				   sector_t from)
+{
+	struct blk_trace *bt = q->blk_trace;
+	struct blk_io_trace_remap r;
+
+	if (likely(!bt))
+		return;
+
+	r.device_from = cpu_to_be32(dev);
+	r.device_to   = cpu_to_be32(disk_devt(rq->rq_disk));
+	r.sector_from = cpu_to_be64(from);
+
+	__blk_add_trace(bt, blk_rq_pos(rq), blk_rq_bytes(rq),
+			rq_data_dir(rq), BLK_TA_REMAP, !!rq->errors,
+			sizeof(r), &r);
+}
+
+/**
  * blk_add_driver_data - Add binary message with driver-specific data
  * @q:		queue the io is for
  * @rq:		io request
@@ -922,10 +953,13 @@ static void blk_register_tracepoints(void)
 	WARN_ON(ret);
 	ret = register_trace_block_remap(blk_add_trace_remap);
 	WARN_ON(ret);
+	ret = register_trace_block_rq_remap(blk_add_trace_rq_remap);
+	WARN_ON(ret);
 }
 
 static void blk_unregister_tracepoints(void)
 {
+	unregister_trace_block_rq_remap(blk_add_trace_rq_remap);
 	unregister_trace_block_remap(blk_add_trace_remap);
 	unregister_trace_block_split(blk_add_trace_split);
 	unregister_trace_block_unplug_io(blk_add_trace_unplug_io);
@@ -1657,6 +1691,11 @@ int blk_trace_init_sysfs(struct device *dev)
 	return sysfs_create_group(&dev->kobj, &blk_trace_attr_group);
 }
 
+void blk_trace_remove_sysfs(struct device *dev)
+{
+	sysfs_remove_group(&dev->kobj, &blk_trace_attr_group);
+}
+
 #endif /* CONFIG_BLK_DEV_IO_TRACE */
 
 #ifdef CONFIG_EVENT_TRACING
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index cc615f84751..37ba67e3326 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -225,7 +225,11 @@ static void ftrace_update_pid_func(void)
 	if (ftrace_trace_function == ftrace_stub)
 		return;
 
+#ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
 	func = ftrace_trace_function;
+#else
+	func = __ftrace_trace_function;
+#endif
 
 	if (ftrace_pid_trace) {
 		set_ftrace_pid_function(func);
@@ -1074,14 +1078,9 @@ static void ftrace_replace_code(int enable)
 		failed = __ftrace_replace_code(rec, enable);
 		if (failed) {
 			rec->flags |= FTRACE_FL_FAILED;
-			if ((system_state == SYSTEM_BOOTING) ||
-			    !core_kernel_text(rec->ip)) {
-				ftrace_free_rec(rec);
-				} else {
-				ftrace_bug(failed, rec->ip);
-					/* Stop processing */
-					return;
-				}
+			ftrace_bug(failed, rec->ip);
+			/* Stop processing */
+			return;
 		}
 	} while_for_each_ftrace_rec();
 }
@@ -1520,7 +1519,7 @@ static int t_show(struct seq_file *m, void *v)
 	return 0;
 }
 
-static struct seq_operations show_ftrace_seq_ops = {
+static const struct seq_operations show_ftrace_seq_ops = {
 	.start = t_start,
 	.next = t_next,
 	.stop = t_stop,
@@ -1621,8 +1620,10 @@ ftrace_regex_open(struct inode *inode, struct file *file, int enable)
 		if (!ret) {
 			struct seq_file *m = file->private_data;
 			m->private = iter;
-		} else
+		} else {
+			trace_parser_put(&iter->parser);
 			kfree(iter);
+		}
 	} else
 		file->private_data = iter;
 	mutex_unlock(&ftrace_regex_lock);
@@ -2202,7 +2203,7 @@ ftrace_regex_write(struct file *file, const char __user *ubuf,
 	struct trace_parser *parser;
 	ssize_t ret, read;
 
-	if (!cnt || cnt < 0)
+	if (!cnt)
 		return 0;
 
 	mutex_lock(&ftrace_regex_lock);
@@ -2216,7 +2217,7 @@ ftrace_regex_write(struct file *file, const char __user *ubuf,
 	parser = &iter->parser;
 	read = trace_get_user(parser, ubuf, cnt, ppos);
 
-	if (trace_parser_loaded(parser) &&
+	if (read >= 0 && trace_parser_loaded(parser) &&
 	    !trace_parser_cont(parser)) {
 		ret = ftrace_process_regex(parser->buffer,
 					   parser->idx, enable);
@@ -2414,11 +2415,9 @@ unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
 static void *
 __g_next(struct seq_file *m, loff_t *pos)
 {
-	unsigned long *array = m->private;
-
 	if (*pos >= ftrace_graph_count)
 		return NULL;
-	return &array[*pos];
+	return &ftrace_graph_funcs[*pos];
 }
 
 static void *
@@ -2461,7 +2460,7 @@ static int g_show(struct seq_file *m, void *v)
 	return 0;
 }
 
-static struct seq_operations ftrace_graph_seq_ops = {
+static const struct seq_operations ftrace_graph_seq_ops = {
 	.start = g_start,
 	.next = g_next,
 	.stop = g_stop,
@@ -2482,16 +2481,10 @@ ftrace_graph_open(struct inode *inode, struct file *file)
 		ftrace_graph_count = 0;
 		memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs));
 	}
+	mutex_unlock(&graph_lock);
 
-	if (file->f_mode & FMODE_READ) {
+	if (file->f_mode & FMODE_READ)
 		ret = seq_open(file, &ftrace_graph_seq_ops);
-		if (!ret) {
-			struct seq_file *m = file->private_data;
-			m->private = ftrace_graph_funcs;
-		}
-	} else
-		file->private_data = ftrace_graph_funcs;
-	mutex_unlock(&graph_lock);
 
 	return ret;
 }
@@ -2560,9 +2553,7 @@ ftrace_graph_write(struct file *file, const char __user *ubuf,
 		   size_t cnt, loff_t *ppos)
 {
 	struct trace_parser parser;
-	unsigned long *array;
-	size_t read = 0;
-	ssize_t ret;
+	ssize_t read, ret;
 
 	if (!cnt || cnt < 0)
 		return 0;
@@ -2571,35 +2562,31 @@ ftrace_graph_write(struct file *file, const char __user *ubuf,
 
 	if (ftrace_graph_count >= FTRACE_GRAPH_MAX_FUNCS) {
 		ret = -EBUSY;
-		goto out;
+		goto out_unlock;
 	}
 
