diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/Kconfig.freezer | 2 | ||||
| -rw-r--r-- | kernel/Makefile | 2 | ||||
| -rw-r--r-- | kernel/cgroup.c | 265 | ||||
| -rw-r--r-- | kernel/cgroup_debug.c | 4 | ||||
| -rw-r--r-- | kernel/cgroup_freezer.c | 379 | ||||
| -rw-r--r-- | kernel/configs.c | 9 | ||||
| -rw-r--r-- | kernel/cpuset.c | 17 | ||||
| -rw-r--r-- | kernel/freezer.c | 154 | ||||
| -rw-r--r-- | kernel/kexec.c | 2 | ||||
| -rw-r--r-- | kernel/kthread.c | 5 | ||||
| -rw-r--r-- | kernel/power/process.c | 119 | ||||
| -rw-r--r-- | kernel/ptrace.c | 2 | ||||
| -rw-r--r-- | kernel/rcupreempt.c | 2 | ||||
| -rw-r--r-- | kernel/rcutorture.c | 2 | ||||
| -rw-r--r-- | kernel/sysctl.c | 10 |
15 files changed, 724 insertions, 250 deletions
diff --git a/kernel/Kconfig.freezer b/kernel/Kconfig.freezer new file mode 100644 index 00000000000..a3bb4cb5253 --- /dev/null +++ b/kernel/Kconfig.freezer @@ -0,0 +1,2 @@ +config FREEZER + def_bool PM_SLEEP || CGROUP_FREEZER diff --git a/kernel/Makefile b/kernel/Makefile index 4e1d7df7c3e..066550aa61c 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -24,6 +24,7 @@ CFLAGS_REMOVE_sched_clock.o = -pg CFLAGS_REMOVE_sched.o = -mno-spe -pg endif +obj-$(CONFIG_FREEZER) += freezer.o obj-$(CONFIG_PROFILING) += profile.o obj-$(CONFIG_SYSCTL_SYSCALL_CHECK) += sysctl_check.o obj-$(CONFIG_STACKTRACE) += stacktrace.o @@ -55,6 +56,7 @@ 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-$(CONFIG_CGROUP_NS) += ns_cgroup.o obj-$(CONFIG_UTS_NS) += utsname.o diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 8c6e1c17e6d..046c1609606 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -241,7 +241,6 @@ static void unlink_css_set(struct css_set *cg) struct cg_cgroup_link *link; struct cg_cgroup_link *saved_link; - write_lock(&css_set_lock); hlist_del(&cg->hlist); css_set_count--; @@ -251,16 +250,25 @@ static void unlink_css_set(struct css_set *cg) list_del(&link->cgrp_link_list); kfree(link); } - - write_unlock(&css_set_lock); } -static void __release_css_set(struct kref *k, int taskexit) +static void __put_css_set(struct css_set *cg, int taskexit) { int i; - struct css_set *cg = container_of(k, struct css_set, ref); - + /* + * Ensure that the refcount doesn't hit zero while any readers + * can see it. Similar to atomic_dec_and_lock(), but for an + * rwlock + */ + if (atomic_add_unless(&cg->refcount, -1, 1)) + return; + write_lock(&css_set_lock); + if (!atomic_dec_and_test(&cg->refcount)) { + 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++) { @@ -276,32 +284,22 @@ static void __release_css_set(struct kref *k, int taskexit) kfree(cg); } -static void release_css_set(struct kref *k) -{ - __release_css_set(k, 0); -} - -static void release_css_set_taskexit(struct kref *k) -{ - __release_css_set(k, 1); -} - /* * refcounted get/put for css_set objects */ static inline void get_css_set(struct css_set *cg) { - kref_get(&cg->ref); + atomic_inc(&cg->refcount); } static inline void put_css_set(struct css_set *cg) { - kref_put(&cg->ref, release_css_set); + __put_css_set(cg, 0); } static inline void put_css_set_taskexit(struct css_set *cg) { - kref_put(&cg->ref, release_css_set_taskexit); + __put_css_set(cg, 1); } /* @@ -427,7 +425,7 @@ static struct css_set *find_css_set( return NULL; } - kref_init(&res->ref); + atomic_set(&res->refcount, 1); INIT_LIST_HEAD(&res->cg_links); INIT_LIST_HEAD(&res->tasks); INIT_HLIST_NODE(&res->hlist); @@ -870,6 +868,14 @@ static struct super_operations cgroup_ops = { .remount_fs = cgroup_remount, }; +static void init_cgroup_housekeeping(struct cgroup *cgrp) +{ + INIT_LIST_HEAD(&cgrp->sibling); + INIT_LIST_HEAD(&cgrp->children); + INIT_LIST_HEAD(&cgrp->css_sets); + INIT_LIST_HEAD(&cgrp->release_list); + init_rwsem(&cgrp->pids_mutex); +} static void init_cgroup_root(struct cgroupfs_root *root) { struct cgroup *cgrp = &root->top_cgroup; @@ -878,10 +884,7 @@ static void init_cgroup_root(struct cgroupfs_root *root) root->number_of_cgroups = 1; cgrp->root = root; cgrp->top_cgroup = cgrp; - INIT_LIST_HEAD(&cgrp->sibling); - INIT_LIST_HEAD(&cgrp->children); - INIT_LIST_HEAD(&cgrp->css_sets); - INIT_LIST_HEAD(&cgrp->release_list); + init_cgroup_housekeeping(cgrp); } static int cgroup_test_super(struct super_block *sb, void *data) @@ -1728,7 +1731,7 @@ int cgroup_task_count(const struct cgroup *cgrp) read_lock(&css_set_lock); list_for_each_entry(link, &cgrp->css_sets, cgrp_link_list) { - count += atomic_read(&link->cg->ref.refcount); + count += atomic_read(&link->cg->refcount); } read_unlock(&css_set_lock); return count; @@ -1997,16 +2000,7 @@ int cgroup_scan_tasks(struct cgroup_scanner *scan) * but we cannot guarantee that the information we produce is correct * unless we produce it entirely atomically. * - * Upon tasks file open(), a struct ctr_struct is allocated, that - * will have a pointer to an array (also allocated here). The struct - * ctr_struct * is stored in file->private_data. Its resources will - * be freed by release() when the file is closed. The array is used - * to sprintf the PIDs and then used by read(). */ -struct ctr_struct { - char *buf; - int bufsz; -}; /* * Load into 'pidarray' up to 'npids' of the tasks using cgroup @@ -2088,42 +2082,132 @@ static int cmppid(const void *a, const void *b) return *(pid_t *)a - *(pid_t *)b; } + /* - * Convert array 'a' of 'npids' pid_t's to a string of newline separated - * decimal pids in 'buf'. Don't write more than 'sz' chars, but return - * count 'cnt' of how many chars would be written if buf were large enough. + * seq_file methods for the "tasks" file. 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. */ -static int pid_array_to_buf(char *buf, int sz, pid_t *a, int npids) + +static void *cgroup_tasks_start(struct seq_file *s, loff_t *pos) { - int cnt = 0; - int i; + /* + * Initially we receive a position value that corresponds to + * one more than the last pid shown (or 0 on the first call or + * after a seek to the start). Use a binary-search to find the + * next pid to display, if any + */ + struct cgroup *cgrp = s->private; + int index = 0, pid = *pos; + int *iter; - for (i = 0; i < npids; i++) - cnt += snprintf(buf + cnt, max(sz - cnt, 0), "%d\n", a[i]); - return cnt; + down_read(&cgrp->pids_mutex); + if (pid) { + int end = cgrp->pids_length; + int i; + while (index < end) { + int mid = (index + end) / 2; + if (cgrp->tasks_pids[mid] == pid) { + index = mid; + break; + } else if (cgrp->tasks_pids[mid] <= pid) + index = mid + 1; + else + end = mid; + } + } + /* If we're off the end of the array, we're done */ + if (index >= cgrp->pids_length) + return NULL; + /* Update the abstract position to be the actual pid that we found */ + iter = cgrp->tasks_pids + index; + *pos = *iter; + return iter; +} + +static void cgroup_tasks_stop(struct seq_file *s, void *v) +{ + struct cgroup *cgrp = s->private; + up_read(&cgrp->pids_mutex); } +static void *cgroup_tasks_next(struct seq_file *s, void *v, loff_t *pos) +{ + struct cgroup *cgrp = s->private; + int *p = v; + int *end = cgrp->tasks_pids + cgrp->pids_length; + + /* + * Advance to the next pid in the array. If this goes off the + * end, we're done + */ + p++; + if (p >= end) { + return NULL; + } else { + *pos = *p; + return p; + } +} + +static int cgroup_tasks_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, +}; + +static void release_cgroup_pid_array(struct cgroup *cgrp) +{ + down_write(&cgrp->pids_mutex); + BUG_ON(!cgrp->pids_use_count); + if (!--cgrp->pids_use_count) { + kfree(cgrp->tasks_pids); + cgrp->tasks_pids = NULL; + cgrp->pids_length = 0; + } + up_write(&cgrp->pids_mutex); +} + +static int cgroup_tasks_release(struct inode *inode, struct file *file) +{ + struct cgroup *cgrp = __d_cgrp(file->f_dentry->d_parent); + + if (!(file->f_mode & FMODE_READ)) + return 0; + + release_cgroup_pid_array(cgrp); + return seq_release(inode, file); +} + +static struct file_operations cgroup_tasks_operations = { + .read = seq_read, + .llseek = seq_lseek, + .write = cgroup_file_write, + .release = cgroup_tasks_release, +}; + /* - * Handle an open on 'tasks' file. Prepare a buffer listing the + * Handle an open on 'tasks' file. Prepare an array containing the * process id's of tasks currently attached to the cgroup being opened. - * - * Does not require any specific cgroup mutexes, and does not take any. */ + static int cgroup_tasks_open(struct inode *unused, struct file *file) { struct cgroup *cgrp = __d_cgrp(file->f_dentry->d_parent); - struct ctr_struct *ctr; pid_t *pidarray; int npids; - char c; + int retval; + /* Nothing to do for write-only files */ if (!