Merge branch 'master' into upstream

37 files changed, 4401 insertions, 931 deletions

diff --git a/kernel/Makefile b/kernel/Makefile
index 14f4d45e0ae..ac6b27abb1a 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -47,6 +47,7 @@ obj-$(CONFIG_GENERIC_HARDIRQS) += irq/
 obj-$(CONFIG_SECCOMP) += seccomp.o
 obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o
 obj-$(CONFIG_RELAY) += relay.o
+obj-$(CONFIG_SYSCTL) += utsname_sysctl.o
 obj-$(CONFIG_UTS_NS) += utsname.o
 obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o
 obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o
diff --git a/kernel/fork.c b/kernel/fork.c
index 0b6293d94d9..d154cc78648 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -858,7 +858,7 @@ static inline int copy_signal(unsigned long clone_flags, struct task_struct * ts
 	init_sigpending(&sig->shared_pending);
 	INIT_LIST_HEAD(&sig->posix_timers);
 
-	hrtimer_init(&sig->real_timer, CLOCK_MONOTONIC, HRTIMER_REL);
+	hrtimer_init(&sig->real_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 	sig->it_real_incr.tv64 = 0;
 	sig->real_timer.function = it_real_fn;
 	sig->tsk = tsk;
diff --git a/kernel/futex.c b/kernel/futex.c
index 5a737de857d..e749e7df14b 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -1134,7 +1134,7 @@ static int futex_lock_pi(u32 __user *uaddr, int detect, unsigned long sec,
 
 	if (sec != MAX_SCHEDULE_TIMEOUT) {
 		to = &timeout;
-		hrtimer_init(&to->timer, CLOCK_REALTIME, HRTIMER_ABS);
+		hrtimer_init(&to->timer, CLOCK_REALTIME, HRTIMER_MODE_ABS);
 		hrtimer_init_sleeper(to, current);
 		to->timer.expires = ktime_set(sec, nsec);
 	}
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index f44e499e8fc..476cb0c0b4a 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -1,8 +1,9 @@
 /*
  *  linux/kernel/hrtimer.c
  *
- *  Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de>
- *  Copyright(C) 2005, Red Hat, Inc., Ingo Molnar
+ *  Copyright(C) 2005-2006, Thomas Gleixner <tglx@linutronix.de>
+ *  Copyright(C) 2005-2007, Red Hat, Inc., Ingo Molnar
+ *  Copyright(C) 2006-2007  Timesys Corp., Thomas Gleixner
  *
  *  High-resolution kernel timers
  *
@@ -31,12 +32,17 @@
  */
 
 #include <linux/cpu.h>
+#include <linux/irq.h>
 #include <linux/module.h>
 #include <linux/percpu.h>
 #include <linux/hrtimer.h>
 #include <linux/notifier.h>
 #include <linux/syscalls.h>
+#include <linux/kallsyms.h>
 #include <linux/interrupt.h>
+#include <linux/tick.h>
+#include <linux/seq_file.h>
+#include <linux/err.h>
 
 #include <asm/uaccess.h>
 
@@ -45,7 +51,7 @@
  *
  * returns the time in ktime_t format
  */
-static ktime_t ktime_get(void)
+ktime_t ktime_get(void)
 {
 	struct timespec now;
 
@@ -59,7 +65,7 @@ static ktime_t ktime_get(void)
  *
  * returns the time in ktime_t format
  */
-static ktime_t ktime_get_real(void)
+ktime_t ktime_get_real(void)
 {
 	struct timespec now;
 
@@ -79,21 +85,22 @@ EXPORT_SYMBOL_GPL(ktime_get_real);
  * This ensures that we capture erroneous accesses to these clock ids
  * rather than moving them into the range of valid clock id's.
  */
-
-#define MAX_HRTIMER_BASES 2
-
-static DEFINE_PER_CPU(struct hrtimer_base, hrtimer_bases[MAX_HRTIMER_BASES]) =
+DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) =
 {
+
+	.clock_base =
 	{
-		.index = CLOCK_REALTIME,
-		.get_time = &ktime_get_real,
-		.resolution = KTIME_REALTIME_RES,
-	},
-	{
-		.index = CLOCK_MONOTONIC,
-		.get_time = &ktime_get,
-		.resolution = KTIME_MONOTONIC_RES,
-	},
+		{
+			.index = CLOCK_REALTIME,
+			.get_time = &ktime_get_real,
+			.resolution = KTIME_LOW_RES,
+		},
+		{
+			.index = CLOCK_MONOTONIC,
+			.get_time = &ktime_get,
+			.resolution = KTIME_LOW_RES,
+		},
+	}
 };
 
 /**
@@ -125,20 +132,35 @@ EXPORT_SYMBOL_GPL(ktime_get_ts);
  * Get the coarse grained time at the softirq based on xtime and
  * wall_to_monotonic.
  */
-static void hrtimer_get_softirq_time(struct hrtimer_base *base)
+static void hrtimer_get_softirq_time(struct hrtimer_cpu_base *base)
 {
 	ktime_t xtim, tomono;
+	struct timespec xts;
 	unsigned long seq;
 
 	do {
 		seq = read_seqbegin(&xtime_lock);
-		xtim = timespec_to_ktime(xtime);
-		tomono = timespec_to_ktime(wall_to_monotonic);
-
+#ifdef CONFIG_NO_HZ
+		getnstimeofday(&xts);
+#else
+		xts = xtime;
+#endif
 	} while (read_seqretry(&xtime_lock, seq));
 
-	base[CLOCK_REALTIME].softirq_time = xtim;
-	base[CLOCK_MONOTONIC].softirq_time = ktime_add(xtim, tomono);
+	xtim = timespec_to_ktime(xts);
+	tomono = timespec_to_ktime(wall_to_monotonic);
+	base->clock_base[CLOCK_REALTIME].softirq_time = xtim;
+	base->clock_base[CLOCK_MONOTONIC].softirq_time =
+		ktime_add(xtim, tomono);
+}
+
+/*
+ * Helper function to check, whether the timer is running the callback
+ * function
+ */
+static inline int hrtimer_callback_running(struct hrtimer *timer)
+{
+	return timer->state & HRTIMER_STATE_CALLBACK;
 }
 
 /*
@@ -147,8 +169,6 @@ static void hrtimer_get_softirq_time(struct hrtimer_base *base)
  */
 #ifdef CONFIG_SMP
 
-#define set_curr_timer(b, t)		do { (b)->curr_timer = (t); } while (0)
-
 /*
  * We are using hashed locking: holding per_cpu(hrtimer_bases)[n].lock
  * means that all timers which are tied to this base via timer->base are
@@ -161,19 +181,20 @@ static void hrtimer_get_softirq_time(struct hrtimer_base *base)
  * possible to set timer->base = NULL and drop the lock: the timer remains
  * locked.
  */
-static struct hrtimer_base *lock_hrtimer_base(const struct hrtimer *timer,
-					      unsigned long *flags)
+static
+struct hrtimer_clock_base *lock_hrtimer_base(const struct hrtimer *timer,
+					     unsigned long *flags)
 {
-	struct hrtimer_base *base;
+	struct hrtimer_clock_base *base;
 
 	for (;;) {
 		base = timer->base;
 		if (likely(base != NULL)) {
-			spin_lock_irqsave(&base->lock, *flags);
+			spin_lock_irqsave(&base->cpu_base->lock, *flags);
 			if (likely(base == timer->base))
 				return base;
 			/* The timer has migrated to another CPU: */
-			spin_unlock_irqrestore(&base->lock, *flags);
+			spin_unlock_irqrestore(&base->cpu_base->lock, *flags);
 		}
 		cpu_relax();
 	}
@@ -182,12 +203,14 @@ static struct hrtimer_base *lock_hrtimer_base(const struct hrtimer *timer,
 /*
  * Switch the timer base to the current CPU when possible.
  */
-static inline struct hrtimer_base *
-switch_hrtimer_base(struct hrtimer *timer, struct hrtimer_base *base)
+static inline struct hrtimer_clock_base *
+switch_hrtimer_base(struct hrtimer *timer, struct hrtimer_clock_base *base)
 {
-	struct hrtimer_base *new_base;
+	struct hrtimer_clock_base *new_base;
+	struct hrtimer_cpu_base *new_cpu_base;
 
-	new_base = &__get_cpu_var(hrtimer_bases)[base->index];
+	new_cpu_base = &__get_cpu_var(hrtimer_bases);
+	new_base = &new_cpu_base->clock_base[base->index];
 
 	if (base != new_base) {
 		/*
@@ -199,13 +222,13 @@ switch_hrtimer_base(struct hrtimer *timer, struct hrtimer_base *base)
 		 * completed. There is no conflict as we hold the lock until
 		 * the timer is enqueued.
 		 */
-		if (unlikely(base->curr_timer == timer))
+		if (unlikely(hrtimer_callback_running(timer)))
 			return base;
 
 		/* See the comment in lock_timer_base() */
 		timer->base = NULL;
-		spin_unlock(&base->lock);
-		spin_lock(&new_base->lock);
+		spin_unlock(&base->cpu_base->lock);
+		spin_lock(&new_base->cpu_base->lock);
 		timer->base = new_base;
 	}
 	return new_base;
@@ -213,19 +236,17 @@ switch_hrtimer_base(struct hrtimer *timer, struct hrtimer_base *base)
 
 #else /* CONFIG_SMP */
 
-#define set_curr_timer(b, t)		do { } while (0)
-
-static inline struct hrtimer_base *
+static inline struct hrtimer_clock_base *
 lock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags)
 {
-	struct hrtimer_base *base = timer->base;
+	struct hrtimer_clock_base *base = timer->base;
 
-	spin_lock_irqsave(&base->lock, *flags);
+	spin_lock_irqsave(&base->cpu_base->lock, *flags);
 
 	return base;
 }
 
-#define switch_hrtimer_base(t, b)	(b)
+# define switch_hrtimer_base(t, b)	(b)
 
 #endif	/* !CONFIG_SMP */
 
@@ -256,15 +277,12 @@ ktime_t ktime_add_ns(const ktime_t kt, u64 nsec)
 
 	return ktime_add(kt, tmp);
 }
-
-#else /* CONFIG_KTIME_SCALAR */
-
 # endif /* !CONFIG_KTIME_SCALAR */
 
 /*
  * Divide a ktime value by a nanosecond value
  */
-static unsigned long ktime_divns(const ktime_t kt, s64 div)
+unsigned long ktime_divns(const ktime_t kt, s64 div)
 {
 	u64 dclc, inc, dns;
 	int sft = 0;
@@ -281,18 +299,311 @@ static unsigned long ktime_divns(const ktime_t kt, s64 div)
 
 	return (unsigned long) dclc;
 }
-
-#else /* BITS_PER_LONG < 64 */
-# define ktime_divns(kt, div)		(unsigned long)((kt).tv64 / (div))
 #endif /* BITS_PER_LONG >= 64 */
 