-	if (file->f_mode & FMODE_READ) {
-		struct seq_file *m = file->private_data;
-		array = m->private;
-	} else
-		array = file->private_data;
-
 	if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) {
 		ret = -ENOMEM;
-		goto out;
+		goto out_unlock;
 	}
 
 	read = trace_get_user(&parser, ubuf, cnt, ppos);
 
-	if (trace_parser_loaded((&parser))) {
+	if (read >= 0 && trace_parser_loaded((&parser))) {
 		parser.buffer[parser.idx] = 0;
 
 		/* we allow only one expression at a time */
-		ret = ftrace_set_func(array, &ftrace_graph_count,
+		ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count,
 					parser.buffer);
 		if (ret)
-			goto out;
+			goto out_free;
 	}
 
 	ret = read;
- out:
+
+out_free:
 	trace_parser_put(&parser);
+out_unlock:
 	mutex_unlock(&graph_lock);
 
 	return ret;
@@ -2670,19 +2657,17 @@ static int ftrace_convert_nops(struct module *mod,
 }
 
 #ifdef CONFIG_MODULES
-void ftrace_release(void *start, void *end)
+void ftrace_release_mod(struct module *mod)
 {
 	struct dyn_ftrace *rec;
 	struct ftrace_page *pg;
-	unsigned long s = (unsigned long)start;
-	unsigned long e = (unsigned long)end;
 
-	if (ftrace_disabled || !start || start == end)
+	if (ftrace_disabled)
 		return;
 
 	mutex_lock(&ftrace_lock);
 	do_for_each_ftrace_rec(pg, rec) {
-		if ((rec->ip >= s) && (rec->ip < e)) {
+		if (within_module_core(rec->ip, mod)) {
 			/*
 			 * rec->ip is changed in ftrace_free_rec()
 			 * It should not between s and e if record was freed.
@@ -2714,9 +2699,7 @@ static int ftrace_module_notify(struct notifier_block *self,
 				   mod->num_ftrace_callsites);
 		break;
 	case MODULE_STATE_GOING:
-		ftrace_release(mod->ftrace_callsites,
-			       mod->ftrace_callsites +
-			       mod->num_ftrace_callsites);
+		ftrace_release_mod(mod);
 		break;
 	}
 
@@ -3030,7 +3013,7 @@ int unregister_ftrace_function(struct ftrace_ops *ops)
 
 int
 ftrace_enable_sysctl(struct ctl_table *table, int write,
-		     struct file *file, void __user *buffer, size_t *lenp,
+		     void __user *buffer, size_t *lenp,
 		     loff_t *ppos)
 {
 	int ret;
@@ -3040,7 +3023,7 @@ ftrace_enable_sysctl(struct ctl_table *table, int write,
 
 	mutex_lock(&ftrace_lock);
 
-	ret  = proc_dointvec(table, write, file, buffer, lenp, ppos);
+	ret  = proc_dointvec(table, write, buffer, lenp, ppos);
 
 	if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
 		goto out;
diff --git a/kernel/trace/kmemtrace.c b/kernel/trace/kmemtrace.c
index 81b1645c854..a91da69f153 100644
--- a/kernel/trace/kmemtrace.c
+++ b/kernel/trace/kmemtrace.c
@@ -501,7 +501,7 @@ static int __init init_kmem_tracer(void)
 		return 1;
 	}
 
-	if (!register_tracer(&kmem_tracer)) {
+	if (register_tracer(&kmem_tracer) != 0) {
 		pr_warning("Warning: could not register the kmem tracer\n");
 		return 1;
 	}
diff --git a/kernel/trace/power-traces.c b/kernel/trace/power-traces.c
new file mode 100644
index 00000000000..e06c6e3d56a
--- /dev/null
+++ b/kernel/trace/power-traces.c
@@ -0,0 +1,20 @@
+/*
+ * Power trace points
+ *
+ * Copyright (C) 2009 Arjan van de Ven <arjan@linux.intel.com>
+ */
+
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/workqueue.h>
+#include <linux/sched.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/power.h>
+
+EXPORT_TRACEPOINT_SYMBOL_GPL(power_start);
+EXPORT_TRACEPOINT_SYMBOL_GPL(power_end);
+EXPORT_TRACEPOINT_SYMBOL_GPL(power_frequency);
+
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 6eef38923b0..d4ff0197054 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -201,8 +201,6 @@ int tracing_is_on(void)
 }
 EXPORT_SYMBOL_GPL(tracing_is_on);
 
-#include "trace.h"
-
 #define RB_EVNT_HDR_SIZE (offsetof(struct ring_buffer_event, array))
 #define RB_ALIGNMENT		4U
 #define RB_MAX_SMALL_DATA	(RB_ALIGNMENT * RINGBUF_TYPE_DATA_TYPE_LEN_MAX)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 420232a1fbb..c820b0310a1 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -125,13 +125,13 @@ int ftrace_dump_on_oops;
 
 static int tracing_set_tracer(const char *buf);
 
-#define BOOTUP_TRACER_SIZE		100
-static char bootup_tracer_buf[BOOTUP_TRACER_SIZE] __initdata;
+#define MAX_TRACER_SIZE		100
+static char bootup_tracer_buf[MAX_TRACER_SIZE] __initdata;
 static char *default_bootup_tracer;
 
 static int __init set_ftrace(char *str)
 {
-	strncpy(bootup_tracer_buf, str, BOOTUP_TRACER_SIZE);
+	strncpy(bootup_tracer_buf, str, MAX_TRACER_SIZE);
 	default_bootup_tracer = bootup_tracer_buf;
 	/* We are using ftrace early, expand it */
 	ring_buffer_expanded = 1;
@@ -242,13 +242,6 @@ static struct tracer		*trace_types __read_mostly;
 static struct tracer		*current_trace __read_mostly;
 
 /*
- * max_tracer_type_len is used to simplify the allocating of
- * buffers to read userspace tracer names. We keep track of
- * the longest tracer name registered.
- */
-static int			max_tracer_type_len;
-
-/*
  * trace_types_lock is used to protect the trace_types list.
  * This lock is also used to keep user access serialized.
  * Accesses from userspace will grab this lock while userspace
@@ -422,7 +415,7 @@ int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
 