(file->f_mode & FMODE_READ)) return 0; - ctr = kmalloc(sizeof(*ctr), GFP_KERNEL); - if (!ctr) - goto err0; - /* * If cgroup gets more users after we read count, we won't have * enough space - tough. This race is indistinguishable to the @@ -2131,57 +2215,31 @@ static int cgroup_tasks_open(struct inode *unused, struct file *file) * show up until sometime later on. */ npids = cgroup_task_count(cgrp); - if (npids) { - pidarray = kmalloc(npids * sizeof(pid_t), GFP_KERNEL); - if (!pidarray) - goto err1; - - npids = pid_array_load(pidarray, npids, cgrp); - sort(pidarray, npids, sizeof(pid_t), cmppid, NULL); - - /* Call pid_array_to_buf() twice, first just to get bufsz */ - ctr->bufsz = pid_array_to_buf(&c, sizeof(c), pidarray, npids) + 1; - ctr->buf = kmalloc(ctr->bufsz, GFP_KERNEL); - if (!ctr->buf) - goto err2; - ctr->bufsz = pid_array_to_buf(ctr->buf, ctr->bufsz, pidarray, npids); - - kfree(pidarray); - } else { - ctr->buf = NULL; - ctr->bufsz = 0; - } - file->private_data = ctr; - return 0; - -err2: - kfree(pidarray); -err1: - kfree(ctr); -err0: - return -ENOMEM; -} + 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); -static ssize_t cgroup_tasks_read(struct cgroup *cgrp, - struct cftype *cft, - struct file *file, char __user *buf, - size_t nbytes, loff_t *ppos) -{ - struct ctr_struct *ctr = file->private_data; + /* + * Store the array in the cgroup, freeing the old + * array if necessary + */ + down_write(&cgrp->pids_mutex); + kfree(cgrp->tasks_pids); + cgrp->tasks_pids = pidarray; + cgrp->pids_length = npids; + cgrp->pids_use_count++; + up_write(&cgrp->pids_mutex); - return simple_read_from_buffer(buf, nbytes, ppos, ctr->buf, ctr->bufsz); -} + file->f_op = &cgroup_tasks_operations; -static int cgroup_tasks_release(struct inode *unused_inode, - struct file *file) -{ - struct ctr_struct *ctr; - - if (file->f_mode & FMODE_READ) { - ctr = file->private_data; - kfree(ctr->buf); - kfree(ctr); + retval = seq_open(file, &cgroup_tasks_seq_operations); + if (retval) { + release_cgroup_pid_array(cgrp); + return retval; } + ((struct seq_file *)file->private_data)->private = cgrp; return 0; } @@ -2210,7 +2268,6 @@ static struct cftype files[] = { { .name = "tasks", .open = cgroup_tasks_open, - .read = cgroup_tasks_read, .write_u64 = cgroup_tasks_write, .release = cgroup_tasks_release, .private = FILE_TASKLIST, @@ -2300,10 +2357,7 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry, mutex_lock(&cgroup_mutex); - INIT_LIST_HEAD(&cgrp->sibling); - INIT_LIST_HEAD(&cgrp->children); - INIT_LIST_HEAD(&cgrp->css_sets); - INIT_LIST_HEAD(&cgrp->release_list); + init_cgroup_housekeeping(cgrp); cgrp->parent = parent; cgrp->root = parent->root; @@ -2495,8 +2549,7 @@ static void __init cgroup_init_subsys(struct cgroup_subsys *ss) int __init cgroup_init_early(void) { int i; - kref_init(&init_css_set.ref); - kref_get(&init_css_set.ref); + atomic_set(&init_css_set.refcount, 1); INIT_LIST_HEAD(&init_css_set.cg_links); INIT_LIST_HEAD(&init_css_set.tasks); INIT_HLIST_NODE(&init_css_set.hlist); diff --git a/kernel/cgroup_debug.c b/kernel/cgroup_debug.c index c3dc3aba4c0..daca6209202 100644 --- a/kernel/cgroup_debug.c +++ b/kernel/cgroup_debug.c @@ -57,7 +57,7 @@ static u64 current_css_set_refcount_read(struct cgroup *cont, u64 count; rcu_read_lock(); - count = atomic_read(¤t->cgroups->ref.refcount); + count = atomic_read(¤t->cgroups->refcount); rcu_read_unlock(); return count; } @@ -90,7 +90,7 @@ static struct cftype files[] = { { .name = "releasable", .read_u64 = releasable_read, - } + }, }; static int debug_populate(struct cgroup_subsys *ss, struct cgroup *cont) diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c new file mode 100644 index 00000000000..e9505695449 --- /dev/null +++ b/kernel/cgroup_freezer.c @@ -0,0 +1,379 @@ +/* + * cgroup_freezer.c - control group freezer subsystem + * + * Copyright IBM Corporation, 2007 + * + * Author : Cedric Le Goater <clg@fr.ibm.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of version 2.1 of the GNU Lesser General Public License + * as published by the Free Software Foundation. + * + * This program is distributed in the hope that it would be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. + */ + +#include <linux/module.h> +#include <linux/cgroup.h> +#include <linux/fs.h> +#include <linux/uaccess.h> +#include <linux/freezer.h> +#include <linux/seq_file.h> + +enum freezer_state { + CGROUP_THAWED = 0, + CGROUP_FREEZING, + CGROUP_FROZEN, +}; + +struct freezer { + struct cgroup_subsys_state css; + enum freezer_state state; + spinlock_t lock; /* protects _writes_ to state */ +}; + +static inline struct freezer *cgroup_freezer( + struct