+/* High resolution timer related functions */
+#ifdef CONFIG_HIGH_RES_TIMERS
+
+/*
+ * High resolution timer enabled ?
+ */
+static int hrtimer_hres_enabled __read_mostly  = 1;
+
+/*
+ * Enable / Disable high resolution mode
+ */
+static int __init setup_hrtimer_hres(char *str)
+{
+	if (!strcmp(str, "off"))
+		hrtimer_hres_enabled = 0;
+	else if (!strcmp(str, "on"))
+		hrtimer_hres_enabled = 1;
+	else
+		return 0;
+	return 1;
+}
+
+__setup("highres=", setup_hrtimer_hres);
+
+/*
+ * hrtimer_high_res_enabled - query, if the highres mode is enabled
+ */
+static inline int hrtimer_is_hres_enabled(void)
+{
+	return hrtimer_hres_enabled;
+}
+
+/*
+ * Is the high resolution mode active ?
+ */
+static inline int hrtimer_hres_active(void)
+{
+	return __get_cpu_var(hrtimer_bases).hres_active;
+}
+
+/*
+ * Reprogram the event source with checking both queues for the
+ * next event
+ * Called with interrupts disabled and base->lock held
+ */
+static void hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base)
+{
+	int i;
+	struct hrtimer_clock_base *base = cpu_base->clock_base;
+	ktime_t expires;
+
+	cpu_base->expires_next.tv64 = KTIME_MAX;
+
+	for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) {
+		struct hrtimer *timer;
+
+		if (!base->first)
+			continue;
+		timer = rb_entry(base->first, struct hrtimer, node);
+		expires = ktime_sub(timer->expires, base->offset);
+		if (expires.tv64 < cpu_base->expires_next.tv64)
+			cpu_base->expires_next = expires;
+	}
+
+	if (cpu_base->expires_next.tv64 != KTIME_MAX)
+		tick_program_event(cpu_base->expires_next, 1);
+}
+
+/*
+ * Shared reprogramming for clock_realtime and clock_monotonic
+ *
+ * When a timer is enqueued and expires earlier than the already enqueued
+ * timers, we have to check, whether it expires earlier than the timer for
+ * which the clock event device was armed.
+ *
+ * Called with interrupts disabled and base->cpu_base.lock held
+ */
+static int hrtimer_reprogram(struct hrtimer *timer,
+			     struct hrtimer_clock_base *base)
+{
+	ktime_t *expires_next = &__get_cpu_var(hrtimer_bases).expires_next;
+	ktime_t expires = ktime_sub(timer->expires, base->offset);
+	int res;
+
+	/*
+	 * When the callback is running, we do not reprogram the clock event
+	 * device. The timer callback is either running on a different CPU or
+	 * the callback is executed in the hrtimer_interupt context. The
+	 * reprogramming is handled either by the softirq, which called the
+	 * callback or at the end of the hrtimer_interrupt.
+	 */
+	if (hrtimer_callback_running(timer))
+		return 0;
+
+	if (expires.tv64 >= expires_next->tv64)
+		return 0;
+
+	/*
+	 * Clockevents returns -ETIME, when the event was in the past.
+	 */
+	res = tick_program_event(expires, 0);
+	if (!IS_ERR_VALUE(res))
+		*expires_next = expires;
+	return res;
+}
+
+
+/*
+ * Retrigger next event is called after clock was set
+ *
+ * Called with interrupts disabled via on_each_cpu()
+ */
+static void retrigger_next_event(void *arg)
+{
+	struct hrtimer_cpu_base *base;
+	struct timespec realtime_offset;
+	unsigned long seq;
+
+	if (!hrtimer_hres_active())
+		return;
+
+	do {
+		seq = read_seqbegin(&xtime_lock);
+		set_normalized_timespec(&realtime_offset,
+					-wall_to_monotonic.tv_sec,
+					-wall_to_monotonic.tv_nsec);
+	} while (read_seqretry(&xtime_lock, seq));
+
+	base = &__get_cpu_var(hrtimer_bases);
+
+	/* Adjust CLOCK_REALTIME offset */
+	spin_lock(&base->lock);
+	base->clock_base[CLOCK_REALTIME].offset =
+		timespec_to_ktime(realtime_offset);
+
+	hrtimer_force_reprogram(base);
+	spin_unlock(&base->lock);
+}
+
+/*
+ * Clock realtime was set
+ *
+ * Change the offset of the realtime clock vs. the monotonic
+ * clock.
+ *
+ * We might have to reprogram the high resolution timer interrupt. On
+ * SMP we call the architecture specific code to retrigger _all_ high
+ * resolution timer interrupts. On UP we just disable interrupts and
+ * call the high resolution interrupt code.
+ */
+void clock_was_set(void)
+{
+	/* Retrigger the CPU local events everywhere */
+	on_each_cpu(retrigger_next_event, NULL, 0, 1);
+}
+
+/*
+ * Check, whether the timer is on the callback pending list
+ */
+static inline int hrtimer_cb_pending(const struct hrtimer *timer)
+{
+	return timer->state & HRTIMER_STATE_PENDING;
+}
+
+/*
+ * Remove a timer from the callback pending list
+ */
+static inline void hrtimer_remove_cb_pending(struct hrtimer *timer)
+{
+	list_del_init(&timer->cb_entry);
+}
+
+/*
+ * Initialize the high resolution related parts of cpu_base
+ */
+static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base)
+{
+	base->expires_next.tv64 = KTIME_MAX;
+	base->hres_active = 0;
+	INIT_LIST_HEAD(&base->cb_pending);
+}
+
+/*
+ * Initialize the high resolution related parts of a hrtimer
+ */
+static inline void hrtimer_init_timer_hres(struct hrtimer *timer)
+{
+	INIT_LIST_HEAD(&timer->cb_entry);
+}
+
+/*
+ * When High resolution timers are active, try to reprogram. Note, that in case
+ * the state has HRTIMER_STATE_CALLBACK set, no reprogramming and no expiry
+ * check happens. The timer gets enqueued into the rbtree. The reprogramming
+ * and expiry check is done in the hrtimer_interrupt or in the softirq.
+ */
+static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
+					    struct hrtimer_clock_base *base)
+{
+	if (base->cpu_base->hres_active && hrtimer_reprogram(timer, base)) {
+
+		/* Timer is expired, act upon the callback mode */
+		switch(timer->cb_mode) {
+		case HRTIMER_CB_IRQSAFE_NO_RESTART:
+			/*
+			 * We can call the callback from here. No restart
+			 * happens, so no danger of recursion
+			 */
+			BUG_ON(timer->function(timer) != HRTIMER_NORESTART);
+			return 1;
+		case HRTIMER_CB_IRQSAFE_NO_SOFTIRQ:
+			/*
+			 * This is solely for the sched tick emulation with
+			 * dynamic tick support to ensure that we do not
+			 * restart the tick right on the edge and end up with
+			 * the tick timer in the softirq ! The calling site
+			 * takes care of this.
+			 */
+			return 1;
+		case HRTIMER_CB_IRQSAFE:
+		case HRTIMER_CB_SOFTIRQ:
+			/*
+			 * Move everything else into the softirq pending list !
+			 */
+			list_add_tail(&timer->cb_entry,
+				      &base->cpu_base->cb_pending);
+			timer->state = HRTIMER_STATE_PENDING;
+			raise_softirq(HRTIMER_SOFTIRQ);
+			return 1;
+		default:
+			BUG();
+		}
+	}
+	return 0;
+}
+
+/*
+ * Switch to high resolution mode
+ */
+static void hrtimer_switch_to_hres(void)
+{
+	struct hrtimer_cpu_base *base = &__get_cpu_var(hrtimer_bases);
+	unsigned long flags;
+
+	if (base->hres_active)
+		return;
+
+	local_irq_save(flags);
+
+	if (tick_init_highres()) {
+		local_irq_restore(flags);
+		return;
+	}
+	base->hres_active = 1;
+	base->clock_base[CLOCK_REALTIME].resolution = KTIME_HIGH_RES;
+	base->clock_base[CLOCK_MONOTONIC].resolution = KTIME_HIGH_RES;
+
+	tick_setup_sched_timer();
+
+	/* "Retrigger" the interrupt to get things going */
+	retrigger_next_event(NULL);
+	local_irq_restore(flags);
+	printk(KERN_INFO "Switched to high resolution mode on CPU %d\n",
+	       smp_processor_id());
+}
+
+#else
+
+static inline int hrtimer_hres_active(void) { return 0; }
+static inline int hrtimer_is_hres_enabled(void) { return 0; }
+static inline void hrtimer_switch_to_hres(void) { }
+static inline void hrtimer_force_reprogram(struct hrtimer_cpu_base *base) { }
+static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
+					    struct hrtimer_clock_base *base)
+{
+	return 0;
+}
+static inline int hrtimer_cb_pending(struct hrtimer *timer) { return 0; }
+static inline void hrtimer_remove_cb_pending(struct hrtimer *timer) { }
+static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base) { }
+static inline void hrtimer_init_timer_hres(struct hrtimer *timer) { }
+
+#endif /* CONFIG_HIGH_RES_TIMERS */
+
+#ifdef CONFIG_TIMER_STATS
+void __timer_stats_hrtimer_set_start_info(struct hrtimer *timer, void *addr)
+{
+	if (timer->start_site)
+		return;
+
+	timer->start_site = addr;
+	memcpy(timer->start_comm, current->comm, TASK_COMM_LEN);
+	timer->start_pid = current->pid;
+}
+#endif
+
 /*
  * Counterpart to lock_timer_base above:
  */
 static inline
 void unlock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags)
 {
-	spin_unlock_irqrestore(&timer->base->lock, *flags);
+	spin_unlock_irqrestore(&timer->base->cpu_base->lock, *flags);
 }
 
 /**
@@ -342,7 +653,8 @@ hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval)
  * The timer is inserted in expiry order. Insertion into the
  * red black tree is O(log(n)). Must hold the base lock.
  */
-static void enqueue_hrtimer(struct hrtimer *timer, struct hrtimer_base *base)
+static void enqueue_hrtimer(struct hrtimer *timer,
+			    struct hrtimer_clock_base *base, int reprogram)
 {
 	struct rb_node **link = &base->active.rb_node;
 	struct rb_node *parent = NULL;
@@ -368,39 +680,85 @@ static void enqueue_hrtimer(struct hrtimer *timer, struct hrtimer_base *base)
 	 * Insert the timer to the rbtree and check whether it
 	 * replaces the first pending timer
 	 */
-	rb_link_node(&timer->node, parent, link);
-	rb_insert_color(&timer->node, &base->active);
-
 	if (!base->first || timer->expires.tv64 <
-	    rb_entry(base->first, struct hrtimer, node)->expires.tv64)
+	    rb_entry(base->first, struct hrtimer, node)->expires.tv64) {
+		/*
+		 * Reprogram the clock event device. When the timer is already
+		 * expired hrtimer_enqueue_reprogram has either called the
+		 * callback or added it to the pending list and raised the
+		 * softirq.
+		 *
+		 * This is a NOP for !HIGHRES
+		 */
+		if (reprogram && hrtimer_enqueue_reprogram(timer, base))
+			return;
+
 		base->first = &timer->node;
+	}
+
+	rb_link_node(&timer->node, parent, link);
+	rb_insert_color(&timer->node, &base->active);
+	/*
+	 * HRTIMER_STATE_ENQUEUED is or'ed to the current state to preserve the
+	 * state of a possibly running callback.
+	 */
+	timer->state |= HRTIMER_STATE_ENQUEUED;
 }
 
 /*
  * __remove_hrtimer - internal function to remove a timer
  *
  * Caller must hold the base lock.
+ *
+ * High resolution timer mode reprograms the clock event device when the
+ * timer is the one which expires next. The caller can disable this by setting
+ * reprogram to zero. This is useful, when the context does a reprogramming
+ * anyway (e.g. timer interrupt)
  */
-static void __remove_hrtimer(struct hrtimer *timer, struct hrtimer_base *base)
+static void __remove_hrtimer(struct hrtimer *timer,
+			     struct hrtimer_clock_base *base,
+			     unsigned long newstate, int reprogram)
 {
-	/*
-	 * 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);
-	rb_erase(&timer->node, &base->active);
-	rb_set_parent(&timer->node, &timer->node);
+	/* High res. callback list. NOP for !HIGHRES */
+	if (hrtimer_cb_pending(timer))
+		hrtimer_remove_cb_pending(timer);
+	else {
+		/*
+		 * 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);
+		}
+		rb_erase(&timer->node, &base->active);
+	}
+	timer->state = newstate;
 }
 
 /*
  * remove hrtimer, called with base lock held
  */
 static inline int
-remove_hrtimer(struct hrtimer *timer, struct hrtimer_base *base)
+remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base)
 {
-	if (hrtimer_active(timer)) {
-		__remove_hrtimer(timer, base);
+	if (hrtimer_is_queued(timer)) {
+		int reprogram;
+
+		/*
+		 * Remove the timer and force reprogramming when high
+		 * resolution mode is active and the timer is on the current
+		 * CPU. If we remove a timer on another CPU, reprogramming is
+		 * skipped. The interrupt event on this CPU is fired and
+		 * reprogramming happens in the interrupt handler. This is a
+		 * rare case and less expensive than a smp call.
+		 */
+		timer_stats_hrtimer_clear_start_info(timer);
+		reprogram = base->cpu_base == &__get_cpu_var(hrtimer_bases);
+		__remove_hrtimer(timer, base, HRTIMER_STATE_INACTIVE,
+				 reprogram);
 		return 1;
 	}
 	return 0;
@@ -419,7 +777,7 @@ remove_hrtimer(struct hrtimer *timer, struct hrtimer_base *base)
 int
 hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode)
 {
-	struct hrtimer_base *base, *new_base;
+	struct hrtimer_clock_base *base, *new_base;
 	unsigned long flags;
 	int ret;
 
@@ -431,7 +789,7 @@ hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode)
 	/* Switch the timer base, if necessary: */
 	new_base = switch_hrtimer_base(timer, base);
 
-	if (mode == HRTIMER_REL) {
+	if (mode == HRTIMER_MODE_REL) {
 		tim = ktime_add(tim, new_base->get_time());
 		/*
 		 * CONFIG_TIME_LOW_RES is a temporary way for architectures
@@ -446,7 +804,9 @@ hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode)
 	}
 	timer->expires = tim;
 
-	enqueue_hrtimer(timer, new_base);
+	timer_stats_hrtimer_set_start_info(timer);
+
+	enqueue_hrtimer(timer, new_base, base == new_base);
 
 	unlock_hrtimer_base(timer, &flags);
 
@@ -466,13 +826,13 @@ EXPORT_SYMBOL_GPL(hrtimer_start);
  */
 int hrtimer_try_to_cancel(struct hrtimer *timer)
 {
-	struct hrtimer_base *base;
+	struct hrtimer_clock_base *base;
 	unsigned long flags;
 	int ret = -1;
 
 	base = lock_hrtimer_base(timer, &flags);
 
-	if (base->curr_timer != timer)
+	if (!hrtimer_callback_running(timer))
 		ret = remove_hrtimer(timer, base);
 
 	unlock_hrtimer_base(timer, &flags);
@@ -508,19 +868,19 @@ EXPORT_SYMBOL_GPL(hrtimer_cancel);
  */
 ktime_t hrtimer_get_remaining(const struct hrtimer *timer)
 {
-	struct hrtimer_base *base;
+	struct hrtimer_clock_base *base;
 	unsigned long flags;
 	ktime_t rem;
 
 	base = lock_hrtimer_base(timer, &flags);
-	rem = ktime_sub(timer->expires, timer->base->get_time());
+	rem = ktime_sub(timer->expires, base->get_time());
 	unlock_hrtimer_base(timer, &flags);
 
 	return rem;
 }
 EXPORT_SYMBOL_GPL(hrtimer_get_remaining);
 
-#ifdef CONFIG_NO_IDLE_HZ
+#if defined(CONFIG_NO_IDLE_HZ) || defined(CONFIG_NO_HZ)
 /**
  * hrtimer_get_next_event - get the time until next expiry event
  *
@@ -529,26 +889,31 @@ EXPORT_SYMBOL_GPL(hrtimer_get_remaining);
  */
 ktime_t hrtimer_get_next_event(void)
 {
-	struct hrtimer_base *base = __get_cpu_var(hrtimer_bases);
+	struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
+	struct hrtimer_clock_base *base = cpu_base->clock_base;
 	ktime_t delta, mindelta = { .tv64 = KTIME_MAX };
 	unsigned long flags;
 	int i;
 
-	for (i = 0; i < MAX_HRTIMER_BASES; i++, base++) {
-		struct hrtimer *timer;
+	spin_lock_irqsave(&cpu_base->lock, flags);
 