 	/* read the non-space input */
 	while (cnt && !isspace(ch)) {
-		if (parser->idx < parser->size)
+		if (parser->idx < parser->size - 1)
 			parser->buffer[parser->idx++] = ch;
 		else {
 			ret = -EINVAL;
@@ -625,7 +618,6 @@ __releases(kernel_lock)
 __acquires(kernel_lock)
 {
 	struct tracer *t;
-	int len;
 	int ret = 0;
 
 	if (!type->name) {
@@ -633,6 +625,11 @@ __acquires(kernel_lock)
 		return -1;
 	}
 
+	if (strlen(type->name) > MAX_TRACER_SIZE) {
+		pr_info("Tracer has a name longer than %d\n", MAX_TRACER_SIZE);
+		return -1;
+	}
+
 	/*
 	 * When this gets called we hold the BKL which means that
 	 * preemption is disabled. Various trace selftests however
@@ -647,7 +644,7 @@ __acquires(kernel_lock)
 	for (t = trace_types; t; t = t->next) {
 		if (strcmp(type->name, t->name) == 0) {
 			/* already found */
-			pr_info("Trace %s already registered\n",
+			pr_info("Tracer %s already registered\n",
 				type->name);
 			ret = -1;
 			goto out;
@@ -698,9 +695,6 @@ __acquires(kernel_lock)
 
 	type->next = trace_types;
 	trace_types = type;
-	len = strlen(type->name);
-	if (len > max_tracer_type_len)
-		max_tracer_type_len = len;
 
  out:
 	tracing_selftest_running = false;
@@ -709,7 +703,7 @@ __acquires(kernel_lock)
 	if (ret || !default_bootup_tracer)
 		goto out_unlock;
 
-	if (strncmp(default_bootup_tracer, type->name, BOOTUP_TRACER_SIZE))
+	if (strncmp(default_bootup_tracer, type->name, MAX_TRACER_SIZE))
 		goto out_unlock;
 
 	printk(KERN_INFO "Starting tracer '%s'\n", type->name);
@@ -731,14 +725,13 @@ __acquires(kernel_lock)
 void unregister_tracer(struct tracer *type)
 {
 	struct tracer **t;
-	int len;
 
 	mutex_lock(&trace_types_lock);
 	for (t = &trace_types; *t; t = &(*t)->next) {
 		if (*t == type)
 			goto found;
 	}
-	pr_info("Trace %s not registered\n", type->name);
+	pr_info("Tracer %s not registered\n", type->name);
 	goto out;
 
  found:
@@ -751,17 +744,7 @@ void unregister_tracer(struct tracer *type)
 			current_trace->stop(&global_trace);
 		current_trace = &nop_trace;
 	}
-
-	if (strlen(type->name) != max_tracer_type_len)
-		goto out;
-
-	max_tracer_type_len = 0;
-	for (t = &trace_types; *t; t = &(*t)->next) {
-		len = strlen((*t)->name);
-		if (len > max_tracer_type_len)
-			max_tracer_type_len = len;
-	}
- out:
+out:
 	mutex_unlock(&trace_types_lock);
 }
 
@@ -1410,7 +1393,7 @@ int trace_array_vprintk(struct trace_array *tr,
 
 int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
 {
-	return trace_array_printk(&global_trace, ip, fmt, args);
+	return trace_array_vprintk(&global_trace, ip, fmt, args);
 }
 EXPORT_SYMBOL_GPL(trace_vprintk);
 
@@ -1966,7 +1949,7 @@ static int s_show(struct seq_file *m, void *v)
 	return 0;
 }
 
-static struct seq_operations tracer_seq_ops = {
+static const struct seq_operations tracer_seq_ops = {
 	.start		= s_start,
 	.next		= s_next,
 	.stop		= s_stop,
@@ -2001,11 +1984,9 @@ __tracing_open(struct inode *inode, struct file *file)
 	if (current_trace)
 		*iter->trace = *current_trace;
 
-	if (!alloc_cpumask_var(&iter->started, GFP_KERNEL))
+	if (!zalloc_cpumask_var(&iter->started, GFP_KERNEL))
 		goto fail;
 
-	cpumask_clear(iter->started);
-
 	if (current_trace && current_trace->print_max)
 		iter->tr = &max_tr;
 	else
@@ -2180,7 +2161,7 @@ static int t_show(struct seq_file *m, void *v)
 	return 0;
 }
 
-static struct seq_operations show_traces_seq_ops = {
+static const struct seq_operations show_traces_seq_ops = {
 	.start		= t_start,
 	.next		= t_next,
 	.stop		= t_stop,
@@ -2610,7 +2591,7 @@ static ssize_t
 tracing_set_trace_read(struct file *filp, char __user *ubuf,
 		       size_t cnt, loff_t *ppos)
 {
-	char buf[max_tracer_type_len+2];
+	char buf[MAX_TRACER_SIZE+2];
 	int r;
 
 	mutex_lock(&trace_types_lock);
@@ -2760,15 +2741,15 @@ static ssize_t
 tracing_set_trace_write(struct file *filp, const char __user *ubuf,
 			size_t cnt, loff_t *ppos)
 {
-	char buf[max_tracer_type_len+1];
+	char buf[MAX_TRACER_SIZE+1];
 	int i;
 	size_t ret;
 	int err;
 
 	ret = cnt;
 
-	if (cnt > max_tracer_type_len)
-		cnt = max_tracer_type_len;
+	if (cnt > MAX_TRACER_SIZE)
+		cnt = MAX_TRACER_SIZE;
 
 	if (copy_from_user(&buf, ubuf, cnt))
 		return -EFAULT;
@@ -4406,7 +4387,7 @@ __init static int tracer_alloc_buffers(void)
 	if (!alloc_cpumask_var(&tracing_cpumask, GFP_KERNEL))
 		goto out_free_buffer_mask;
 
-	if (!alloc_cpumask_var(&tracing_reader_cpumask, GFP_KERNEL))
+	if (!zalloc_cpumask_var(&tracing_reader_cpumask, GFP_KERNEL))
 		goto out_free_tracing_cpumask;
 
 	/* To save memory, keep the ring buffer size to its minimum */
@@ -4417,7 +4398,6 @@ __init static int tracer_alloc_buffers(void)
 
 	cpumask_copy(tracing_buffer_mask, cpu_possible_mask);
 	cpumask_copy(tracing_cpumask, cpu_all_mask);
-	cpumask_clear(tracing_reader_cpumask);
 
 	/* TODO: make the number of buffers hot pluggable with CPUS */
 	global_trace.buffer = ring_buffer_alloc(ring_buf_size,
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 86bcff94791..405cb850b75 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -11,7 +11,6 @@
 #include <linux/ftrace.h>
 #include <trace/boot.h>
 #include <linux/kmemtrace.h>
-#include <trace/power.h>
 