cgroup *cgroup) +{ + return container_of( + cgroup_subsys_state(cgroup, freezer_subsys_id), + struct freezer, css); +} + +static inline struct freezer *task_freezer(struct task_struct *task) +{ + return container_of(task_subsys_state(task, freezer_subsys_id), + struct freezer, css); +} + +int cgroup_frozen(struct task_struct *task) +{ + struct freezer *freezer; + enum freezer_state state; + + task_lock(task); + freezer = task_freezer(task); + state = freezer->state; + task_unlock(task); + + return state == CGROUP_FROZEN; +} + +/* + * cgroups_write_string() limits the size of freezer state strings to + * CGROUP_LOCAL_BUFFER_SIZE + */ +static const char *freezer_state_strs[] = { + "THAWED", + "FREEZING", + "FROZEN", +}; + +/* + * State diagram + * Transitions are caused by userspace writes to the freezer.state file. + * The values in parenthesis are state labels. The rest are edge labels. + * + * (THAWED) --FROZEN--> (FREEZING) --FROZEN--> (FROZEN) + * ^ ^ | | + * | \_______THAWED_______/ | + * \__________________________THAWED____________/ + */ + +struct cgroup_subsys freezer_subsys; + +/* Locks taken and their ordering + * ------------------------------ + * css_set_lock + * cgroup_mutex (AKA cgroup_lock) + * task->alloc_lock (AKA task_lock) + * freezer->lock + * task->sighand->siglock + * + * cgroup code forces css_set_lock to be taken before task->alloc_lock + * + * freezer_create(), freezer_destroy(): + * cgroup_mutex [ by cgroup core ] + * + * can_attach(): + * cgroup_mutex + * + * cgroup_frozen(): + * task->alloc_lock (to get task's cgroup) + * + * freezer_fork() (preserving fork() performance means can't take cgroup_mutex): + * task->alloc_lock (to get task's cgroup) + * freezer->lock + * sighand->siglock (if the cgroup is freezing) + * + * freezer_read(): + * cgroup_mutex + * freezer->lock + * read_lock css_set_lock (cgroup iterator start) + * + * freezer_write() (freeze): + * cgroup_mutex + * freezer->lock + * read_lock css_set_lock (cgroup iterator start) + * sighand->siglock + * + * freezer_write() (unfreeze): + * cgroup_mutex + * freezer->lock + * read_lock css_set_lock (cgroup iterator start) + * task->alloc_lock (to prevent races with freeze_task()) + * sighand->siglock + */ +static struct cgroup_subsys_state *freezer_create(struct cgroup_subsys *ss, + struct cgroup *cgroup) +{ + struct freezer *freezer; + + freezer = kzalloc(sizeof(struct freezer), GFP_KERNEL); + if (!freezer) + return ERR_PTR(-ENOMEM); + + spin_lock_init(&freezer->lock); + freezer->state = CGROUP_THAWED; + return &freezer->css; +} + +static void freezer_destroy(struct cgroup_subsys *ss, + struct cgroup *cgroup) +{ + kfree(cgroup_freezer(cgroup)); +} + +/* Task is frozen or will freeze immediately when next it gets woken */ +static bool is_task_frozen_enough(struct task_struct *task) +{ + return frozen(task) || + (task_is_stopped_or_traced(task) && freezing(task)); +} + +/* + * The call to cgroup_lock() in the freezer.state write method prevents + * a write to that file racing against an attach, and hence the + * can_attach() result will remain valid until the attach completes. + */ +static int freezer_can_attach(struct cgroup_subsys *ss, + struct cgroup *new_cgroup, + struct task_struct *task) +{ + struct freezer *freezer; + int retval; + + /* Anything frozen can't move or be moved to/from */ + + if (is_task_frozen_enough(task)) + return -EBUSY; + + freezer = cgroup_freezer(new_cgroup); + if (freezer->state == CGROUP_FROZEN) + return -EBUSY; + + retval = 0; + task_lock(task); + freezer = task_freezer(task); + if (freezer->state == CGROUP_FROZEN) + retval = -EBUSY; + task_unlock(task); + return retval; +} + +static void freezer_fork(struct cgroup_subsys *ss, struct task_struct *task) +{ + struct freezer *freezer; + + task_lock(task); + freezer = task_freezer(task); + task_unlock(task); + + BUG_ON(freezer->state == CGROUP_FROZEN); + spin_lock_irq(&freezer->lock); + /* Locking avoids race with FREEZING -> THAWED transitions. */ + if (freezer->state == CGROUP_FREEZING) + freeze_task(task, true); + spin_unlock_irq(&freezer->lock); +} + +/* + * caller must hold freezer->lock + */ +static void update_freezer_state(struct cgroup *cgroup, + struct freezer *freezer) +{ + struct cgroup_iter it; + struct task_struct *task; + unsigned int nfrozen = 0, ntotal = 0; + + cgroup_iter_start(cgroup, &it); + while ((task = cgroup_iter_next(cgroup, &it))) { + ntotal++; + if (is_task_frozen_enough(task)) + nfrozen++; + } + + /* + * Transition to FROZEN when no new tasks can be added ensures + * that we never exist in the FROZEN state while there are unfrozen + * tasks. + */ + if (nfrozen == ntotal) + freezer->state = CGROUP_FROZEN; + else if (nfrozen > 0) + freezer->state = CGROUP_FREEZING; + else + freezer->state = CGROUP_THAWED; + cgroup_iter_end(cgroup, &it); +} + +static int freezer_read(struct cgroup *cgroup, struct cftype *cft, + struct seq_file *m) +{ + struct freezer *freezer; + enum freezer_state state; + + if (!cgroup_lock_live_group(cgroup)) + return -ENODEV; + + freezer = cgroup_freezer(cgroup); + spin_lock_irq(&freezer->lock); + state = freezer->state; + if (state == CGROUP_FREEZING) { + /* We change from FREEZING to FROZEN lazily if the cgroup was + * only partially frozen when we exitted write. */ + update_freezer_state(cgroup, freezer); + state = freezer->state; + } + spin_unlock_irq(&freezer->lock); + cgroup_unlock(); + + seq_puts(m, freezer_state_strs[state]); + seq_putc(m, '\n'); + return 0; +} + +static int try_to_freeze_cgroup(struct cgroup *cgroup, struct freezer *freezer) +{ + struct cgroup_iter it; + struct task_struct *task; + unsigned int num_cant_freeze_now = 0; + + freezer->state = CGROUP_FREEZING; + cgroup_iter_start(cgroup, &it); + while ((task = cgroup_iter_next(cgroup, &it))) { + if (!freeze_task(task, true)) + continue; + if (is_task_frozen_enough(task)) + continue; + if (!freezing(task) && !freezer_should_skip(task)) + num_cant_freeze_now++; + } + cgroup_iter_end(cgroup, &it); + + return num_cant_freeze_now ? -EBUSY : 0; +} + +static int unfreeze_cgroup(struct cgroup *cgroup, struct freezer *freezer) +{ + struct cgroup_iter it; + struct task_struct *task; + + cgroup_iter_start(cgroup, &it); + while ((task = cgroup_iter_next(cgroup, &it))) { + int do_wake; + + task_lock(task); + do_wake = __thaw_process(task); + task_unlock(task); + if (do_wake) + wake_up_process(task); + } + cgroup_iter_end(cgroup, &it); + freezer->state = CGROUP_THAWED; + + return 0; +} + +static int freezer_change_state(struct cgroup *cgroup, + enum freezer_state goal_state) +{ + struct freezer *freezer; + int retval = 0; + + freezer = cgroup_freezer(cgroup); + spin_lock_irq(&freezer->lock); + update_freezer_state(cgroup, freezer); + if (goal_state == freezer->state) + goto out; + switch (freezer->state) { + case CGROUP_THAWED: + retval = try_to_freeze_cgroup(cgroup, freezer); + break; + case CGROUP_FREEZING: + if (goal_state == CGROUP_FROZEN) { + /* Userspace is retrying after + * "/bin/echo FROZEN > freezer.state" returned -EBUSY */ + retval = try_to_freeze_cgroup(cgroup, freezer); + break; + } + /* state == FREEZING and goal_state == THAWED, so unfreeze */ + case CGROUP_FROZEN: + retval = unfreeze_cgroup(cgroup, freezer); + break; + default: + break; + } +out: + spin_unlock_irq(&freezer->lock); + + return retval; +} + +static int freezer_write(struct cgroup *cgroup, + struct cftype *cft, + const char *buffer) +{ + int retval; + enum freezer_state goal_state; + + if (strcmp(buffer, freezer_state_strs[CGROUP_THAWED]) == 0) + goal_state = CGROUP_THAWED; + else if (strcmp(buffer, freezer_state_strs[CGROUP_FROZEN]) == 0) + goal_state = CGROUP_FROZEN; + else + return -EIO; + + if (!cgroup_lock_live_group(cgroup)) + return -ENODEV; + retval = freezer_change_state(cgroup, goal_state); + cgroup_unlock(); + return retval; +} + +static struct cftype files[] = { + { + .name = "state", + .read_seq_string = freezer_read, + .write_string = freezer_write, + }, +}; + +static int freezer_populate(struct cgroup_subsys *ss, struct cgroup *cgroup) +{ + return cgroup_add_files(cgroup, ss, files, ARRAY_SIZE(files)); +} + +struct cgroup_subsys freezer_subsys = { + .name = "freezer", + .create = freezer_create, + .destroy = freezer_destroy, + .populate = freezer_populate, + .subsys_id = freezer_subsys_id, + .can_attach = freezer_can_attach, + .attach = NULL, + .fork = freezer_fork, + .exit = NULL, +}; diff --git a/kernel/configs.c b/kernel/configs.c index 4c345210ed8..abaee684ecb 100644 --- a/kernel/configs.c +++ b/kernel/configs.c @@ -54,9 +54,6 @@ #ifdef CONFIG_IKCONFIG_PROC -/**************************************************/ -/* globals and useful constants */ - static ssize_t ikconfig_read_current(struct file *file, char __user *buf, size_t len, loff_t * offset) @@ -71,9 +68,6 @@ static const