-		spin_lock_irqsave(&base->lock, flags);
-		if (!base->first) {
-			spin_unlock_irqrestore(&base->lock, flags);
-			continue;
+	if (!hrtimer_hres_active()) {
+		for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) {
+			struct hrtimer *timer;
+
+			if (!base->first)
+				continue;
+
+			timer = rb_entry(base->first, struct hrtimer, node);
+			delta.tv64 = timer->expires.tv64;
+			delta = ktime_sub(delta, base->get_time());
+			if (delta.tv64 < mindelta.tv64)
+				mindelta.tv64 = delta.tv64;
 		}
-		timer = rb_entry(base->first, struct hrtimer, node);
-		delta.tv64 = timer->expires.tv64;
-		spin_unlock_irqrestore(&base->lock, flags);
-		delta = ktime_sub(delta, base->get_time());
-		if (delta.tv64 < mindelta.tv64)
-			mindelta.tv64 = delta.tv64;
 	}
+
+	spin_unlock_irqrestore(&cpu_base->lock, flags);
+
 	if (mindelta.tv64 < 0)
 		mindelta.tv64 = 0;
 	return mindelta;
@@ -564,17 +929,23 @@ ktime_t hrtimer_get_next_event(void)
 void hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
 		  enum hrtimer_mode mode)
 {
-	struct hrtimer_base *bases;
+	struct hrtimer_cpu_base *cpu_base;
 
 	memset(timer, 0, sizeof(struct hrtimer));
 
-	bases = __raw_get_cpu_var(hrtimer_bases);
+	cpu_base = &__raw_get_cpu_var(hrtimer_bases);
 
-	if (clock_id == CLOCK_REALTIME && mode != HRTIMER_ABS)
+	if (clock_id == CLOCK_REALTIME && mode != HRTIMER_MODE_ABS)
 		clock_id = CLOCK_MONOTONIC;
 
-	timer->base = &bases[clock_id];
-	rb_set_parent(&timer->node, &timer->node);
+	timer->base = &cpu_base->clock_base[clock_id];
+	hrtimer_init_timer_hres(timer);
+
+#ifdef CONFIG_TIMER_STATS
+	timer->start_site = NULL;
+	timer->start_pid = -1;
+	memset(timer->start_comm, 0, TASK_COMM_LEN);
+#endif
 }
 EXPORT_SYMBOL_GPL(hrtimer_init);
 
@@ -588,21 +959,159 @@ EXPORT_SYMBOL_GPL(hrtimer_init);
  */
 int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp)
 {
-	struct hrtimer_base *bases;
+	struct hrtimer_cpu_base *cpu_base;
 
-	bases = __raw_get_cpu_var(hrtimer_bases);
-	*tp = ktime_to_timespec(bases[which_clock].resolution);
+	cpu_base = &__raw_get_cpu_var(hrtimer_bases);
+	*tp = ktime_to_timespec(cpu_base->clock_base[which_clock].resolution);
 
 	return 0;
 }
 EXPORT_SYMBOL_GPL(hrtimer_get_res);
 
+#ifdef CONFIG_HIGH_RES_TIMERS
+
+/*
+ * High resolution timer interrupt
+ * Called with interrupts disabled
+ */
+void hrtimer_interrupt(struct clock_event_device *dev)
+{
+	struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
+	struct hrtimer_clock_base *base;
+	ktime_t expires_next, now;
+	int i, raise = 0;
+
+	BUG_ON(!cpu_base->hres_active);
+	cpu_base->nr_events++;
+	dev->next_event.tv64 = KTIME_MAX;
+
+ retry:
+	now = ktime_get();
+
+	expires_next.tv64 = KTIME_MAX;
+
+	base = cpu_base->clock_base;
+
+	for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
+		ktime_t basenow;
+		struct rb_node *node;
+
+		spin_lock(&cpu_base->lock);
+
+		basenow = ktime_add(now, base->offset);
+
+		while ((node = base->first)) {
+			struct hrtimer *timer;
+
+			timer = rb_entry(node, struct hrtimer, node);
+
+			if (basenow.tv64 < timer->expires.tv64) {
+				ktime_t expires;
+
+				expires = ktime_sub(timer->expires,
+						    base->offset);
+				if (expires.tv64 < expires_next.tv64)
+					expires_next = expires;
+				break;
+			}
+
+			/* Move softirq callbacks to the pending list */
+			if (timer->cb_mode == HRTIMER_CB_SOFTIRQ) {
+				__remove_hrtimer(timer, base,
+						 HRTIMER_STATE_PENDING, 0);
+				list_add_tail(&timer->cb_entry,
+					      &base->cpu_base->cb_pending);
+				raise = 1;
+				continue;
+			}
+
+			__remove_hrtimer(timer, base,
+					 HRTIMER_STATE_CALLBACK, 0);
+			timer_stats_account_hrtimer(timer);
+
+			/*
+			 * Note: We clear the CALLBACK bit after
+			 * enqueue_hrtimer to avoid reprogramming of
+			 * the event hardware. This happens at the end
+			 * of this function anyway.
+			 */
+			if (timer->function(timer) != HRTIMER_NORESTART) {
+				BUG_ON(timer->state != HRTIMER_STATE_CALLBACK);
+				enqueue_hrtimer(timer, base, 0);
+			}
+			timer->state &= ~HRTIMER_STATE_CALLBACK;
+		}
+		spin_unlock(&cpu_base->lock);
+		base++;
+	}
+
+	cpu_base->expires_next = expires_next;
+
+	/* Reprogramming necessary ? */
+	if (expires_next.tv64 != KTIME_MAX) {
+		if (tick_program_event(expires_next, 0))
+			goto retry;
+	}
+
+	/* Raise softirq ? */
+	if (raise)
+		raise_softirq(HRTIMER_SOFTIRQ);
+}
+
+static void run_hrtimer_softirq(struct softirq_action *h)
+{
+	struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
+
+	spin_lock_irq(&cpu_base->lock);
+
+	while (!list_empty(&cpu_base->cb_pending)) {
+		enum hrtimer_restart (*fn)(struct hrtimer *);
+		struct hrtimer *timer;
+		int restart;
+
+		timer = list_entry(cpu_base->cb_pending.next,
+				   struct hrtimer, cb_entry);
+
+		timer_stats_account_hrtimer(timer);
+
+		fn = timer->function;
+		__remove_hrtimer(timer, timer->base, HRTIMER_STATE_CALLBACK, 0);
+		spin_unlock_irq(&cpu_base->lock);
+
+		restart = fn(timer);
+
+		spin_lock_irq(&cpu_base->lock);
+
+		timer->state &= ~HRTIMER_STATE_CALLBACK;
+		if (restart == HRTIMER_RESTART) {
+			BUG_ON(hrtimer_active(timer));
+			/*
+			 * Enqueue the timer, allow reprogramming of the event
+			 * device
+			 */
+			enqueue_hrtimer(timer, timer->base, 1);
+		} else if (hrtimer_active(timer)) {
+			/*
+			 * If the timer was rearmed on another CPU, reprogram
+			 * the event device.
+			 */
+			if (timer->base->first == &timer->node)
+				hrtimer_reprogram(timer, timer->base);
+		}
+	}
+	spin_unlock_irq(&cpu_base->lock);
+}
+
+#endif	/* CONFIG_HIGH_RES_TIMERS */
+
 /*
  * Expire the per base hrtimer-queue:
  */
-static inline void run_hrtimer_queue(struct hrtimer_base *base)
+static inline void run_hrtimer_queue(struct hrtimer_cpu_base *cpu_base,
+				     int index)
 {
 	struct rb_node *node;
+	struct hrtimer_clock_base *base = &cpu_base->clock_base[index];
 
 	if (!base->first)
 		return;
@@ -610,53 +1119,72 @@ static inline void run_hrtimer_queue(struct hrtimer_base *base)
 	if (base->get_softirq_time)
 		base->softirq_time = base->get_softirq_time();
 
-	spin_lock_irq(&base->lock);
+	spin_lock_irq(&cpu_base->lock);
 
 	while ((node = base->first)) {
 		struct hrtimer *timer;
-		int (*fn)(struct hrtimer *);
+		enum hrtimer_restart (*fn)(struct hrtimer *);
 		int restart;
 
 		timer = rb_entry(node, struct hrtimer, node);
 		if (base->softirq_time.tv64 <= timer->expires.tv64)
 			break;
 
+		timer_stats_account_hrtimer(timer);
+
 		fn = timer->function;
-		set_curr_timer(base, timer);
-		__remove_hrtimer(timer, base);
-		spin_unlock_irq(&base->lock);
+		__remove_hrtimer(timer, base, HRTIMER_STATE_CALLBACK, 0);
+		spin_unlock_irq(&cpu_base->lock);
 
 		restart = fn(timer);
 
-		spin_lock_irq(&base->lock);
+		spin_lock_irq(&cpu_base->lock);
 
+		timer->state &= ~HRTIMER_STATE_CALLBACK;
 		if (restart != HRTIMER_NORESTART) {
 			BUG_ON(hrtimer_active(timer));
-			enqueue_hrtimer(timer, base);
+			enqueue_hrtimer(timer, base, 0);
 		}
 	}
-	set_curr_timer(base, NULL);
-	spin_unlock_irq(&base->lock);
+	spin_unlock_irq(&cpu_base->lock);
 }
 
 /*
  * Called from timer softirq every jiffy, expire hrtimers:
+ *
+ * For HRT its the fall back code to run the softirq in the timer
+ * softirq context in case the hrtimer initialization failed or has
+ * not been done yet.
  */
 void hrtimer_run_queues(void)
 {
-	struct hrtimer_base *base = __get_cpu_var(hrtimer_bases);
+	struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
 	int i;
 
-	hrtimer_get_softirq_time(base);
+	if (hrtimer_hres_active())
+		return;
+
+	/*
+	 * This _is_ ugly: We have to check in the softirq context,
+	 * whether we can switch to highres and / or nohz mode. The
+	 * clocksource switch happens in the timer interrupt with
+	 * xtime_lock held. Notification from there only sets the
+	 * check bit in the tick_oneshot code, otherwise we might
+	 * deadlock vs. xtime_lock.
+	 */
+	if (tick_check_oneshot_change(!hrtimer_is_hres_enabled()))
+		hrtimer_switch_to_hres();
 
-	for (i = 0; i < MAX_HRTIMER_BASES; i++)
-		run_hrtimer_queue(&base[i]);
+	hrtimer_get_softirq_time(cpu_base);
+
+	for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++)
+		run_hrtimer_queue(cpu_base, i);
 }
 
 /*
  * Sleep related functions:
  */
-static int hrtimer_wakeup(struct hrtimer *timer)
+static enum hrtimer_restart hrtimer_wakeup(struct hrtimer *timer)
 {
 	struct hrtimer_sleeper *t =
 		container_of(timer, struct hrtimer_sleeper, timer);
@@ -673,6 +1201,9 @@ void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *task)
 {
 	sl->timer.function = hrtimer_wakeup;
 	sl->task = task;
+#ifdef CONFIG_HIGH_RES_TIMERS
+	sl->timer.cb_mode = HRTIMER_CB_IRQSAFE_NO_RESTART;
+#endif
 }
 
 static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mode)
@@ -683,10 +1214,11 @@ static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mod
 		set_current_state(TASK_INTERRUPTIBLE);
 		hrtimer_start(&t->timer, t->timer.expires, mode);
 
-		schedule();
+		if (likely(t->task))
+			schedule();
 
 		hrtimer_cancel(&t->timer);
-		mode = HRTIMER_ABS;
+		mode = HRTIMER_MODE_ABS;
 
 	} while (t->task && !signal_pending(current));
 
@@ -702,10 +1234,10 @@ long __sched hrtimer_nanosleep_restart(struct restart_block *restart)
 
 	restart->fn = do_no_restart_syscall;
 
-	hrtimer_init(&t.timer, restart->arg0, HRTIMER_ABS);
+	hrtimer_init(&t.timer, restart->arg0, HRTIMER_MODE_ABS);
 	t.timer.expires.tv64 = ((u64)restart->arg3 << 32) | (u64) restart->arg2;
 
-	if (do_nanosleep(&t, HRTIMER_ABS))
+	if (do_nanosleep(&t, HRTIMER_MODE_ABS))
 		return 0;
 
 	rmtp = (struct timespec __user *) restart->arg1;
@@ -738,7 +1270,7 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
 		return 0;
 
 	/* Absolute timers do not update the rmtp value and restart: */
-	if (mode == HRTIMER_ABS)
+	if (mode == HRTIMER_MODE_ABS)
 		return -ERESTARTNOHAND;
 
 	if (rmtp) {
@@ -771,7 +1303,7 @@ sys_nanosleep(struct timespec __user *rqtp, struct timespec __user *rmtp)
 	if (!timespec_valid(&tu))
 		return -EINVAL;
 
-	return hrtimer_nanosleep(&tu, rmtp, HRTIMER_REL, CLOCK_MONOTONIC);
+	return hrtimer_nanosleep(&tu, rmtp, HRTIMER_MODE_REL, CLOCK_MONOTONIC);
 }
 
 /*
@@ -779,56 +1311,60 @@ sys_nanosleep(struct timespec __user *rqtp, struct timespec __user *rmtp)
  */
 static void __devinit init_hrtimers_cpu(int cpu)
 {
-	struct hrtimer_base *base = per_cpu(hrtimer_bases, cpu);
+	struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu);
 	int i;
 
-	for (i = 0; i < MAX_HRTIMER_BASES; i++, base++) {
-		spin_lock_init(&base->lock);
-		lockdep_set_class(&base->lock, &base->lock_key);
-	}
+	spin_lock_init(&cpu_base->lock);
+	lockdep_set_class(&cpu_base->lock, &cpu_base->lock_key);
+
+	for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++)
+		cpu_base->clock_base[i].cpu_base = cpu_base;
+
+	hrtimer_init_hres(cpu_base);
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
 