 #include <linux/trace_seq.h>
 #include <linux/ftrace_event.h>
@@ -37,7 +36,6 @@ enum trace_type {
 	TRACE_HW_BRANCHES,
 	TRACE_KMEM_ALLOC,
 	TRACE_KMEM_FREE,
-	TRACE_POWER,
 	TRACE_BLK,
 
 	__TRACE_LAST_TYPE,
@@ -207,7 +205,6 @@ extern void __ftrace_bad_type(void);
 		IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,	\
 			  TRACE_GRAPH_RET);		\
 		IF_ASSIGN(var, ent, struct hw_branch_entry, TRACE_HW_BRANCHES);\
-		IF_ASSIGN(var, ent, struct trace_power, TRACE_POWER); \
 		IF_ASSIGN(var, ent, struct kmemtrace_alloc_entry,	\
 			  TRACE_KMEM_ALLOC);	\
 		IF_ASSIGN(var, ent, struct kmemtrace_free_entry,	\
diff --git a/kernel/trace/trace_branch.c b/kernel/trace/trace_branch.c
index 7a7a9fd249a..4a194f08f88 100644
--- a/kernel/trace/trace_branch.c
+++ b/kernel/trace/trace_branch.c
@@ -34,6 +34,7 @@ probe_likely_condition(struct ftrace_branch_data *f, int val, int expect)
 	struct trace_array *tr = branch_tracer;
 	struct ring_buffer_event *event;
 	struct trace_branch *entry;
+	struct ring_buffer *buffer;
 	unsigned long flags;
 	int cpu, pc;
 	const char *p;
@@ -54,7 +55,8 @@ probe_likely_condition(struct ftrace_branch_data *f, int val, int expect)
 		goto out;
 
 	pc = preempt_count();
-	event = trace_buffer_lock_reserve(tr, TRACE_BRANCH,
+	buffer = tr->buffer;
+	event = trace_buffer_lock_reserve(buffer, TRACE_BRANCH,
 					  sizeof(*entry), flags, pc);
 	if (!event)
 		goto out;
@@ -74,8 +76,8 @@ probe_likely_condition(struct ftrace_branch_data *f, int val, int expect)
 	entry->line = f->line;
 	entry->correct = val == expect;
 
-	if (!filter_check_discard(call, entry, tr->buffer, event))
-		ring_buffer_unlock_commit(tr->buffer, event);
+	if (!filter_check_discard(call, entry, buffer, event))
+		ring_buffer_unlock_commit(buffer, event);
 
  out:
 	atomic_dec(&tr->data[cpu]->disabled);
diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h
index a431748ddd6..ead3d724599 100644
--- a/kernel/trace/trace_entries.h
+++ b/kernel/trace/trace_entries.h
@@ -330,23 +330,6 @@ FTRACE_ENTRY(hw_branch, hw_branch_entry,
 	F_printk("from: %llx to: %llx", __entry->from, __entry->to)
 );
 
-FTRACE_ENTRY(power, trace_power,
-
-	TRACE_POWER,
-
-	F_STRUCT(
-		__field_struct(	struct power_trace,	state_data	)
-		__field_desc(	s64,	state_data,	stamp		)
-		__field_desc(	s64,	state_data,	end		)
-		__field_desc(	int,	state_data,	type		)
-		__field_desc(	int,	state_data,	state		)
-	),
-
-	F_printk("%llx->%llx type:%u state:%u",
-		 __entry->stamp, __entry->end,
-		 __entry->type, __entry->state)
-);
-
 FTRACE_ENTRY(kmem_alloc, kmemtrace_alloc_entry,
 
 	TRACE_KMEM_ALLOC,
diff --git a/kernel/trace/trace_event_profile.c b/kernel/trace/trace_event_profile.c
index 55a25c933d1..8d5c171cc99 100644
--- a/kernel/trace/trace_event_profile.c
+++ b/kernel/trace/trace_event_profile.c
@@ -8,6 +8,62 @@
 #include <linux/module.h>
 #include "trace.h"
 
+/*
+ * We can't use a size but a type in alloc_percpu()
+ * So let's create a dummy type that matches the desired size
+ */
+typedef struct {char buf[FTRACE_MAX_PROFILE_SIZE];} profile_buf_t;
+
+char		*trace_profile_buf;
+EXPORT_SYMBOL_GPL(trace_profile_buf);
+
+char		*trace_profile_buf_nmi;
+EXPORT_SYMBOL_GPL(trace_profile_buf_nmi);
+
+/* Count the events in use (per event id, not per instance) */
+static int	total_profile_count;
+
+static int ftrace_profile_enable_event(struct ftrace_event_call *event)
+{
+	char *buf;
+	int ret = -ENOMEM;
+
+	if (atomic_inc_return(&event->profile_count))
+		return 0;
+
+	if (!total_profile_count) {
+		buf = (char *)alloc_percpu(profile_buf_t);
+		if (!buf)
+			goto fail_buf;
+
+		rcu_assign_pointer(trace_profile_buf, buf);
+
+		buf = (char *)alloc_percpu(profile_buf_t);
+		if (!buf)
+			goto fail_buf_nmi;
+
+		rcu_assign_pointer(trace_profile_buf_nmi, buf);
+	}
+
+	ret = event->profile_enable();
+	if (!ret) {
+		total_profile_count++;
+		return 0;
+	}
+
+fail_buf_nmi:
+	if (!total_profile_count) {
+		free_percpu(trace_profile_buf_nmi);
+		free_percpu(trace_profile_buf);
+		trace_profile_buf_nmi = NULL;
+		trace_profile_buf = NULL;
+	}
+fail_buf:
+	atomic_dec(&event->profile_count);
+
+	return ret;
+}
+
 int ftrace_profile_enable(int event_id)
 {
 	struct ftrace_event_call *event;
@@ -17,7 +73,7 @@ int ftrace_profile_enable(int event_id)
 	list_for_each_entry(event, &ftrace_events, list) {
 		if (event->id == event_id && event->profile_enable &&
 		    try_module_get(event->mod)) {
-			ret = event->profile_enable(event);
+			ret = ftrace_profile_enable_event(event);
 			break;
 		}
 	}
@@ -26,6 +82,33 @@ int ftrace_profile_enable(int event_id)
 	return ret;
 }
 