struct file_operations ikconfig_file_ops = { .read = ikconfig_read_current, }; -/***************************************************/ -/* ikconfig_init: start up everything we need to */ - static int __init ikconfig_init(void) { struct proc_dir_entry *entry; @@ -89,9 +83,6 @@ static int __init ikconfig_init(void) return 0; } -/***************************************************/ -/* ikconfig_cleanup: clean up our mess */ - static void __exit ikconfig_cleanup(void) { remove_proc_entry("config.gz", NULL); diff --git a/kernel/cpuset.c b/kernel/cpuset.c index eab7bd6628e..3e00526f52e 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -1172,7 +1172,7 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs, { struct cpuset trialcs; int err; - int cpus_nonempty, balance_flag_changed; + int balance_flag_changed; trialcs = *cs; if (turning_on) @@ -1184,7 +1184,6 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs, if (err < 0) return err; - cpus_nonempty = !cpus_empty(trialcs.cpus_allowed); balance_flag_changed = (is_sched_load_balance(cs) != is_sched_load_balance(&trialcs)); @@ -1192,7 +1191,7 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs, cs->flags = trialcs.flags; mutex_unlock(&callback_mutex); - if (cpus_nonempty && balance_flag_changed) + if (!cpus_empty(trialcs.cpus_allowed) && balance_flag_changed) async_rebuild_sched_domains(); return 0; @@ -2437,19 +2436,15 @@ const struct file_operations proc_cpuset_operations = { void cpuset_task_status_allowed(struct seq_file *m, struct task_struct *task) { seq_printf(m, "Cpus_allowed:\t"); - m->count += cpumask_scnprintf(m->buf + m->count, m->size - m->count, - task->cpus_allowed); + seq_cpumask(m, &task->cpus_allowed); seq_printf(m, "\n"); seq_printf(m, "Cpus_allowed_list:\t"); - m->count += cpulist_scnprintf(m->buf + m->count, m->size - m->count, - task->cpus_allowed); + seq_cpumask_list(m, &task->cpus_allowed); seq_printf(m, "\n"); seq_printf(m, "Mems_allowed:\t"); - m->count += nodemask_scnprintf(m->buf + m->count, m->size - m->count, - task->mems_allowed); + seq_nodemask(m, &task->mems_allowed); seq_printf(m, "\n"); seq_printf(m, "Mems_allowed_list:\t"); - m->count += nodelist_scnprintf(m->buf + m->count, m->size - m->count, - task->mems_allowed); + seq_nodemask_list(m, &task->mems_allowed); seq_printf(m, "\n"); } diff --git a/kernel/freezer.c b/kernel/freezer.c new file mode 100644 index 00000000000..ba6248b323e --- /dev/null +++ b/kernel/freezer.c @@ -0,0 +1,154 @@ +/* + * kernel/freezer.c - Function to freeze a process + * + * Originally from kernel/power/process.c + */ + +#include <linux/interrupt.h> +#include <linux/suspend.h> +#include <linux/module.h> +#include <linux/syscalls.h> +#include <linux/freezer.h> + +/* + * freezing is complete, mark current process as frozen + */ +static inline void frozen_process(void) +{ + if (!unlikely(current->flags & PF_NOFREEZE)) { + current->flags |= PF_FROZEN; + wmb(); + } + clear_freeze_flag(current); +} + +/* Refrigerator is place where frozen processes are stored :-). */ +void refrigerator(void) +{ + /* Hmm, should we be allowed to suspend when there are realtime + processes around? */ + long save; + + task_lock(current); + if (freezing(current)) { + frozen_process(); + task_unlock(current); + } else { + task_unlock(current); + return; + } + save = current->state; + pr_debug("%s entered refrigerator\n", current->comm); + + spin_lock_irq(¤t->sighand->siglock); + recalc_sigpending(); /* We sent fake signal, clean it up */ + spin_unlock_irq(¤t->sighand->siglock); + + for (;;) { + set_current_state(TASK_UNINTERRUPTIBLE); + if (!frozen(current)) + break; + schedule(); + } + pr_debug("%s left refrigerator\n", current->comm); + __set_current_state(save); +} +EXPORT_SYMBOL(refrigerator); + +static void fake_signal_wake_up(struct task_struct *p) +{ + unsigned long flags; + + spin_lock_irqsave(&p->sighand->siglock, flags); + signal_wake_up(p, 0); + spin_unlock_irqrestore(&p->sighand->siglock, flags); +} + +/** + * freeze_task - send a freeze request to given task + * @p: task to send the request to + * @sig_only: if set, the request will only be sent if the task has the + * PF_FREEZER_NOSIG flag unset + * Return value: 'false', if @sig_only is set and the task has + * PF_FREEZER_NOSIG set or the task is frozen, 'true', otherwise + * + * The freeze request is sent by setting the tasks's TIF_FREEZE flag and + * either sending a fake signal