-static void migrate_hrtimer_list(struct hrtimer_base *old_base,
-				struct hrtimer_base *new_base)
+static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base,
+				struct hrtimer_clock_base *new_base)
 {
 	struct hrtimer *timer;
 	struct rb_node *node;
 
 	while ((node = rb_first(&old_base->active))) {
 		timer = rb_entry(node, struct hrtimer, node);
-		__remove_hrtimer(timer, old_base);
+		BUG_ON(hrtimer_callback_running(timer));
+		__remove_hrtimer(timer, old_base, HRTIMER_STATE_INACTIVE, 0);
 		timer->base = new_base;
-		enqueue_hrtimer(timer, new_base);
+		/*
+		 * Enqueue the timer. Allow reprogramming of the event device
+		 */
+		enqueue_hrtimer(timer, new_base, 1);
 	}
 }
 
 static void migrate_hrtimers(int cpu)
 {
-	struct hrtimer_base *old_base, *new_base;
+	struct hrtimer_cpu_base *old_base, *new_base;
 	int i;
 
 	BUG_ON(cpu_online(cpu));
-	old_base = per_cpu(hrtimer_bases, cpu);
-	new_base = get_cpu_var(hrtimer_bases);
-
-	local_irq_disable();
+	old_base = &per_cpu(hrtimer_bases, cpu);
+	new_base = &get_cpu_var(hrtimer_bases);
 
-	for (i = 0; i < MAX_HRTIMER_BASES; i++) {
+	tick_cancel_sched_timer(cpu);
 
-		spin_lock(&new_base->lock);
-		spin_lock(&old_base->lock);
-
-		BUG_ON(old_base->curr_timer);
+	local_irq_disable();
 
-		migrate_hrtimer_list(old_base, new_base);
+	spin_lock(&new_base->lock);
+	spin_lock(&old_base->lock);
 
-		spin_unlock(&old_base->lock);
-		spin_unlock(&new_base->lock);
-		old_base++;
-		new_base++;
+	for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
+		migrate_hrtimer_list(&old_base->clock_base[i],
+				     &new_base->clock_base[i]);
 	}
+	spin_unlock(&old_base->lock);
+	spin_unlock(&new_base->lock);
 
 	local_irq_enable();
 	put_cpu_var(hrtimer_bases);
@@ -848,6 +1384,7 @@ static int __cpuinit hrtimer_cpu_notify(struct notifier_block *self,
 
 #ifdef CONFIG_HOTPLUG_CPU
 	case CPU_DEAD:
+		clockevents_notify(CLOCK_EVT_NOTIFY_CPU_DEAD, &cpu);
 		migrate_hrtimers(cpu);
 		break;
 #endif
@@ -868,5 +1405,8 @@ void __init hrtimers_init(void)
 	hrtimer_cpu_notify(&hrtimers_nb, (unsigned long)CPU_UP_PREPARE,
 			  (void *)(long)smp_processor_id());
 	register_cpu_notifier(&hrtimers_nb);
+#ifdef CONFIG_HIGH_RES_TIMERS
+	open_softirq(HRTIMER_SOFTIRQ, run_hrtimer_softirq, NULL);
+#endif
 }
 
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 475e8a71bcd..0133f4f9e9f 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -168,7 +168,7 @@ EXPORT_SYMBOL(set_irq_data);
 /**
  *	set_irq_data - set irq type data for an irq
  *	@irq:	Interrupt number
- *	@data:	Pointer to interrupt specific data
+ *	@entry:	Pointer to MSI descriptor data
  *
  *	Set the hardware irq controller data for an irq
  */
@@ -230,10 +230,6 @@ static void default_enable(unsigned int irq)
  */
 static void default_disable(unsigned int irq)
 {
-	struct irq_desc *desc = irq_desc + irq;
-
-	if (!(desc->status & IRQ_DELAYED_DISABLE))
-		desc->chip->mask(irq);
 }
 
 /*
@@ -298,13 +294,18 @@ handle_simple_irq(unsigned int irq, struct irq_desc *desc)
 
 	if (unlikely(desc->status & IRQ_INPROGRESS))
 		goto out_unlock;
-	desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
 	kstat_cpu(cpu).irqs[irq]++;
 
 	action = desc->action;
-	if (unlikely(!action || (desc->status & IRQ_DISABLED)))
+	if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
+		if (desc->chip->mask)
+			desc->chip->mask(irq);
+		desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
+		desc->status |= IRQ_PENDING;
 		goto out_unlock;
+	}
 
+	desc->status &= ~(IRQ_REPLAY | IRQ_WAITING | IRQ_PENDING);
 	desc->status |= IRQ_INPROGRESS;
 	spin_unlock(&desc->lock);
 
@@ -396,11 +397,13 @@ handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
 
 	/*
 	 * If its disabled or no action available
-	 * keep it masked and get out of here
+	 * then mask it and get out of here:
 	 */
 	action = desc->action;
 	if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
 		desc->status |= IRQ_PENDING;
+		if (desc->chip->mask)
+			desc->chip->mask(irq);
 		goto out;
 	}
 
@@ -562,10 +565,8 @@ __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
 
 	/* Uninstall? */
 	if (handle == handle_bad_irq) {
-		if (desc->chip != &no_irq_chip) {
-			desc->chip->mask(irq);
-			desc->chip->ack(irq);
-		}
+		if (desc->chip != &no_irq_chip)
+			mask_ack_irq(desc, irq);
 		desc->status |= IRQ_DISABLED;
 		desc->depth = 1;
 	}
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 7c85d69188e..5597c157442 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -38,6 +38,46 @@ void synchronize_irq(unsigned int irq)
 }
 EXPORT_SYMBOL(synchronize_irq);
 
+/**
+ *	irq_can_set_affinity - Check if the affinity of a given irq can be set
+ *	@irq:		Interrupt to check
+ *
+ */
+int irq_can_set_affinity(unsigned int irq)
+{
+	struct irq_desc *desc = irq_desc + irq;
+
+	if (CHECK_IRQ_PER_CPU(desc->status) || !desc->chip ||
+	    !desc->chip->set_affinity)
+		return 0;
+
+	return 1;
+}
+
+/**
+ *	irq_set_affinity - Set the irq affinity of a given irq
+ *	@irq:		Interrupt to set affinity
+ *	@cpumask:	cpumask
+ *
+ */
+int irq_set_affinity(unsigned int irq, cpumask_t cpumask)
+{
+	struct irq_desc *desc = irq_desc + irq;
+
+	if (!desc->chip->set_affinity)
+		return -EINVAL;
+
+	set_balance_irq_affinity(irq, cpumask);
+
+#ifdef CONFIG_GENERIC_PENDING_IRQ
+	set_pending_irq(irq, cpumask);
+#else
+	desc->affinity = cpumask;
+	desc->chip->set_affinity(irq, cpumask);
+#endif
+	return 0;
+}
+
 #endif
 
 /**
@@ -281,6 +321,10 @@ int setup_irq(unsigned int irq, struct irqaction *new)
 	if (new->flags & IRQF_PERCPU)
 		desc->status |= IRQ_PER_CPU;
 #endif
+	/* Exclude IRQ from balancing */
+	if (new->flags & IRQF_NOBALANCING)
+		desc->status |= IRQ_NO_BALANCING;
+
 	if (!shared) {
 		irq_chip_set_defaults(desc->chip);
 
@@ -461,7 +505,7 @@ int request_irq(unsigned int irq, irq_handler_t handler,
 	/*
 	 * Lockdep wants atomic interrupt handlers:
 	 */
-	irqflags |= SA_INTERRUPT;
+	irqflags |= IRQF_DISABLED;
 #endif
 	/*
 	 * Sanity-check: shared interrupts must pass in a real dev-ID,
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
index 6d3be06e8ce..2db91eb54ad 100644
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -16,26 +16,6 @@ static struct proc_dir_entry *root_irq_dir;
 
 #ifdef CONFIG_SMP
 
-#ifdef CONFIG_GENERIC_PENDING_IRQ
-void proc_set_irq_affinity(unsigned int irq, cpumask_t mask_val)
-{
-	set_balance_irq_affinity(irq, mask_val);
-
-	/*
-	 * Save these away for later use. Re-progam when the
-	 * interrupt is pending
-	 */
-	set_pending_irq(irq, mask_val);
-}
-#else
-void proc_set_irq_affinity(unsigned int irq, cpumask_t mask_val)
-{
-	set_balance_irq_affinity(irq, mask_val);
-	irq_desc[irq].affinity = mask_val;
-	irq_desc[irq].chip->set_affinity(irq, mask_val);
-}
-#endif
-
 static int irq_affinity_read_proc(char *page, char **start, off_t off,
 				  int count, int *eof, void *data)
 {
@@ -55,7 +35,7 @@ static int irq_affinity_write_proc(struct file *file, const char __user *buffer,
 	cpumask_t new_value, tmp;
 
 	if (!irq_desc[irq].chip->set_affinity || no_irq_affinity ||
-				CHECK_IRQ_PER_CPU(irq_desc[irq].status))
+	    irq_balancing_disabled(irq))
 		return -EIO;
 
 	err = cpumask_parse_user(buffer, count, new_value);
@@ -73,7 +53,7 @@ static int irq_affinity_write_proc(struct file *file, const char __user *buffer,
 		   code to set default SMP affinity. */
 		return select_smp_affinity(irq) ? -EINVAL : full_count;
 
-	proc_set_irq_affinity(irq, new_value);
+	irq_set_affinity(irq, new_value);
 
 	return full_count;
 }
diff --git a/kernel/itimer.c b/kernel/itimer.c
index 204ed7939e7..307c6a632ef 100644
--- a/kernel/itimer.c
+++ b/kernel/itimer.c
@@ -128,18 +128,13 @@ asmlinkage long sys_getitimer(int which, struct itimerval __user *value)
 /*
  * The timer is automagically restarted, when interval != 0
  */
-int it_real_fn(struct hrtimer *timer)
+enum hrtimer_restart it_real_fn(struct hrtimer *timer)
 {
 	struct signal_struct *sig =
 	    container_of(timer, struct signal_struct, real_timer);
 
 	send_group_sig_info(SIGALRM, SEND_SIG_PRIV, sig->tsk);
 
-	if (sig->it_real_incr.tv64 != 0) {
-		hrtimer_forward(timer, timer->base->softirq_time,
-				sig->it_real_incr);
-		return HRTIMER_RESTART;
-	}
 	return HRTIMER_NORESTART;
 }
 
@@ -231,11 +226,14 @@ again:
 			spin_unlock_irq(&tsk->sighand->siglock);
 			goto again;
 		}
-		tsk->signal->it_real_incr =
-			timeval_to_ktime(value->it_interval);
 		expires = timeval_to_ktime(value->it_value);
-		if (expires.tv64 != 0)
-			hrtimer_start(timer, expires, HRTIMER_REL);
+		if (expires.tv64 != 0) {
+			tsk->signal->it_real_incr =
+				timeval_to_ktime(value->it_interval);
+			hrtimer_start(timer, expires, HRTIMER_MODE_REL);
+		} else
+			tsk->signal->it_real_incr.tv64 = 0;
+
 		spin_unlock_irq(&tsk->sighand->siglock);
 		break;
 	case ITIMER_VIRTUAL:
diff --git a/kernel/kmod.c b/kernel/kmod.c
index 3a7379aa31c..796276141e5 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -217,7 +217,10 @@ static int wait_for_helper(void *data)
 			sub_info->retval = ret;
 	}
 
-	complete(sub_info->complete);
+	if (sub_info->wait < 0)
+		kfree(sub_info);
+	else
+		complete(sub_info->complete);
 	return 0;
 }
 
@@ -239,6 +242,9 @@ static void __call_usermodehelper(struct work_struct *work)
 		pid = kernel_thread(____call_usermodehelper, sub_info,
 				    CLONE_VFORK | SIGCHLD);
 
+	if (wait < 0)
+		return;
+
 	if (pid < 0) {
 		sub_info->retval = pid;
 		complete(sub_info->complete);
@@ -253,6 +259,9 @@ static void __call_usermodehelper(struct work_struct *work)
  * @envp: null-terminated environment list
  * @session_keyring: session keyring for process (NULL for an empty keyring)
  * @wait: wait for the application to finish and return status.
+ *        when -1 don't wait at all, but you get no useful error back when
+ *        the program couldn't be exec'ed. This makes it safe to call
+ *        from interrupt context.
  *
  * Runs a user-space application.  The application is started
  * asynchronously if wait is not set, and runs as a child of keventd.
@@ -265,17 +274,8 @@ int call_usermodehelper_keys(char *path, char **argv, char **envp,
 			     struct key *session_keyring, int wait)
 {
 	DECLARE_COMPLETION_ONSTACK(done);
-	struct subprocess_info sub_info = {
-		.work		= __WORK_INITIALIZER(sub_info.work,
-						     __call_usermodehelper),
-		.complete	= &done,
-		.path		= path,
-		.argv		= argv,
-		.envp		= envp,
-		.ring		= session_keyring,
-		.wait		= wait,
-		.retval		= 0,
-	};
+	struct subprocess_info *sub_info;
+	int retval;
 
 	if (!khelper_wq)
 		return -EBUSY;
@@ -283,9 +283,25 @@ int call_usermodehelper_keys(char *path, char **argv, char **envp,
 	if (path[0] == '\0')
 		return 0;
 