+static void ftrace_profile_disable_event(struct ftrace_event_call *event)
+{
+	char *buf, *nmi_buf;
+
+	if (!atomic_add_negative(-1, &event->profile_count))
+		return;
+
+	event->profile_disable();
+
+	if (!--total_profile_count) {
+		buf = trace_profile_buf;
+		rcu_assign_pointer(trace_profile_buf, NULL);
+
+		nmi_buf = trace_profile_buf_nmi;
+		rcu_assign_pointer(trace_profile_buf_nmi, NULL);
+
+		/*
+		 * Ensure every events in profiling have finished before
+		 * releasing the buffers
+		 */
+		synchronize_sched();
+
+		free_percpu(buf);
+		free_percpu(nmi_buf);
+	}
+}
+
 void ftrace_profile_disable(int event_id)
 {
 	struct ftrace_event_call *event;
@@ -33,7 +116,7 @@ void ftrace_profile_disable(int event_id)
 	mutex_lock(&event_mutex);
 	list_for_each_entry(event, &ftrace_events, list) {
 		if (event->id == event_id) {
-			event->profile_disable(event);
+			ftrace_profile_disable_event(event);
 			module_put(event->mod);
 			break;
 		}
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 56c260b83a9..d128f65778e 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -232,10 +232,9 @@ ftrace_event_write(struct file *file, const char __user *ubuf,
 		   size_t cnt, loff_t *ppos)
 {
 	struct trace_parser parser;
-	size_t read = 0;
-	ssize_t ret;
+	ssize_t read, ret;
 
-	if (!cnt || cnt < 0)
+	if (!cnt)
 		return 0;
 
 	ret = tracing_update_buffers();
@@ -247,7 +246,7 @@ ftrace_event_write(struct file *file, const char __user *ubuf,
 
 	read = trace_get_user(&parser, ubuf, cnt, ppos);
 
-	if (trace_parser_loaded((&parser))) {
+	if (read >= 0 && trace_parser_loaded((&parser))) {
 		int set = 1;
 
 		if (*parser.buffer == '!')
@@ -271,42 +270,32 @@ ftrace_event_write(struct file *file, const char __user *ubuf,
 static void *
 t_next(struct seq_file *m, void *v, loff_t *pos)
 {
-	struct list_head *list = m->private;
-	struct ftrace_event_call *call;
+	struct ftrace_event_call *call = v;
 
 	(*pos)++;
 
-	for (;;) {
-		if (list == &ftrace_events)
-			return NULL;
-
-		call = list_entry(list, struct ftrace_event_call, list);
-
+	list_for_each_entry_continue(call, &ftrace_events, list) {
 		/*
 		 * The ftrace subsystem is for showing formats only.
 		 * They can not be enabled or disabled via the event files.
 		 */
 		if (call->regfunc)
-			break;
-
-		list = list->next;
+			return call;
 	}
 
-	m->private = list->next;
-
-	return call;
+	return NULL;
 }
 
 static void *t_start(struct seq_file *m, loff_t *pos)
 {
-	struct ftrace_event_call *call = NULL;
+	struct ftrace_event_call *call;
 	loff_t l;
 
 	mutex_lock(&event_mutex);
 
-	m->private = ftrace_events.next;
+	call = list_entry(&ftrace_events, struct ftrace_event_call, list);
 	for (l = 0; l <= *pos; ) {
-		call = t_next(m, NULL, &l);
+		call = t_next(m, call, &l);
 		if (!call)
 			break;
 	}
@@ -316,37 +305,28 @@ static void *t_start(struct seq_file *m, loff_t *pos)
 static void *
 s_next(struct seq_file *m, void *v, loff_t *pos)
 {
-	struct list_head *list = m->private;
-	struct ftrace_event_call *call;
+	struct ftrace_event_call *call = v;
 
 	(*pos)++;
 
- retry:
-	if (list == &ftrace_events)
-		return NULL;
-
-	call = list_entry(list, struct ftrace_event_call, list);
-
-	if (!call->enabled) {
-		list = list->next;
-		goto retry;
+	list_for_each_entry_continue(call, &ftrace_events, list) {
+		if (call->enabled)
+			return call;
 	}
 
-	m->private = list->next;
-
-	return call;
+	return NULL;
 }
 
 static void *s_start(struct seq_file *m, loff_t *pos)
 {
-	struct ftrace_event_call *call = NULL;
+	struct ftrace_event_call *call;
 	loff_t l;
 
 	mutex_lock(&event_mutex);
 
-	m->private = ftrace_events.next;
+	call = list_entry(&ftrace_events, struct ftrace_event_call, list);
 	for (l = 0; l <= *pos; ) {
-		call = s_next(m, NULL, &l);
+		call = s_next(m, call, &l);
 		if (!call)
 			break;
 	}
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 23245785927..98a6cc5c64e 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -933,8 +933,9 @@ static void postfix_clear(struct filter_parse_state *ps)
 
 	while (!list_empty(&ps->postfix)) {
 		elt = list_first_entry(&ps->postfix, struct postfix_elt, list);
-		kfree(elt->operand);
 		list_del(&elt->list);
+		kfree(elt->operand);
+		kfree(elt);
 	}
 }
 
diff --git a/kernel/trace/trace_hw_branches.c b/kernel/trace/trace_hw_branches.c
index ca7d7c4d0c2..69543a905cd 100644
--- a/kernel/trace/trace_hw_branches.c
+++ b/kernel/trace/trace_hw_branches.c
@@ -155,7 +155,7 @@ static enum print_line_t bts_trace_print_line(struct trace_iterator *iter)
 		    seq_print_ip_sym(seq, it->from, symflags) &&
 		    trace_seq_printf(seq, "\n"))
 			return TRACE_TYPE_HANDLED;
-		return TRACE_TYPE_PARTIAL_LINE;;
+		return TRACE_TYPE_PARTIAL_LINE;
 	}
 	return TRACE_TYPE_UNHANDLED;
 }
@@ -165,6 +165,7 @@ void trace_hw_branch(u64 from, u64 to)
 	struct ftrace_event_call *call = &event_hw_branch;
 	struct trace_array *tr = hw_branch_trace;
 	struct ring_buffer_event *event;
+	struct ring_buffer *buf;
 	struct hw_branch_entry *entry;
 	unsigned long irq1;
 	int cpu;
@@ -180,7 +181,8 @@ void trace_hw_branch(u64 from, u64 to)
 	if (atomic_inc_return(&tr->data[cpu]->disabled) != 1)
 		goto out;
 