to it or waking it up, depending on whether + * or not it has PF_FREEZER_NOSIG set. If @sig_only is set and the task + * has PF_FREEZER_NOSIG set (ie. it is a typical kernel thread), its + * TIF_FREEZE flag will not be set. + */ +bool freeze_task(struct task_struct *p, bool sig_only) +{ + /* + * We first check if the task is freezing and next if it has already + * been frozen to avoid the race with frozen_process() which first marks + * the task as frozen and next clears its TIF_FREEZE. + */ + if (!freezing(p)) { + rmb(); + if (frozen(p)) + return false; + + if (!sig_only || should_send_signal(p)) + set_freeze_flag(p); + else + return false; + } + + if (should_send_signal(p)) { + if (!signal_pending(p)) + fake_signal_wake_up(p); + } else if (sig_only) { + return false; + } else { + wake_up_state(p, TASK_INTERRUPTIBLE); + } + + return true; +} + +void cancel_freezing(struct task_struct *p) +{ + unsigned long flags; + + if (freezing(p)) { + pr_debug(" clean up: %s\n", p->comm); + clear_freeze_flag(p); + spin_lock_irqsave(&p->sighand->siglock, flags); + recalc_sigpending_and_wake(p); + spin_unlock_irqrestore(&p->sighand->siglock, flags); + } +} + +/* + * Wake up a frozen process + * + * task_lock() is needed to prevent the race with refrigerator() which may + * occur if the freezing of tasks fails. Namely, without the lock, if the + * freezing of tasks failed, thaw_tasks() might have run before a task in + * refrigerator() could call frozen_process(), in which case the task would be + * frozen and no one would thaw it. + */ +int __thaw_process(struct task_struct *p) +{ + if (frozen(p)) { + p->flags &= ~PF_FROZEN; + return 1; + } + clear_freeze_flag(p); + return 0; +} + +int thaw_process(struct task_struct *p) +{ + task_lock(p); + if (__thaw_process(p) == 1) { + task_unlock(p); + wake_up_process(p); + return 1; + } + task_unlock(p); + return 0; +} +EXPORT_SYMBOL(thaw_process); diff --git a/kernel/kexec.c b/kernel/kexec.c index aef265325cd..777ac458ac9 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -1371,6 +1371,7 @@ static int __init crash_save_vmcoreinfo_init(void) VMCOREINFO_SYMBOL(node_online_map); VMCOREINFO_SYMBOL(swapper_pg_dir); VMCOREINFO_SYMBOL(_stext); + VMCOREINFO_SYMBOL(vmlist); #ifndef CONFIG_NEED_MULTIPLE_NODES VMCOREINFO_SYMBOL(mem_map); @@ -1406,6 +1407,7 @@ static int __init crash_save_vmcoreinfo_init(void) VMCOREINFO_OFFSET(free_area, free_list); VMCOREINFO_OFFSET(list_head, next); VMCOREINFO_OFFSET(list_head, prev); + VMCOREINFO_OFFSET(vm_struct, addr); VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER); VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES); VMCOREINFO_NUMBER(NR_FREE_PAGES); diff --git a/kernel/kthread.c b/kernel/kthread.c index 96cff2f8710..14ec64fe175 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -171,12 +171,11 @@ EXPORT_SYMBOL(kthread_create); */ void kthread_bind(struct task_struct *k, unsigned int cpu) { - if (k->state != TASK_UNINTERRUPTIBLE) { + /* Must have done schedule() in kthread() before we set_task_cpu */ + if (!wait_task_inactive(k, TASK_UNINTERRUPTIBLE)) { WARN_ON(1); return; } - /* Must have done schedule() in kthread() before we set_task_cpu */ - wait_task_inactive(k, 0); set_task_cpu(k, cpu); k->cpus_allowed = cpumask_of_cpu(cpu); k->rt.nr_cpus_allowed = 1; diff --git a/kernel/power/process.c b/kernel/power/process.c index 278946aecaf..ca634019497 100644 --- a/kernel/power/process.c +++ b/kernel/power/process.c @@ -28,121 +28,6 @@ static inline int freezeable(struct task_struct * p) return 1; } -/* - * freezing is complete, mark current process as frozen - */ -static inline void frozen_process(void) -{ - if (!unlikely(current->flags & PF_NOFREEZE)) { - current->flags |= PF_FROZEN; - wmb(); - } - clear_freeze_flag(current); -} - -/* Refrigerator is place where frozen processes are stored :-). */ -void refrigerator(void) -{ - /* Hmm, should we be allowed to suspend when there are realtime - processes around? */ - long save; - - task_lock(current); - if (freezing(current)) { - frozen_process(); - task_unlock(current); - } else { - task_unlock(current); - return; - } - save = current->state; - pr_debug("%s entered refrigerator\n", current->comm); - - spin_lock_irq(¤t->sighand->siglock); - recalc_sigpending(); /* We sent fake signal, clean it up */ - spin_unlock_irq(¤t->sighand->siglock); - - for (;;) { - set_current_state(TASK_UNINTERRUPTIBLE); - if (!frozen(current)) - break; - schedule(); - } - pr_debug("%s left refrigerator\n", current->comm); - __set_current_state(save); -} - -static void fake_signal_wake_up(struct task_struct *p) -{ - unsigned long flags; - - spin_lock_irqsave(&p->sighand->siglock, flags); - signal_wake_up(p, 0); - spin_unlock_irqrestore(&p->sighand->siglock, flags); -} - -static inline bool should_send_signal(struct task_struct *p) -{ - return !