-	queue_work(khelper_wq, &sub_info.work);
+	sub_info = kzalloc(sizeof(struct subprocess_info),  GFP_ATOMIC);
+	if (!sub_info)
+		return -ENOMEM;
+
+	INIT_WORK(&sub_info->work, __call_usermodehelper);
+	sub_info->complete = &done;
+	sub_info->path = path;
+	sub_info->argv = argv;
+	sub_info->envp = envp;
+	sub_info->ring = session_keyring;
+	sub_info->wait = wait;
+
+	queue_work(khelper_wq, &sub_info->work);
+	if (wait < 0) /* task has freed sub_info */
+		return 0;
 	wait_for_completion(&done);
-	return sub_info.retval;
+	retval = sub_info->retval;
+	kfree(sub_info);
+	return retval;
 }
 EXPORT_SYMBOL(call_usermodehelper_keys);
 
diff --git a/kernel/lockdep_proc.c b/kernel/lockdep_proc.c
index 88fc611b3ae..58f35e586ee 100644
--- a/kernel/lockdep_proc.c
+++ b/kernel/lockdep_proc.c
@@ -10,7 +10,6 @@
  * Code for /proc/lockdep and /proc/lockdep_stats:
  *
  */
-#include <linux/sched.h>
 #include <linux/module.h>
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
diff --git a/kernel/mutex-debug.c b/kernel/mutex-debug.c
index 841539d72c5..d17436cdea1 100644
--- a/kernel/mutex-debug.c
+++ b/kernel/mutex-debug.c
@@ -13,7 +13,6 @@
  *  Released under the General Public License (GPL).
  */
 #include <linux/mutex.h>
-#include <linux/sched.h>
 #include <linux/delay.h>
 #include <linux/module.h>
 #include <linux/poison.h>
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index 7c3e1e6dfb5..657f7769741 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -304,7 +304,7 @@ int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *tp)
 		 * should be able to see it.
 		 */
 		struct task_struct *p;
-		read_lock(&tasklist_lock);
+		rcu_read_lock();
 		p = find_task_by_pid(pid);
 		if (p) {
 			if (CPUCLOCK_PERTHREAD(which_clock)) {
@@ -312,12 +312,17 @@ int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *tp)
 					error = cpu_clock_sample(which_clock,
 								 p, &rtn);
 				}
-			} else if (p->tgid == pid && p->signal) {
-				error = cpu_clock_sample_group(which_clock,
-							       p, &rtn);
+			} else {
+				read_lock(&tasklist_lock);
+				if (p->tgid == pid && p->signal) {
+					error =
+					    cpu_clock_sample_group(which_clock,
+							           p, &rtn);
+				}
+				read_unlock(&tasklist_lock);
 			}
 		}
-		read_unlock(&tasklist_lock);
+		rcu_read_unlock();
 	}
 
 	if (error)
diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
index a1bf6161783..44318ca7197 100644
--- a/kernel/posix-timers.c
+++ b/kernel/posix-timers.c
@@ -145,7 +145,7 @@ static int common_timer_set(struct k_itimer *, int,
 			    struct itimerspec *, struct itimerspec *);
 static int common_timer_del(struct k_itimer *timer);
 
-static int posix_timer_fn(struct hrtimer *data);
+static enum hrtimer_restart posix_timer_fn(struct hrtimer *data);
 
 static struct k_itimer *lock_timer(timer_t timer_id, unsigned long *flags);
 
@@ -334,12 +334,12 @@ EXPORT_SYMBOL_GPL(posix_timer_event);
 
  * This code is for CLOCK_REALTIME* and CLOCK_MONOTONIC* timers.
  */
-static int posix_timer_fn(struct hrtimer *timer)
+static enum hrtimer_restart posix_timer_fn(struct hrtimer *timer)
 {
 	struct k_itimer *timr;
 	unsigned long flags;
 	int si_private = 0;
-	int ret = HRTIMER_NORESTART;
+	enum hrtimer_restart ret = HRTIMER_NORESTART;
 
 	timr = container_of(timer, struct k_itimer, it.real.timer);
 	spin_lock_irqsave(&timr->it_lock, flags);
@@ -356,7 +356,7 @@ static int posix_timer_fn(struct hrtimer *timer)
 		if (timr->it.real.interval.tv64 != 0) {
 			timr->it_overrun +=
 				hrtimer_forward(timer,
-						timer->base->softirq_time,
+						hrtimer_cb_get_time(timer),
 						timr->it.real.interval);
 			ret = HRTIMER_RESTART;
 			++timr->it_requeue_pending;
@@ -722,7 +722,7 @@ common_timer_set(struct k_itimer *timr, int flags,
 	if (!new_setting->it_value.tv_sec && !new_setting->it_value.tv_nsec)
 		return 0;
 
-	mode = flags & TIMER_ABSTIME ? HRTIMER_ABS : HRTIMER_REL;
+	mode = flags & TIMER_ABSTIME ? HRTIMER_MODE_ABS : HRTIMER_MODE_REL;
 	hrtimer_init(&timr->it.real.timer, timr->it_clock, mode);
 	timr->it.real.timer.function = posix_timer_fn;
 
@@ -734,7 +734,7 @@ common_timer_set(struct k_itimer *timr, int flags,
 	/* SIGEV_NONE timers are not queued ! See common_timer_get */
 	if (((timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE)) {
 		/* Setup correct expiry time for relative timers */
-		if (mode == HRTIMER_REL)
+		if (mode == HRTIMER_MODE_REL)
 			timer->expires = ktime_add(timer->expires,
 						   timer->base->get_time());
 		return 0;
@@ -950,7 +950,8 @@ static int common_nsleep(const clockid_t which_clock, int flags,
 			 struct timespec *tsave, struct timespec __user *rmtp)
 {
 	return hrtimer_nanosleep(tsave, rmtp, flags & TIMER_ABSTIME ?
-				 HRTIMER_ABS : HRTIMER_REL, which_clock);
+				 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
+				 which_clock);
 }
 
 asmlinkage long
diff --git a/kernel/resource.c b/kernel/resource.c
index 2a3f8863658..bdb55a33f96 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -8,7 +8,6 @@
  */
 
 #include <linux/module.h>
-#include <linux/sched.h>
 #include <linux/errno.h>
 #include <linux/ioport.h>
 #include <linux/init.h>
diff --git a/kernel/rtmutex.c b/kernel/rtmutex.c
index 4ab17da46fd..180978cb2f7 100644
--- a/kernel/rtmutex.c
+++ b/kernel/rtmutex.c
@@ -625,7 +625,7 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state,
 	/* Setup the timer, when timeout != NULL */
 	if (unlikely(timeout))
 		hrtimer_start(&timeout->timer, timeout->timer.expires,
-			      HRTIMER_ABS);
+			      HRTIMER_MODE_ABS);
 
 	for (;;) {
 		/* Try to acquire the lock: */
diff --git a/kernel/sched.c b/kernel/sched.c
index 08f86178aa3..0dc757246d8 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1853,6 +1853,13 @@ context_switch(struct rq *rq, struct task_struct *prev,
 	struct mm_struct *mm = next->mm;
 	struct mm_struct *oldmm = prev->active_mm;
 
+	/*
+	 * For paravirt, this is coupled with an exit in switch_to to
+	 * combine the page table reload and the switch backend into
+	 * one hypercall.
+	 */
+	arch_enter_lazy_cpu_mode();
+
 	if (!mm) {
 		next->active_mm = oldmm;
 		atomic_inc(&oldmm->mm_count);
diff --git a/kernel/signal.c b/kernel/signal.c
index 8072e568bbe..e2a7d4bf7d5 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -456,26 +456,50 @@ static int __dequeue_signal(struct sigpending *pending, sigset_t *mask,
 int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
 {
 	int signr = __dequeue_signal(&tsk->pending, mask, info);
-	if (!signr)
+	if (!signr) {
 		signr = __dequeue_signal(&tsk->signal->shared_pending,
 					 mask, info);
+		/*
+		 * itimer signal ?
+		 *
+		 * itimers are process shared and we restart periodic
+		 * itimers in the signal delivery path to prevent DoS
+		 * attacks in the high resolution timer case. This is
+		 * compliant with the old way of self restarting
+		 * itimers, as the SIGALRM is a legacy signal and only
+		 * queued once. Changing the restart behaviour to
+		 * restart the timer in the signal dequeue path is
+		 * reducing the timer noise on heavy loaded !highres
+		 * systems too.
+		 */
+		if (unlikely(signr == SIGALRM)) {
+			struct hrtimer *tmr = &tsk->signal->real_timer;
+
+			if (!hrtimer_is_queued(tmr) &&
+			    tsk->signal->it_real_incr.tv64 != 0) {
+				hrtimer_forward(tmr, tmr->base->get_time(),
+						tsk->signal->it_real_incr);
+				hrtimer_restart(tmr);
+			}
+		}
+	}
 	recalc_sigpending_tsk(tsk);
- 	if (signr && unlikely(sig_kernel_stop(signr))) {
- 		/*
- 		 * Set a marker that we have dequeued a stop signal.  Our
- 		 * caller might release the siglock and then the pending
- 		 * stop signal it is about to process is no longer in the
- 		 * pending bitmasks, but must still be cleared by a SIGCONT
- 		 * (and overruled by a SIGKILL).  So those cases clear this
- 		 * shared flag after we've set it.  Note that this flag may
- 		 * remain set after the signal we return is ignored or
- 		 * handled.  That doesn't matter because its only purpose
- 		 * is to alert stop-signal processing code when another
- 		 * processor has come along and cleared the flag.
- 		 */
- 		if (!(tsk->signal->flags & SIGNAL_GROUP_EXIT))
- 			tsk->signal->flags |= SIGNAL_STOP_DEQUEUED;
- 	}
+	if (signr && unlikely(sig_kernel_stop(signr))) {
+		/*
+		 * Set a marker that we have dequeued a stop signal.  Our
+		 * caller might release the siglock and then the pending
+		 * stop signal it is about to process is no longer in the
+		 * pending bitmasks, but must still be cleared by a SIGCONT
+		 * (and overruled by a SIGKILL).  So those cases clear this
+		 * shared flag after we've set it.  Note that this flag may
+		 * remain set after the signal we return is ignored or
+		 * handled.  That doesn't matter because its only purpose
+		 * is to alert stop-signal processing code when another
+		 * processor has come along and cleared the flag.
+		 */
+		if (!(tsk->signal->flags & SIGNAL_GROUP_EXIT))
+			tsk->signal->flags |= SIGNAL_STOP_DEQUEUED;
+	}
 	if ( signr &&
 	     ((info->si_code & __SI_MASK) == __SI_TIMER) &&
 	     info->si_sys_private){
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 918e52df090..8b75008e2bd 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -17,6 +17,7 @@
 #include <linux/kthread.h>
 #include <linux/rcupdate.h>
 #include <linux/smp.h>
+#include <linux/tick.h>
 
 #include <asm/irq.h>
 /*
@@ -273,6 +274,18 @@ EXPORT_SYMBOL(do_softirq);
 
 #endif
 
+/*
+ * Enter an interrupt context.
+ */
+void irq_enter(void)
+{
+	__irq_enter();
+#ifdef CONFIG_NO_HZ
+	if (idle_cpu(smp_processor_id()))
+		tick_nohz_update_jiffies();
+#endif
+}
+
 #ifdef __ARCH_IRQ_EXIT_IRQS_DISABLED
 # define invoke_softirq()	__do_softirq()
 #else
@@ -289,6 +302,12 @@ void irq_exit(void)
 	sub_preempt_count(IRQ_EXIT_OFFSET);
 	if (!in_interrupt() && local_softirq_pending())
 		invoke_softirq();
+
+#ifdef CONFIG_NO_HZ
+	/* Make sure that timer wheel updates are propagated */
+	if (!in_interrupt() && idle_cpu(smp_processor_id()) && !need_resched())
+		tick_nohz_stop_sched_tick();
+#endif
 	preempt_enable_no_resched();
 }
 
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index e0ac6cd79fc..3ca1d5ff031 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -90,12 +90,6 @@ extern char modprobe_path[];
 #ifdef CONFIG_CHR_DEV_SG
 extern int sg_big_buff;
 #endif
-#ifdef CONFIG_SYSVIPC
-static int proc_ipc_dointvec(ctl_table *table, int write, struct file *filp,
-		void __user *buffer, size_t *lenp, loff_t *ppos);
-static int proc_ipc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
-		void __user *buffer, size_t *lenp, loff_t *ppos);
-#endif
 
 #ifdef __sparc__
 extern char reboot_command [];
@@ -135,18 +129,6 @@ static int parse_table(int __user *, int, void __user *, size_t __user *,
 		void __user *, size_t, ctl_table *);
 #endif
 
-static int proc_do_uts_string(ctl_table *table, int write, struct file *filp,
-		  void __user *buffer, size_t *lenp, loff_t *ppos);
-
-static int sysctl_uts_string(ctl_table *table, int __user *name, int nlen,
-		  void __user *oldval, size_t __user *oldlenp,
-		  void __user *newval, size_t newlen);
-
-#ifdef CONFIG_SYSVIPC
-static int sysctl_ipc_data(ctl_table *table, int __user *name, int nlen,
-		  void __user *oldval, size_t __user *oldlenp,
-		  void __user *newval, size_t newlen);
-#endif
 
 #ifdef CONFIG_PROC_SYSCTL
 static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp,
@@ -177,60 +159,6 @@ int sysctl_legacy_va_layout;
 #endif
 