-	event = trace_buffer_lock_reserve(tr, TRACE_HW_BRANCHES,
+	buf = tr->buffer;
+	event = trace_buffer_lock_reserve(buf, TRACE_HW_BRANCHES,
 					  sizeof(*entry), 0, 0);
 	if (!event)
 		goto out;
@@ -189,8 +191,8 @@ void trace_hw_branch(u64 from, u64 to)
 	entry->ent.type = TRACE_HW_BRANCHES;
 	entry->from = from;
 	entry->to   = to;
-	if (!filter_check_discard(call, entry, tr->buffer, event))
-		trace_buffer_unlock_commit(tr, event, 0, 0);
+	if (!filter_check_discard(call, entry, buf, event))
+		trace_buffer_unlock_commit(buf, event, 0, 0);
 
  out:
 	atomic_dec(&tr->data[cpu]->disabled);
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index f572f44c6e1..ed17565826b 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -486,16 +486,18 @@ int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
 				hardirq ? 'h' : softirq ? 's' : '.'))
 		return 0;
 
-	if (entry->lock_depth < 0)
-		ret = trace_seq_putc(s, '.');
+	if (entry->preempt_count)
+		ret = trace_seq_printf(s, "%x", entry->preempt_count);
 	else
-		ret = trace_seq_printf(s, "%d", entry->lock_depth);
+		ret = trace_seq_putc(s, '.');
+
 	if (!ret)
 		return 0;
 
-	if (entry->preempt_count)
-		return trace_seq_printf(s, "%x", entry->preempt_count);
-	return trace_seq_putc(s, '.');
+	if (entry->lock_depth < 0)
+		return trace_seq_putc(s, '.');
+
+	return trace_seq_printf(s, "%d", entry->lock_depth);
 }
 
 static int
@@ -883,7 +885,7 @@ static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
 	trace_assign_type(field, iter->ent);
 
 	if (!S)
-		task_state_char(field->prev_state);
+		S = task_state_char(field->prev_state);
 	T = task_state_char(field->next_state);
 	if (!trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
 			      field->prev_pid,
@@ -918,7 +920,7 @@ static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
 	trace_assign_type(field, iter->ent);
 
 	if (!S)
-		task_state_char(field->prev_state);
+		S = task_state_char(field->prev_state);
 	T = task_state_char(field->next_state);
 
 	SEQ_PUT_HEX_FIELD_RET(s, field->prev_pid);
diff --git a/kernel/trace/trace_power.c b/kernel/trace/trace_power.c
deleted file mode 100644
index fe1a00f1445..00000000000
--- a/kernel/trace/trace_power.c
+++ /dev/null
@@ -1,218 +0,0 @@
-/*
- * ring buffer based C-state tracer
- *
- * Arjan van de Ven <arjan@linux.intel.com>
- * Copyright (C) 2008 Intel Corporation
- *
- * Much is borrowed from trace_boot.c which is
- * Copyright (C) 2008 Frederic Weisbecker <fweisbec@gmail.com>
- *
- */
-
-#include <linux/init.h>
-#include <linux/debugfs.h>
-#include <trace/power.h>
-#include <linux/kallsyms.h>
-#include <linux/module.h>
-
-#include "trace.h"
-#include "trace_output.h"
-
-static struct trace_array *power_trace;
-static int __read_mostly trace_power_enabled;
-
-static void probe_power_start(struct power_trace *it, unsigned int type,
-				unsigned int level)
-{
-	if (!trace_power_enabled)
-		return;
-
-	memset(it, 0, sizeof(struct power_trace));
-	it->state = level;
-	it->type = type;
-	it->stamp = ktime_get();
-}
-
-
-static void probe_power_end(struct power_trace *it)
-{
-	struct ftrace_event_call *call = &event_power;
-	struct ring_buffer_event *event;
-	struct ring_buffer *buffer;
-	struct trace_power *entry;
-	struct trace_array_cpu *data;
-	struct trace_array *tr = power_trace;
-
-	if (!trace_power_enabled)
-		return;
-
-	buffer = tr->buffer;
-
-	preempt_disable();
-	it->end = ktime_get();
-	data = tr->data[smp_processor_id()];
-
-	event = trace_buffer_lock_reserve(buffer, TRACE_POWER,
-					  sizeof(*entry), 0, 0);
-	if (!event)
-		goto out;
-	entry	= ring_buffer_event_data(event);
-	entry->state_data = *it;
-	if (!filter_check_discard(call, entry, buffer, event))
-		trace_buffer_unlock_commit(buffer, event, 0, 0);
- out:
-	preempt_enable();
-}
-
-static void probe_power_mark(struct power_trace *it, unsigned int type,
-				unsigned int level)
-{
-	struct ftrace_event_call *call = &event_power;
-	struct ring_buffer_event *event;
-	struct ring_buffer *buffer;
-	struct trace_power *entry;
-	struct trace_array_cpu *data;
-	struct trace_array *tr = power_trace;
-
-	if (!trace_power_enabled)
-		return;
-
-	buffer = tr->buffer;
-
-	memset(it, 0, sizeof(struct power_trace));
-	it->state = level;
-	it->type = type;
-	it->stamp = ktime_get();
-	preempt_disable();
-	it->end = it->stamp;
-	data = tr->data[smp_processor_id()];
-
-	event = trace_buffer_lock_reserve(buffer, TRACE_POWER,
-					  sizeof(*entry), 0, 0);
-	if (!event)
-		goto out;
-	entry	= ring_buffer_event_data(event);
-	entry->state_data = *it;
-	if (!filter_check_discard(call, entry, buffer, event))
-		trace_buffer_unlock_commit(buffer, event, 0, 0);
- out:
-	preempt_enable();
-}
-
-static int tracing_power_register(void)
-{
-	int ret;
-
-	ret = register_trace_power_start(probe_power_start);
-	if (ret) {
-		pr_info("power trace: Couldn't activate tracepoint"
-			" probe to trace_power_start\n");
-		return ret;
-	}
-	ret = register_trace_power_end(probe_power_end);
-	if (ret) {
-		pr_info("power trace: Couldn't activate tracepoint"
-			" probe to trace_power_end\n");
-		goto fail_start;
-	}
-	ret = register_trace_power_mark(probe_power_mark);
-	if (ret) {
-		pr_info("power trace: Couldn't activate tracepoint"
-			" probe to trace_power_mark\n");
-		goto fail_end;
-	}
-	return ret;
-fail_end:
-	unregister_trace_power_end(probe_power_end);
-fail_start:
-	unregister_trace_power_start(probe_power_start);
-	return ret;
-}
-
-static void start_power_trace(struct trace_array *tr)
-{
-	trace_power_enabled = 1;
-}
-
-static void stop_power_trace(struct trace_array *tr)
-{
-	trace_power_enabled = 0;
-}
-
-static void power_trace_reset(struct trace_array *tr)
-{
-	trace_power_enabled = 0;
-	unregister_trace_power_start(probe_power_start);
-	unregister_trace_power_end(probe_power_end);
-	unregister_trace_power_mark(probe_power_mark);
-}
-
-
-static int power_trace_init(struct trace_array *tr)
-{
-	power_trace = tr;
-
-	trace_power_enabled = 1;
-	tracing_power_register();
-
-	tracing_reset_online_cpus(tr);
-	return 0;
-}
-
-static enum print_line_t power_print_line(struct trace_iterator *iter)
-{
-	int ret = 0;
-	struct trace_entry *entry = iter->ent;
-	struct trace_power *field ;
-	struct power_trace *it;
-	struct trace_seq *s = &iter->seq;
-	struct timespec stamp;
-	struct timespec duration;
-
-	trace_assign_type(field, entry);
-	it = &field->state_data;
-	stamp = ktime_to_timespec(it->stamp);
-	duration = ktime_to_timespec(ktime_sub(it->end, it->stamp));
-
-	if (entry->type == TRACE_POWER) {
-		if (it->type == POWER_CSTATE)
-			ret = trace_seq_printf(s, "[%5ld.%09ld] CSTATE: Going to C%i on cpu %i for %ld.%09ld\n",
-					  stamp.tv_sec,
-					  stamp.tv_nsec,
-					  it->state, iter->cpu,
-					  duration.tv_sec,
-					  duration.tv_nsec);
-		if (it->type == POWER_PSTATE)
-			ret = trace_seq_printf(s, "[%5ld.%09ld] PSTATE: Going to P%i on cpu %i\n",
-					  stamp.tv_sec,
-					  stamp.tv_nsec,
-					  it->state, iter->cpu);
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-		return TRACE_TYPE_HANDLED;
-	}
-	return TRACE_TYPE_UNHANDLED;
-}
-
-static void power_print_header(struct seq_file *s)
-{
-	seq_puts(s, "#   TIMESTAMP      STATE  EVENT\n");
-	seq_puts(s, "#       |            |      |\n");
-}
-
-static struct tracer power_tracer __read_mostly =
-{
-	.name		= "power",
-	.init		= power_trace_init,
-	.start		= start_power_trace,
-	.stop		= stop_power_trace,
-	.reset		= power_trace_reset,
-	.print_line	= power_print_line,
-	.print_header	= power_print_header,
-};
-
-static int init_power_trace(void)
-{
-	return register_tracer(&power_tracer);
-}
-device_initcall(init_power_trace);
diff --git a/kernel/trace/trace_printk.c b/kernel/trace/trace_printk.c
index 687699d365a..2547d8813cf 100644
--- a/kernel/trace/trace_printk.c
+++ b/kernel/trace/trace_printk.c
@@ -11,7 +11,6 @@
 #include <linux/ftrace.h>
 #include <linux/string.h>
 #include <linux/module.h>
-#include <linux/marker.h>
 #include <linux/mutex.h>
 #include <linux/ctype.h>
 #include <linux/list.h>
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index 0f6facb050a..8504ac71e4e 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -296,14 +296,14 @@ static const struct file_operations stack_trace_fops = {
 