(p->flags & PF_FREEZER_NOSIG); -} - -/** - * freeze_task - send a freeze request to given task - * @p: task to send the request to - * @sig_only: if set, the request will only be sent if the task has the - * PF_FREEZER_NOSIG flag unset - * Return value: 'false', if @sig_only is set and the task has - * PF_FREEZER_NOSIG set or the task is frozen, 'true', otherwise - * - * The freeze request is sent by setting the tasks's TIF_FREEZE flag and - * either sending a fake signal to it or waking it up, depending on whether - * or not it has PF_FREEZER_NOSIG set. If @sig_only is set and the task - * has PF_FREEZER_NOSIG set (ie. it is a typical kernel thread), its - * TIF_FREEZE flag will not be set. - */ -static bool freeze_task(struct task_struct *p, bool sig_only) -{ - /* - * We first check if the task is freezing and next if it has already - * been frozen to avoid the race with frozen_process() which first marks - * the task as frozen and next clears its TIF_FREEZE. - */ - if (!freezing(p)) { - rmb(); - if (frozen(p)) - return false; - - if (!sig_only || should_send_signal(p)) - set_freeze_flag(p); - else - return false; - } - - if (should_send_signal(p)) { - if (!signal_pending(p)) - fake_signal_wake_up(p); - } else if (sig_only) { - return false; - } else { - wake_up_state(p, TASK_INTERRUPTIBLE); - } - - return true; -} - -static void cancel_freezing(struct task_struct *p) -{ - unsigned long flags; - - if (freezing(p)) { - pr_debug(" clean up: %s\n", p->comm); - clear_freeze_flag(p); - spin_lock_irqsave(&p->sighand->siglock, flags); - recalc_sigpending_and_wake(p); - spin_unlock_irqrestore(&p->sighand->siglock, flags); - } -} - static int try_to_freeze_tasks(bool sig_only) { struct task_struct *g, *p; @@ -250,6 +135,9 @@ static void thaw_tasks(bool nosig_only) if (nosig_only && should_send_signal(p)) continue; + if (cgroup_frozen(p)) + continue; + thaw_process(p); } while_each_thread(g, p); read_unlock(&tasklist_lock); @@ -264,4 +152,3 @@ void thaw_processes(void) printk("done.\n"); } -EXPORT_SYMBOL(refrigerator); diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 356699a96d5..1e68e4c39e2 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -45,7 +45,7 @@ void __ptrace_link(struct task_struct *child, struct task_struct *new_parent) * TASK_TRACED, resume it now. * Requires that irqs be disabled. */ -void ptrace_untrace(struct task_struct *child) +static void ptrace_untrace(struct task_struct *child) { spin_lock(&child->sighand->siglock); if (task_is_traced(child)) { diff --git a/kernel/rcupreempt.c b/kernel/rcupreempt.c index ca4bbbe04aa..59236e8b9da 100644 --- a/kernel/rcupreempt.c +++ b/kernel/rcupreempt.c @@ -54,9 +54,9 @@ #include <linux/cpu.h> #include <linux/random.h> #include <linux/delay.h> -#include <linux/byteorder/swabb.h> #include <linux/cpumask.h> #include <linux/rcupreempt_trace.h> +#include <asm/byteorder.h> /* * PREEMPT_RCU data structures. diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c index 90b5b123f7a..85cb90588a5 100644 --- a/kernel/rcutorture.c +++ b/kernel/rcutorture.c @@ -42,10 +42,10 @@ #include <linux/freezer.h> #include <linux/cpu.h> #include <linux/delay.h> -#include <linux/byteorder/swabb.h> #include <linux/stat.h> #include <linux/srcu.h> #include <linux/slab.h> +#include <asm/byteorder.h> MODULE_LICENSE("GPL"); MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com> and " diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 617d41e4d6a..b3cc73931d1 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -833,6 +833,16 @@ static struct ctl_table kern_table[] = { .proc_handler = &proc_dointvec, }, #endif +#ifdef CONFIG_UNEVICTABLE_LRU + { + .ctl_name = CTL_UNNUMBERED, + .procname = "scan_unevictable_pages", + .data = &scan_unevictable_pages, + .maxlen = sizeof(scan_unevictable_pages), + .mode = 0644, + .proc_handler = &scan_unevictable_handler, + }, +#endif /* * NOTE: do not add new entries to this table unless you have read * Documentation/sysctl/ctl_unnumbered.txt |