 
-static void *get_uts(ctl_table *table, int write)
-{
-	char *which = table->data;
-#ifdef CONFIG_UTS_NS
-	struct uts_namespace *uts_ns = current->nsproxy->uts_ns;
-	which = (which - (char *)&init_uts_ns) + (char *)uts_ns;
-#endif
-	if (!write)
-		down_read(&uts_sem);
-	else
-		down_write(&uts_sem);
-	return which;
-}
-
-static void put_uts(ctl_table *table, int write, void *which)
-{
-	if (!write)
-		up_read(&uts_sem);
-	else
-		up_write(&uts_sem);
-}
-
-#ifdef CONFIG_SYSVIPC
-static void *get_ipc(ctl_table *table, int write)
-{
-	char *which = table->data;
-	struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
-	which = (which - (char *)&init_ipc_ns) + (char *)ipc_ns;
-	return which;
-}
-#else
-#define get_ipc(T,W) ((T)->data)
-#endif
-
-/* /proc declarations: */
-
-#ifdef CONFIG_PROC_SYSCTL
-
-static ssize_t proc_readsys(struct file *, char __user *, size_t, loff_t *);
-static ssize_t proc_writesys(struct file *, const char __user *, size_t, loff_t *);
-static int proc_opensys(struct inode *, struct file *);
-
-const struct file_operations proc_sys_file_operations = {
-	.open		= proc_opensys,
-	.read		= proc_readsys,
-	.write		= proc_writesys,
-};
-
-extern struct proc_dir_entry *proc_sys_root;
-
-static void register_proc_table(ctl_table *, struct proc_dir_entry *, void *);
-static void unregister_proc_table(ctl_table *, struct proc_dir_entry *);
-#endif
-
 /* The default sysctl tables: */
 
 static ctl_table root_table[] = {
@@ -278,51 +206,6 @@ static ctl_table root_table[] = {
 
 static ctl_table kern_table[] = {
 	{
-		.ctl_name	= KERN_OSTYPE,
-		.procname	= "ostype",
-		.data		= init_uts_ns.name.sysname,
-		.maxlen		= sizeof(init_uts_ns.name.sysname),
-		.mode		= 0444,
-		.proc_handler	= &proc_do_uts_string,
-		.strategy	= &sysctl_uts_string,
-	},
-	{
-		.ctl_name	= KERN_OSRELEASE,
-		.procname	= "osrelease",
-		.data		= init_uts_ns.name.release,
-		.maxlen		= sizeof(init_uts_ns.name.release),
-		.mode		= 0444,
-		.proc_handler	= &proc_do_uts_string,
-		.strategy	= &sysctl_uts_string,
-	},
-	{
-		.ctl_name	= KERN_VERSION,
-		.procname	= "version",
-		.data		= init_uts_ns.name.version,
-		.maxlen		= sizeof(init_uts_ns.name.version),
-		.mode		= 0444,
-		.proc_handler	= &proc_do_uts_string,
-		.strategy	= &sysctl_uts_string,
-	},
-	{
-		.ctl_name	= KERN_NODENAME,
-		.procname	= "hostname",
-		.data		= init_uts_ns.name.nodename,
-		.maxlen		= sizeof(init_uts_ns.name.nodename),
-		.mode		= 0644,
-		.proc_handler	= &proc_do_uts_string,
-		.strategy	= &sysctl_uts_string,
-	},
-	{
-		.ctl_name	= KERN_DOMAINNAME,
-		.procname	= "domainname",
-		.data		= init_uts_ns.name.domainname,
-		.maxlen		= sizeof(init_uts_ns.name.domainname),
-		.mode		= 0644,
-		.proc_handler	= &proc_do_uts_string,
-		.strategy	= &sysctl_uts_string,
-	},
-	{
 		.ctl_name	= KERN_PANIC,
 		.procname	= "panic",
 		.data		= &panic_timeout,
@@ -478,71 +361,6 @@ static ctl_table kern_table[] = {
 		.proc_handler	= &proc_dointvec,
 	},
 #endif
-#ifdef CONFIG_SYSVIPC
-	{
-		.ctl_name	= KERN_SHMMAX,
-		.procname	= "shmmax",
-		.data		= &init_ipc_ns.shm_ctlmax,
-		.maxlen		= sizeof (init_ipc_ns.shm_ctlmax),
-		.mode		= 0644,
-		.proc_handler	= &proc_ipc_doulongvec_minmax,
-		.strategy	= sysctl_ipc_data,
-	},
-	{
-		.ctl_name	= KERN_SHMALL,
-		.procname	= "shmall",
-		.data		= &init_ipc_ns.shm_ctlall,
-		.maxlen		= sizeof (init_ipc_ns.shm_ctlall),
-		.mode		= 0644,
-		.proc_handler	= &proc_ipc_doulongvec_minmax,
-		.strategy	= sysctl_ipc_data,
-	},
-	{
-		.ctl_name	= KERN_SHMMNI,
-		.procname	= "shmmni",
-		.data		= &init_ipc_ns.shm_ctlmni,
-		.maxlen		= sizeof (init_ipc_ns.shm_ctlmni),
-		.mode		= 0644,
-		.proc_handler	= &proc_ipc_dointvec,
-		.strategy	= sysctl_ipc_data,
-	},
-	{
-		.ctl_name	= KERN_MSGMAX,
-		.procname	= "msgmax",
-		.data		= &init_ipc_ns.msg_ctlmax,
-		.maxlen		= sizeof (init_ipc_ns.msg_ctlmax),
-		.mode		= 0644,
-		.proc_handler	= &proc_ipc_dointvec,
-		.strategy	= sysctl_ipc_data,
-	},
-	{
-		.ctl_name	= KERN_MSGMNI,
-		.procname	= "msgmni",
-		.data		= &init_ipc_ns.msg_ctlmni,
-		.maxlen		= sizeof (init_ipc_ns.msg_ctlmni),
-		.mode		= 0644,
-		.proc_handler	= &proc_ipc_dointvec,
-		.strategy	= sysctl_ipc_data,
-	},
-	{
-		.ctl_name	= KERN_MSGMNB,
-		.procname	=  "msgmnb",
-		.data		= &init_ipc_ns.msg_ctlmnb,
-		.maxlen		= sizeof (init_ipc_ns.msg_ctlmnb),
-		.mode		= 0644,
-		.proc_handler	= &proc_ipc_dointvec,
-		.strategy	= sysctl_ipc_data,
-	},
-	{
-		.ctl_name	= KERN_SEM,
-		.procname	= "sem",
-		.data		= &init_ipc_ns.sem_ctls,
-		.maxlen		= 4*sizeof (int),
-		.mode		= 0644,
-		.proc_handler	= &proc_ipc_dointvec,
-		.strategy	= sysctl_ipc_data,
-	},
-#endif
 #ifdef CONFIG_MAGIC_SYSRQ
 	{
 		.ctl_name	= KERN_SYSRQ,
@@ -1043,6 +861,12 @@ static ctl_table vm_table[] = {
 	{ .ctl_name = 0 }
 };
 
+#if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
+static ctl_table binfmt_misc_table[] = {
+	{ .ctl_name = 0 }
+};
+#endif
+
 static ctl_table fs_table[] = {
 	{
 		.ctl_name	= FS_NRINODE,
@@ -1166,6 +990,14 @@ static ctl_table fs_table[] = {
 		.mode		= 0644,
 		.proc_handler	= &proc_dointvec,
 	},
+#if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
+	{
+		.ctl_name	= CTL_UNNUMBERED,
+		.procname	= "binfmt_misc",
+		.mode		= 0555,
+		.child		= binfmt_misc_table,
+	},
+#endif
 	{ .ctl_name = 0 }
 };
 
@@ -1177,8 +1009,6 @@ static ctl_table dev_table[] = {
 	{ .ctl_name = 0 }
 };
 
-extern void init_irq_proc (void);
-
 static DEFINE_SPINLOCK(sysctl_lock);
 
 /* called under sysctl_lock */
@@ -1220,19 +1050,47 @@ static void start_unregistering(struct ctl_table_header *p)
 	list_del_init(&p->ctl_entry);
 }
 
-void __init sysctl_init(void)
+void sysctl_head_finish(struct ctl_table_header *head)
 {
-#ifdef CONFIG_PROC_SYSCTL
-	register_proc_table(root_table, proc_sys_root, &root_table_header);
-	init_irq_proc();
-#endif
+	if (!head)
+		return;
+	spin_lock(&sysctl_lock);
+	unuse_table(head);
+	spin_unlock(&sysctl_lock);
+}
+
+struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
+{
+	struct ctl_table_header *head;
+	struct list_head *tmp;
+	spin_lock(&sysctl_lock);
+	if (prev) {
+		tmp = &prev->ctl_entry;
+		unuse_table(prev);
+		goto next;
+	}
+	tmp = &root_table_header.ctl_entry;
+	for (;;) {
+		head = list_entry(tmp, struct ctl_table_header, ctl_entry);
+
+		if (!use_table(head))
+			goto next;
+		spin_unlock(&sysctl_lock);
+		return head;
+	next:
+		tmp = tmp->next;
+		if (tmp == &root_table_header.ctl_entry)
+			break;
+	}
+	spin_unlock(&sysctl_lock);
+	return NULL;
 }
 
 #ifdef CONFIG_SYSCTL_SYSCALL
 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
 	       void __user *newval, size_t newlen)
 {
-	struct list_head *tmp;
+	struct ctl_table_header *head;
 	int error = -ENOTDIR;
 
 	if (nlen <= 0 || nlen >= CTL_MAXNAME)
@@ -1242,26 +1100,16 @@ int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *ol
 		if (!oldlenp || get_user(old_len, oldlenp))
 			return -EFAULT;
 	}
-	spin_lock(&sysctl_lock);
-	tmp = &root_table_header.ctl_entry;
-	do {
-		struct ctl_table_header *head =
-			list_entry(tmp, struct ctl_table_header, ctl_entry);
-
-		if (!use_table(head))
-			continue;
-
-		spin_unlock(&sysctl_lock);
 
+	for (head = sysctl_head_next(NULL); head;
+			head = sysctl_head_next(head)) {
 		error = parse_table(name, nlen, oldval, oldlenp, 
 					newval, newlen, head->ctl_table);
-
-		spin_lock(&sysctl_lock);
-		unuse_table(head);
-		if (error != -ENOTDIR)
+		if (error != -ENOTDIR) {
+			sysctl_head_finish(head);
 			break;
-	} while ((tmp = tmp->next) != &root_table_header.ctl_entry);
-	spin_unlock(&sysctl_lock);
+		}
+	}
 	return error;
 }
 
@@ -1282,7 +1130,7 @@ asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
 #endif /* CONFIG_SYSCTL_SYSCALL */
 
 /*
- * ctl_perm does NOT grant the superuser all rights automatically, because
+ * sysctl_perm does NOT grant the superuser all rights automatically, because
  * some sysctl variables are readonly even to root.
  */
 
@@ -1297,7 +1145,7 @@ static int test_perm(int mode, int op)
 	return -EACCES;
 }
 
-static inline int ctl_perm(ctl_table *table, int op)
+int sysctl_perm(ctl_table *table, int op)
 {
 	int error;
 	error = security_sysctl(table, op);
@@ -1321,19 +1169,11 @@ repeat:
 	for ( ; table->ctl_name || table->procname; table++) {
 		if (!table->ctl_name)
 			continue;
-		if (n == table->ctl_name || table->ctl_name == CTL_ANY) {
+		if (n == table->ctl_name) {
 			int error;
 			if (table->child) {
-				if (ctl_perm(table, 001))
+				if (sysctl_perm(table, 001))
 					return -EPERM;
-				if (table->strategy) {
-					error = table->strategy(
-						table, name, nlen,
-						oldval, oldlenp,
-						newval, newlen);
-					if (error)
-						return error;
-				}
 				name++;
 				nlen--;
 				table = table->child;
@@ -1361,7 +1201,7 @@ int do_sysctl_strategy (ctl_table *table,
 		op |= 004;
 	if (newval) 
 		op |= 002;
-	if (ctl_perm(table, op))
+	if (sysctl_perm(table, op))
 		return -EPERM;
 
 	if (table->strategy) {
@@ -1400,10 +1240,26 @@ int do_sysctl_strategy (ctl_table *table,
 }
 #endif /* CONFIG_SYSCTL_SYSCALL */
 
+static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
+{
+	for (; table->ctl_name || table->procname; table++) {
+		table->parent = parent;
+		if (table->child)
+			sysctl_set_parent(table, table->child);
+	}
+}
+
+static __init int sysctl_init(void)
+{
+	sysctl_set_parent(NULL, root_table);
+	return 0;
+}
+
+core_initcall(sysctl_init);
+
 /**
  * register_sysctl_table - register a sysctl hierarchy
  * @table: the top-level table structure
- * @insert_at_head: whether the entry should be inserted in front or at the end
  *
  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
  * array. An entry with a ctl_name of 0 terminates the table. 
@@ -1469,8 +1325,7 @@ int do_sysctl_strategy (ctl_table *table,
  * This routine returns %NULL on a failure to register, and a pointer
  * to the table header on success.
  */
-struct ctl_table_header *register_sysctl_table(ctl_table * table, 
-					       int insert_at_head)
+struct ctl_table_header *register_sysctl_table(ctl_table * table)
 {
 	struct ctl_table_header *tmp;
 	tmp = kmalloc(sizeof(struct ctl_table_header), GFP_KERNEL);
@@ -1480,15 +1335,10 @@ struct ctl_table_header *register_sysctl_table(ctl_table * table,
 	INIT_LIST_HEAD(&tmp->ctl_entry);
 	tmp->used = 0;
 	tmp->unregistering = NULL;
+	sysctl_set_parent(NULL, table);
 	spin_lock(&sysctl_lock);
-	if (insert_at_head)
-		list_add(&tmp->ctl_entry, &root_table_header.ctl_entry);
-	else
-		list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry);
+	list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry);
 	spin_unlock(&sysctl_lock);
-#ifdef CONFIG_PROC_SYSCTL
-	register_proc_table(table, proc_sys_root, tmp);
-#endif
 	return tmp;
 }
 
@@ -1504,9 +1354,6 @@ void unregister_sysctl_table(struct ctl_table_header * header)
 	might_sleep();
 	spin_lock(&sysctl_lock);
 	start_unregistering(header);
-#ifdef CONFIG_PROC_SYSCTL
-	unregister_proc_table(header->ctl_table, proc_sys_root);
-#endif
 	spin_unlock(&sysctl_lock);
 	kfree(header);
 }
@@ -1530,155 +1377,6 @@ void unregister_sysctl_table(struct ctl_table_header * table)
 