 int
 stack_trace_sysctl(struct ctl_table *table, int write,
-		   struct file *file, void __user *buffer, size_t *lenp,
+		   void __user *buffer, size_t *lenp,
 		   loff_t *ppos)
 {
 	int ret;
 
 	mutex_lock(&stack_sysctl_mutex);
 
-	ret = proc_dointvec(table, write, file, buffer, lenp, ppos);
+	ret = proc_dointvec(table, write, buffer, lenp, ppos);
 
 	if (ret || !write ||
 	    (last_stack_tracer_enabled == !!stack_tracer_enabled))
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 8712ce3c6a0..527e17eae57 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -2,7 +2,7 @@
 #include <trace/events/syscalls.h>
 #include <linux/kernel.h>
 #include <linux/ftrace.h>
-#include <linux/perf_counter.h>
+#include <linux/perf_event.h>
 #include <asm/syscall.h>
 
 #include "trace_output.h"
@@ -166,7 +166,7 @@ int syscall_exit_format(struct ftrace_event_call *call, struct trace_seq *s)
 			       "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
 			       "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n",
 			       SYSCALL_FIELD(int, nr),
-			       SYSCALL_FIELD(unsigned long, ret));
+			       SYSCALL_FIELD(long, ret));
 	if (!ret)
 		return 0;
 
@@ -212,7 +212,7 @@ int syscall_exit_define_fields(struct ftrace_event_call *call)
 	if (ret)
 		return ret;
 
-	ret = trace_define_field(call, SYSCALL_FIELD(unsigned long, ret), 0,
+	ret = trace_define_field(call, SYSCALL_FIELD(long, ret), 0,
 				 FILTER_OTHER);
 
 	return ret;
@@ -384,10 +384,13 @@ static int sys_prof_refcount_exit;
 
 static void prof_syscall_enter(struct pt_regs *regs, long id)
 {
-	struct syscall_trace_enter *rec;
 	struct syscall_metadata *sys_data;
+	struct syscall_trace_enter *rec;
+	unsigned long flags;
+	char *raw_data;
 	int syscall_nr;
 	int size;
+	int cpu;
 
 	syscall_nr = syscall_get_nr(current, regs);
 	if (!test_bit(syscall_nr, enabled_prof_enter_syscalls))
@@ -402,20 +405,38 @@ static void prof_syscall_enter(struct pt_regs *regs, long id)
 	size = ALIGN(size + sizeof(u32), sizeof(u64));
 	size -= sizeof(u32);
 
-	do {
-		char raw_data[size];
+	if (WARN_ONCE(size > FTRACE_MAX_PROFILE_SIZE,
+		      "profile buffer not large enough"))
+		return;
+
+	/* Protect the per cpu buffer, begin the rcu read side */
+	local_irq_save(flags);
 
-		/* zero the dead bytes from align to not leak stack to user */
-		*(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
+	cpu = smp_processor_id();
+
+	if (in_nmi())
+		raw_data = rcu_dereference(trace_profile_buf_nmi);
+	else
+		raw_data = rcu_dereference(trace_profile_buf);
+
+	if (!raw_data)
+		goto end;
 