 #ifdef CONFIG_PROC_SYSCTL
 
-/* Scan the sysctl entries in table and add them all into /proc */
-static void register_proc_table(ctl_table * table, struct proc_dir_entry *root, void *set)
-{
-	struct proc_dir_entry *de;
-	int len;
-	mode_t mode;
-	
-	for (; table->ctl_name || table->procname; table++) {
-		/* Can't do anything without a proc name. */
-		if (!table->procname)
-			continue;
-		/* Maybe we can't do anything with it... */
-		if (!table->proc_handler && !table->child) {
-			printk(KERN_WARNING "SYSCTL: Can't register %s\n",
-				table->procname);
-			continue;
-		}
-
-		len = strlen(table->procname);
-		mode = table->mode;
-
-		de = NULL;
-		if (table->proc_handler)
-			mode |= S_IFREG;
-		else {
-			mode |= S_IFDIR;
-			for (de = root->subdir; de; de = de->next) {
-				if (proc_match(len, table->procname, de))
-					break;
-			}
-			/* If the subdir exists already, de is non-NULL */
-		}
-
-		if (!de) {
-			de = create_proc_entry(table->procname, mode, root);
-			if (!de)
-				continue;
-			de->set = set;
-			de->data = (void *) table;
-			if (table->proc_handler)
-				de->proc_fops = &proc_sys_file_operations;
-		}
-		table->de = de;
-		if (de->mode & S_IFDIR)
-			register_proc_table(table->child, de, set);
-	}
-}
-
-/*
- * Unregister a /proc sysctl table and any subdirectories.
- */
-static void unregister_proc_table(ctl_table * table, struct proc_dir_entry *root)
-{
-	struct proc_dir_entry *de;
-	for (; table->ctl_name || table->procname; table++) {
-		if (!(de = table->de))
-			continue;
-		if (de->mode & S_IFDIR) {
-			if (!table->child) {
-				printk (KERN_ALERT "Help - malformed sysctl tree on free\n");
-				continue;
-			}
-			unregister_proc_table(table->child, de);
-
-			/* Don't unregister directories which still have entries.. */
-			if (de->subdir)
-				continue;
-		}
-
-		/*
-		 * In any case, mark the entry as goner; we'll keep it
-		 * around if it's busy, but we'll know to do nothing with
-		 * its fields.  We are under sysctl_lock here.
-		 */
-		de->data = NULL;
-
-		/* Don't unregister proc entries that are still being used.. */
-		if (atomic_read(&de->count))
-			continue;
-
-		table->de = NULL;
-		remove_proc_entry(table->procname, root);
-	}
-}
-
-static ssize_t do_rw_proc(int write, struct file * file, char __user * buf,
-			  size_t count, loff_t *ppos)
-{
-	int op;
-	struct proc_dir_entry *de = PDE(file->f_path.dentry->d_inode);
-	struct ctl_table *table;
-	size_t res;
-	ssize_t error = -ENOTDIR;
-	
-	spin_lock(&sysctl_lock);
-	if (de && de->data && use_table(de->set)) {
-		/*
-		 * at that point we know that sysctl was not unregistered
-		 * and won't be until we finish
-		 */
-		spin_unlock(&sysctl_lock);
-		table = (struct ctl_table *) de->data;
-		if (!table || !table->proc_handler)
-			goto out;
-		error = -EPERM;
-		op = (write ? 002 : 004);
-		if (ctl_perm(table, op))
-			goto out;
-		
-		/* careful: calling conventions are nasty here */
-		res = count;
-		error = (*table->proc_handler)(table, write, file,
-						buf, &res, ppos);
-		if (!error)
-			error = res;
-	out:
-		spin_lock(&sysctl_lock);
-		unuse_table(de->set);
-	}
-	spin_unlock(&sysctl_lock);
-	return error;
-}
-
-static int proc_opensys(struct inode *inode, struct file *file)
-{
-	if (file->f_mode & FMODE_WRITE) {
-		/*
-		 * sysctl entries that are not writable,
-		 * are _NOT_ writable, capabilities or not.
-		 */
-		if (!(inode->i_mode & S_IWUSR))
-			return -EPERM;
-	}
-
-	return 0;
-}
-
-static ssize_t proc_readsys(struct file * file, char __user * buf,
-			    size_t count, loff_t *ppos)
-{
-	return do_rw_proc(0, file, buf, count, ppos);
-}
-
-static ssize_t proc_writesys(struct file * file, const char __user * buf,
-			     size_t count, loff_t *ppos)
-{
-	return do_rw_proc(1, file, (char __user *) buf, count, ppos);
-}
-
 static int _proc_do_string(void* data, int maxlen, int write,
 			   struct file *filp, void __user *buffer,
 			   size_t *lenp, loff_t *ppos)
@@ -1762,21 +1460,6 @@ int proc_dostring(ctl_table *table, int write, struct file *filp,
 			       buffer, lenp, ppos);
 }
 
-/*
- *	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,
-		  void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-	int r;
-	void *which;
-	which = get_uts(table, write);
-	r = _proc_do_string(which, table->maxlen,write,filp,buffer,lenp, ppos);
-	put_uts(table, write, which);
-	return r;
-}
 
 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
 				 int *valp,
@@ -2362,27 +2045,6 @@ int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
 				do_proc_dointvec_ms_jiffies_conv, NULL);
 }
 
-#ifdef CONFIG_SYSVIPC
-static int proc_ipc_dointvec(ctl_table *table, int write, struct file *filp,
-	void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-	void *which;
-	which = get_ipc(table, write);
-	return __do_proc_dointvec(which, table, write, filp, buffer,
-			lenp, ppos, NULL, NULL);
-}
-
-static int proc_ipc_doulongvec_minmax(ctl_table *table, int write,
-	struct file *filp, void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-	void *which;
-	which = get_ipc(table, write);
-	return __do_proc_doulongvec_minmax(which, table, write, filp, buffer,
-			lenp, ppos, 1l, 1l);
-}
-
-#endif
-
 static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp,
 			   void __user *buffer, size_t *lenp, loff_t *ppos)
 {
@@ -2413,31 +2075,6 @@ int proc_dostring(ctl_table *table, int write, struct file *filp,
 	return -ENOSYS;
 }
 
-static int proc_do_uts_string(ctl_table *table, int write, struct file *filp,
-		void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-	return -ENOSYS;
-}
-
-#ifdef CONFIG_SYSVIPC
-static int proc_do_ipc_string(ctl_table *table, int write, struct file *filp,
-		void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-	return -ENOSYS;
-}
-static int proc_ipc_dointvec(ctl_table *table, int write, struct file *filp,
-		void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-	return -ENOSYS;
-}
-static int proc_ipc_doulongvec_minmax(ctl_table *table, int write,
-		struct file *filp, void __user *buffer,
-		size_t *lenp, loff_t *ppos)
-{
-	return -ENOSYS;
-}
-#endif
-
 int proc_dointvec(ctl_table *table, int write, struct file *filp,
 		  void __user *buffer, size_t *lenp, loff_t *ppos)
 {
@@ -2648,62 +2285,6 @@ int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
 }
 
 
-/* The generic string strategy routine: */
-static int sysctl_uts_string(ctl_table *table, int __user *name, int nlen,
-		  void __user *oldval, size_t __user *oldlenp,
-		  void __user *newval, size_t newlen)
-{
-	struct ctl_table uts_table;
-	int r, write;
-	write = newval && newlen;
-	memcpy(&uts_table, table, sizeof(uts_table));
-	uts_table.data = get_uts(table, write);
-	r = sysctl_string(&uts_table, name, nlen,
-		oldval, oldlenp, newval, newlen);
-	put_uts(table, write, uts_table.data);
-	return r;
-}
-
-#ifdef CONFIG_SYSVIPC
-/* The generic sysctl ipc data routine. */
-static int sysctl_ipc_data(ctl_table *table, int __user *name, int nlen,
-		void __user *oldval, size_t __user *oldlenp,
-		void __user *newval, size_t newlen)
-{
-	size_t len;
-	void *data;
-
-	/* Get out of I don't have a variable */
-	if (!table->data || !table->maxlen)
-		return -ENOTDIR;
-
-	data = get_ipc(table, 1);
-	if (!data)
-		return -ENOTDIR;
-
-	if (oldval && oldlenp) {
-		if (get_user(len, oldlenp))
-			return -EFAULT;
-		if (len) {
-			if (len > table->maxlen)
-				len = table->maxlen;
-			if (copy_to_user(oldval, data, len))
-				return -EFAULT;
-			if (put_user(len, oldlenp))
-				return -EFAULT;
-		}
-	}
-
-	if (newval && newlen) {
-		if (newlen > table->maxlen)
-			newlen = table->maxlen;
-
-		if (copy_from_user(data, newval, newlen))
-			return -EFAULT;
-	}
-	return 1;
-}
-#endif
 
 #else /* CONFIG_SYSCTL_SYSCALL */
 
@@ -2769,20 +2350,6 @@ int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
 	return -ENOSYS;
 }
 
-static int sysctl_uts_string(ctl_table *table, int __user *name, int nlen,
-		  void __user *oldval, size_t __user *oldlenp,
-		  void __user *newval, size_t newlen)
-{
-	return -ENOSYS;
-}
-#ifdef CONFIG_SYSVIPC
-static int sysctl_ipc_data(ctl_table *table, int __user *name, int nlen,
-		void __user *oldval, size_t __user *oldlenp,
-		void __user *newval, size_t newlen)
-{
-	return -ENOSYS;
-}
-#endif
 #endif /* CONFIG_SYSCTL_SYSCALL */
 
 /*
diff --git a/kernel/time.c b/kernel/time.c
index 0e017bff4c1..c6c80ea5d0e 100644
--- a/kernel/time.c
+++ b/kernel/time.c
@@ -470,6 +470,260 @@ struct timeval ns_to_timeval(const s64 nsec)
 	return tv;
 }
 