-		rec = (struct syscall_trace_enter *) raw_data;
-		tracing_generic_entry_update(&rec->ent, 0, 0);
-		rec->ent.type = sys_data->enter_id;
-		rec->nr = syscall_nr;
-		syscall_get_arguments(current, regs, 0, sys_data->nb_args,
-				       (unsigned long *)&rec->args);
-		perf_tpcounter_event(sys_data->enter_id, 0, 1, rec, size);
-	} while(0);
+	raw_data = per_cpu_ptr(raw_data, cpu);
+
+	/* zero the dead bytes from align to not leak stack to user */
+	*(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
+
+	rec = (struct syscall_trace_enter *) raw_data;
+	tracing_generic_entry_update(&rec->ent, 0, 0);
+	rec->ent.type = sys_data->enter_id;
+	rec->nr = syscall_nr;
+	syscall_get_arguments(current, regs, 0, sys_data->nb_args,
+			       (unsigned long *)&rec->args);
+	perf_tp_event(sys_data->enter_id, 0, 1, rec, size);
+
+end:
+	local_irq_restore(flags);
 }
 
 int reg_prof_syscall_enter(char *name)
@@ -460,8 +481,12 @@ void unreg_prof_syscall_enter(char *name)
 static void prof_syscall_exit(struct pt_regs *regs, long ret)
 {
 	struct syscall_metadata *sys_data;
-	struct syscall_trace_exit rec;
+	struct syscall_trace_exit *rec;
+	unsigned long flags;
 	int syscall_nr;
+	char *raw_data;
+	int size;
+	int cpu;
 
 	syscall_nr = syscall_get_nr(current, regs);
 	if (!test_bit(syscall_nr, enabled_prof_exit_syscalls))
@@ -471,12 +496,46 @@ static void prof_syscall_exit(struct pt_regs *regs, long ret)
 	if (!sys_data)
 		return;
 
-	tracing_generic_entry_update(&rec.ent, 0, 0);
-	rec.ent.type = sys_data->exit_id;
-	rec.nr = syscall_nr;
-	rec.ret = syscall_get_return_value(current, regs);
+	/* We can probably do that at build time */
+	size = ALIGN(sizeof(*rec) + sizeof(u32), sizeof(u64));
+	size -= sizeof(u32);
 
-	perf_tpcounter_event(sys_data->exit_id, 0, 1, &rec, sizeof(rec));
+	/*
+	 * Impossible, but be paranoid with the future
+	 * How to put this check outside runtime?
+	 */
+	if (WARN_ONCE(size > FTRACE_MAX_PROFILE_SIZE,
+		"exit event has grown above profile buffer size"))
+		return;
+
+	/* Protect the per cpu buffer, begin the rcu read side */
+	local_irq_save(flags);
+	cpu = smp_processor_id();
+
+	if (in_nmi())
+		raw_data = rcu_dereference(trace_profile_buf_nmi);
+	else
+		raw_data = rcu_dereference(trace_profile_buf);
+
+	if (!raw_data)
+		goto end;
+
+	raw_data = per_cpu_ptr(raw_data, cpu);
+
+	/* zero the dead bytes from align to not leak stack to user */
+	*(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
+
+	rec = (struct syscall_trace_exit *)raw_data;
+
+	tracing_generic_entry_update(&rec->ent, 0, 0);
+	rec->ent.type = sys_data->exit_id;
+	rec->nr = syscall_nr;
+	rec->ret = syscall_get_return_value(current, regs);
+
+	perf_tp_event(sys_data->exit_id, 0, 1, rec, size);
+
+end:
+	local_irq_restore(flags);
 }
 
 int reg_prof_syscall_exit(char *name)
diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
index 9489a0a9b1b..cc89be5bc0f 100644
--- a/kernel/tracepoint.c
+++ b/kernel/tracepoint.c
@@ -48,7 +48,7 @@ static struct hlist_head tracepoint_table[TRACEPOINT_TABLE_SIZE];
 
 /*
  * Note about RCU :
- * It is used to to delay the free of multiple probes array until a quiescent
+ * It is used to delay the free of multiple probes array until a quiescent
  * state is reached.
  * Tracepoint entries modifications are protected by the tracepoints_mutex.
  */
diff --git a/kernel/uid16.c b/kernel/uid16.c
index 0314501688b..419209893d8 100644
--- a/kernel/uid16.c
+++ b/kernel/uid16.c
@@ -4,7 +4,6 @@
  */
 
 #include <linux/mm.h>
-#include <linux/utsname.h>
 #include <linux/mman.h>
 #include <linux/notifier.h>
 #include <linux/reboot.h>
diff --git a/kernel/utsname_sysctl.c b/kernel/utsname_sysctl.c
index 92359cc747a..69eae358a72 100644
--- a/kernel/utsname_sysctl.c
+++ b/kernel/utsname_sysctl.c
@@ -42,14 +42,14 @@ static void put_uts(ctl_table *table, int write, void *which)
  *	Special case of dostring for the UTS structure. This has locks
  *	to observe. Should this be in kernel/sys.c ????
  */
-static int proc_do_uts_string(ctl_table *table, int write, struct file *filp,
+static int proc_do_uts_string(ctl_table *table, int write,
 		  void __user *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct ctl_table uts_table;
 	int r;
 	memcpy(&uts_table, table, sizeof(uts_table));
 	uts_table.data = get_uts(table, write);
-	r = proc_dostring(&uts_table,write,filp,buffer,lenp, ppos);
+	r = proc_dostring(&uts_table,write,buffer,lenp, ppos);
 	put_uts(table, write, uts_table.data);
 	return r;
 }
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index addfe2df93b..47cdd7e76f2 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -640,6 +640,24 @@ int schedule_delayed_work(struct delayed_work *dwork,
 EXPORT_SYMBOL(schedule_delayed_work);
 
 /**
+ * flush_delayed_work - block until a dwork_struct's callback has terminated
+ * @dwork: the delayed work which is to be flushed
+ *
+ * Any timeout is cancelled, and any pending work is run immediately.
+ */
+void flush_delayed_work(struct delayed_work *dwork)
+{
+	if (del_timer_sync(&dwork->timer)) {
+		struct cpu_workqueue_struct *cwq;
+		cwq = wq_per_cpu(keventd_wq, get_cpu());
+		__queue_work(cwq, &dwork->work);
+		put_cpu();
+	}
+	flush_work(&dwork->work);
+}
+EXPORT_SYMBOL(flush_delayed_work);
+
+/**
  * schedule_delayed_work_on - queue work in global workqueue on CPU after delay
  * @cpu: cpu to use
  * @dwork: job to be done