+/*
+ * Convert jiffies to milliseconds and back.
+ *
+ * Avoid unnecessary multiplications/divisions in the
+ * two most common HZ cases:
+ */
+unsigned int jiffies_to_msecs(const unsigned long j)
+{
+#if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ)
+	return (MSEC_PER_SEC / HZ) * j;
+#elif HZ > MSEC_PER_SEC && !(HZ % MSEC_PER_SEC)
+	return (j + (HZ / MSEC_PER_SEC) - 1)/(HZ / MSEC_PER_SEC);
+#else
+	return (j * MSEC_PER_SEC) / HZ;
+#endif
+}
+EXPORT_SYMBOL(jiffies_to_msecs);
+
+unsigned int jiffies_to_usecs(const unsigned long j)
+{
+#if HZ <= USEC_PER_SEC && !(USEC_PER_SEC % HZ)
+	return (USEC_PER_SEC / HZ) * j;
+#elif HZ > USEC_PER_SEC && !(HZ % USEC_PER_SEC)
+	return (j + (HZ / USEC_PER_SEC) - 1)/(HZ / USEC_PER_SEC);
+#else
+	return (j * USEC_PER_SEC) / HZ;
+#endif
+}
+EXPORT_SYMBOL(jiffies_to_usecs);
+
+/*
+ * When we convert to jiffies then we interpret incoming values
+ * the following way:
+ *
+ * - negative values mean 'infinite timeout' (MAX_JIFFY_OFFSET)
+ *
+ * - 'too large' values [that would result in larger than
+ *   MAX_JIFFY_OFFSET values] mean 'infinite timeout' too.
+ *
+ * - all other values are converted to jiffies by either multiplying
+ *   the input value by a factor or dividing it with a factor
+ *
+ * We must also be careful about 32-bit overflows.
+ */
+unsigned long msecs_to_jiffies(const unsigned int m)
+{
+	/*
+	 * Negative value, means infinite timeout:
+	 */
+	if ((int)m < 0)
+		return MAX_JIFFY_OFFSET;
+
+#if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ)
+	/*
+	 * HZ is equal to or smaller than 1000, and 1000 is a nice
+	 * round multiple of HZ, divide with the factor between them,
+	 * but round upwards:
+	 */
+	return (m + (MSEC_PER_SEC / HZ) - 1) / (MSEC_PER_SEC / HZ);
+#elif HZ > MSEC_PER_SEC && !(HZ % MSEC_PER_SEC)
+	/*
+	 * HZ is larger than 1000, and HZ is a nice round multiple of
+	 * 1000 - simply multiply with the factor between them.
+	 *
+	 * But first make sure the multiplication result cannot
+	 * overflow:
+	 */
+	if (m > jiffies_to_msecs(MAX_JIFFY_OFFSET))
+		return MAX_JIFFY_OFFSET;
+
+	return m * (HZ / MSEC_PER_SEC);
+#else
+	/*
+	 * Generic case - multiply, round and divide. But first
+	 * check that if we are doing a net multiplication, that
+	 * we wouldnt overflow:
+	 */
+	if (HZ > MSEC_PER_SEC && m > jiffies_to_msecs(MAX_JIFFY_OFFSET))
+		return MAX_JIFFY_OFFSET;
+
+	return (m * HZ + MSEC_PER_SEC - 1) / MSEC_PER_SEC;
+#endif
+}
+EXPORT_SYMBOL(msecs_to_jiffies);
+
+unsigned long usecs_to_jiffies(const unsigned int u)
+{
+	if (u > jiffies_to_usecs(MAX_JIFFY_OFFSET))
+		return MAX_JIFFY_OFFSET;
+#if HZ <= USEC_PER_SEC && !(USEC_PER_SEC % HZ)
+	return (u + (USEC_PER_SEC / HZ) - 1) / (USEC_PER_SEC / HZ);
+#elif HZ > USEC_PER_SEC && !(HZ % USEC_PER_SEC)
+	return u * (HZ / USEC_PER_SEC);
+#else
+	return (u * HZ + USEC_PER_SEC - 1) / USEC_PER_SEC;
+#endif
+}
+EXPORT_SYMBOL(usecs_to_jiffies);
+
+/*
+ * The TICK_NSEC - 1 rounds up the value to the next resolution.  Note
+ * that a remainder subtract here would not do the right thing as the
+ * resolution values don't fall on second boundries.  I.e. the line:
+ * nsec -= nsec % TICK_NSEC; is NOT a correct resolution rounding.
+ *
+ * Rather, we just shift the bits off the right.
+ *
+ * The >> (NSEC_JIFFIE_SC - SEC_JIFFIE_SC) converts the scaled nsec
+ * value to a scaled second value.
+ */
+unsigned long
+timespec_to_jiffies(const struct timespec *value)
+{
+	unsigned long sec = value->tv_sec;
+	long nsec = value->tv_nsec + TICK_NSEC - 1;
+
+	if (sec >= MAX_SEC_IN_JIFFIES){
+		sec = MAX_SEC_IN_JIFFIES;
+		nsec = 0;
+	}
+	return (((u64)sec * SEC_CONVERSION) +
+		(((u64)nsec * NSEC_CONVERSION) >>
+		 (NSEC_JIFFIE_SC - SEC_JIFFIE_SC))) >> SEC_JIFFIE_SC;
+
+}
+EXPORT_SYMBOL(timespec_to_jiffies);
+
+void
+jiffies_to_timespec(const unsigned long jiffies, struct timespec *value)
+{
+	/*
+	 * Convert jiffies to nanoseconds and separate with
+	 * one divide.
+	 */
+	u64 nsec = (u64)jiffies * TICK_NSEC;
+	value->tv_sec = div_long_long_rem(nsec, NSEC_PER_SEC, &value->tv_nsec);
+}
+EXPORT_SYMBOL(jiffies_to_timespec);
+
+/* Same for "timeval"
+ *
+ * Well, almost.  The problem here is that the real system resolution is
+ * in nanoseconds and the value being converted is in micro seconds.
+ * Also for some machines (those that use HZ = 1024, in-particular),
+ * there is a LARGE error in the tick size in microseconds.
+
+ * The solution we use is to do the rounding AFTER we convert the
+ * microsecond part.  Thus the USEC_ROUND, the bits to be shifted off.
+ * Instruction wise, this should cost only an additional add with carry
+ * instruction above the way it was done above.
+ */
+unsigned long
+timeval_to_jiffies(const struct timeval *value)
+{
+	unsigned long sec = value->tv_sec;
+	long usec = value->tv_usec;
+
+	if (sec >= MAX_SEC_IN_JIFFIES){
+		sec = MAX_SEC_IN_JIFFIES;
+		usec = 0;
+	}
+	return (((u64)sec * SEC_CONVERSION) +
+		(((u64)usec * USEC_CONVERSION + USEC_ROUND) >>
+		 (USEC_JIFFIE_SC - SEC_JIFFIE_SC))) >> SEC_JIFFIE_SC;
+}
+
+void jiffies_to_timeval(const unsigned long jiffies, struct timeval *value)
+{
+	/*
+	 * Convert jiffies to nanoseconds and separate with
+	 * one divide.
+	 */
+	u64 nsec = (u64)jiffies * TICK_NSEC;
+	long tv_usec;
+
+	value->tv_sec = div_long_long_rem(nsec, NSEC_PER_SEC, &tv_usec);
+	tv_usec /= NSEC_PER_USEC;
+	value->tv_usec = tv_usec;
+}
+
+/*
+ * Convert jiffies/jiffies_64 to clock_t and back.
+ */
+clock_t jiffies_to_clock_t(long x)
+{
+#if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0
+	return x / (HZ / USER_HZ);
+#else
+	u64 tmp = (u64)x * TICK_NSEC;
+	do_div(tmp, (NSEC_PER_SEC / USER_HZ));
+	return (long)tmp;
+#endif
+}
+EXPORT_SYMBOL(jiffies_to_clock_t);
+
+unsigned long clock_t_to_jiffies(unsigned long x)
+{
+#if (HZ % USER_HZ)==0
+	if (x >= ~0UL / (HZ / USER_HZ))
+		return ~0UL;
+	return x * (HZ / USER_HZ);
+#else
+	u64 jif;
+
+	/* Don't worry about loss of precision here .. */
+	if (x >= ~0UL / HZ * USER_HZ)
+		return ~0UL;
+
+	/* .. but do try to contain it here */
+	jif = x * (u64) HZ;
+	do_div(jif, USER_HZ);
+	return jif;
+#endif
+}
+EXPORT_SYMBOL(clock_t_to_jiffies);
+
+u64 jiffies_64_to_clock_t(u64 x)
+{
+#if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0
+	do_div(x, HZ / USER_HZ);
+#else
+	/*
+	 * There are better ways that don't overflow early,
+	 * but even this doesn't overflow in hundreds of years
+	 * in 64 bits, so..
+	 */
+	x *= TICK_NSEC;
+	do_div(x, (NSEC_PER_SEC / USER_HZ));
+#endif
+	return x;
+}
+
+EXPORT_SYMBOL(jiffies_64_to_clock_t);
+
+u64 nsec_to_clock_t(u64 x)
+{
+#if (NSEC_PER_SEC % USER_HZ) == 0
+	do_div(x, (NSEC_PER_SEC / USER_HZ));
+#elif (USER_HZ % 512) == 0
+	x *= USER_HZ/512;
+	do_div(x, (NSEC_PER_SEC / 512));
+#else
+	/*
+         * max relative error 5.7e-8 (1.8s per year) for USER_HZ <= 1024,
+         * overflow after 64.99 years.
+         * exact for HZ=60, 72, 90, 120, 144, 180, 300, 600, 900, ...
+         */
+	x *= 9;
+	do_div(x, (unsigned long)((9ull * NSEC_PER_SEC + (USER_HZ/2)) /
+				  USER_HZ));
+#endif
+	return x;
+}
+
 #if (BITS_PER_LONG < 64)
 u64 get_jiffies_64(void)
 {
diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig
new file mode 100644
index 00000000000..f6635112654
--- /dev/null
+++ b/kernel/time/Kconfig
@@ -0,0 +1,25 @@
+#
+# Timer subsystem related configuration options
+#
+config TICK_ONESHOT
+	bool
+	default n
+
+config NO_HZ
+	bool "Tickless System (Dynamic Ticks)"
+	depends on GENERIC_TIME && GENERIC_CLOCKEVENTS
+	select TICK_ONESHOT
+	help
+	  This option enables a tickless system: timer interrupts will
+	  only trigger on an as-needed basis both when the system is
+	  busy and when the system is idle.
+
+config HIGH_RES_TIMERS
+	bool "High Resolution Timer Support"
+	depends on GENERIC_TIME && GENERIC_CLOCKEVENTS
+	select TICK_ONESHOT
+	help
+	  This option enables high resolution timer support. If your
+	  hardware is not capable then this option only increases
+	  the size of the kernel image.
+
diff --git a/kernel/time/Makefile b/kernel/time/Makefile
index 61a3907d16f..93bccba1f26 100644
--- a/kernel/time/Makefile
+++ b/kernel/time/Makefile
@@ -1 +1,8 @@
-obj-y += ntp.o clocksource.o jiffies.o
+obj-y += ntp.o clocksource.o jiffies.o timer_list.o
+
+obj-$(CONFIG_GENERIC_CLOCKEVENTS)		+= clockevents.o
+obj-$(CONFIG_GENERIC_CLOCKEVENTS)		+= tick-common.o
+obj-$(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST)	+= tick-broadcast.o
+obj-$(CONFIG_TICK_ONESHOT)			+= tick-oneshot.o
+obj-$(CONFIG_TICK_ONESHOT)			+= tick-sched.o
+obj-$(CONFIG_TIMER_STATS)			+= timer_stats.o
diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
new file mode 100644
index 00000000000..67932ea78c1
--- /dev/null
+++ b/kernel/time/clockevents.c
@@ -0,0 +1,345 @@
+/*
+ * linux/kernel/time/clockevents.c
+ *
+ * This file contains functions which manage clock event devices.
+ *
+ * Copyright(C) 2005-2006, Thomas Gleixner <tglx@linutronix.de>
+ * Copyright(C) 2005-2007, Red Hat, Inc., Ingo Molnar
+ * Copyright(C) 2006-2007, Timesys Corp., Thomas Gleixner
+ *
+ * This code is licenced under the GPL version 2. For details see
+ * kernel-base/COPYING.
+ */
+
+#include <linux/clockchips.h>
+#include <linux/hrtimer.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/smp.h>
+#include <linux/sysdev.h>
+
+/* The registered clock event devices */
+static LIST_HEAD(clockevent_devices);
+static LIST_HEAD(clockevents_released);
+
+/* Notification for clock events */
+static RAW_NOTIFIER_HEAD(clockevents_chain);
+
+/* Protection for the above */
+static DEFINE_SPINLOCK(clockevents_lock);
+
+/**
+ * clockevents_delta2ns - Convert a latch value (device ticks) to nanoseconds
+ * @latch:	value to convert
+ * @evt:	pointer to clock event device descriptor
+ *
+ * Math helper, returns latch value converted to nanoseconds (bound checked)
+ */
+unsigned long clockevent_delta2ns(unsigned long latch,
+				  struct clock_event_device *evt)
+{
+	u64 clc = ((u64) latch << evt->shift);
+
+	do_div(clc, evt->mult);
+	if (clc < 1000)
+		clc = 1000;
+	if (clc > LONG_MAX)
+		clc = LONG_MAX;
+
+	return (unsigned long) clc;
+}
+
+/**
+ * clockevents_set_mode - set the operating mode of a clock event device
+ * @dev:	device to modify
+ * @mode:	new mode
+ *
+ * Must be called with interrupts disabled !
+ */
+void clockevents_set_mode(struct clock_event_device *dev,
+				 enum clock_event_mode mode)
+{
+	if (dev->mode != mode) {
+		dev->set_mode(mode, dev);
+		dev->mode = mode;
+	}
+}
+
+/**
+ * clockevents_program_event - Reprogram the clock event device.
+ * @expires:	absolute expiry time (monotonic clock)
+ *
+ * Returns 0 on success, -ETIME when the event is in the past.
+ */
+int clockevents_program_event(struct clock_event_device *dev, ktime_t expires,
+			      ktime_t now)
+{
+	unsigned long long clc;
+	int64_t delta;
+
+	delta = ktime_to_ns(ktime_sub(expires, now));
+
+	if (delta <= 0)
+		return -ETIME;
+
+	dev->next_event = expires;
+
+	if (dev->mode == CLOCK_EVT_MODE_SHUTDOWN)
+		return 0;
+
+	if (delta > dev->max_delta_ns)
+		delta = dev->max_delta_ns;
+	if (delta < dev->min_delta_ns)
+		delta = dev->min_delta_ns;
+
+	clc = delta * dev->mult;
+	clc >>= dev->shift;
+
+	return dev->set_next_event((unsigned long) clc, dev);
+}
+
+/**
+ * clockevents_register_notifier - register a clock events change listener
+ */
+int clockevents_register_notifier(struct notifier_block *nb)
+{
+	int ret;
+
+	spin_lock(&clockevents_lock);
+	ret = raw_notifier_chain_register(&clockevents_chain, nb);
+	spin_unlock(&clockevents_lock);
+
+	return ret;
+}
+
+/**
+ * clockevents_unregister_notifier - unregister a clock events change listener
+ */
+void clockevents_unregister_notifier(struct notifier_block *nb)
+{
+	spin_lock(&clockevents_lock);
+	raw_notifier_chain_unregister(&clockevents_chain, nb);
+	spin_unlock(&clockevents_lock);
+}
+
+/*
+ * Notify about a clock event change. Called with clockevents_lock
+ * held.
+ */
+static void clockevents_do_notify(unsigned long reason, void *dev)
+{
+	raw_notifier_call_chain(&clockevents_chain, reason, dev);
+}
+
+/*
+ * Called after a notify add to make devices availble which were
+ * released from the notifier call.
+ */
+static void clockevents_notify_released(void)
+{
+	struct clock_event_device *dev;
+
+	while (!list_empty(&clockevents_released)) {
+		dev = list_entry(clockevents_released.next,
+				 struct clock_event_device, list);
+		list_del(&dev->list);
+		list_add(&dev->list, &clockevent_devices);
+		clockevents_do_notify(CLOCK_EVT_NOTIFY_ADD, dev);
+	}
+}
+
+/**
+ * clockevents_register_device - register a clock event device
+ * @dev:	device to register
+ */
+void clockevents_register_device(struct clock_event_device *dev)
+{
+	BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED);
+
+	spin_lock(&clockevents_lock);
+
+	list_add(&dev->list, &clockevent_devices);
+	clockevents_do_notify(CLOCK_EVT_NOTIFY_ADD, dev);
+	clockevents_notify_released();
+
+	spin_unlock(&clockevents_lock);
+}
+
+/*
+ * Noop handler when we shut down an event device
+ */
+static void clockevents_handle_noop(struct clock_event_device *dev)
+{
+}
+
+/**
+ * clockevents_exchange_device - release and request clock devices
+ * @old:	device to release (can be NULL)
+ * @new:	device to request (can be NULL)
+ *
+ * Called from the notifier chain. clockevents_lock is held already
+ */
+void clockevents_exchange_device(struct clock_event_device *old,
+				 struct clock_event_device *new)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	/*
+	 * Caller releases a clock event device. We queue it into the
+	 * released list and do a notify add later.
+	 */
+	if (old) {
+		old->event_handler = clockevents_handle_noop;
+		clockevents_set_mode(old, CLOCK_EVT_MODE_UNUSED);
+		list_del(&old->list);
+		list_add(&old->list, &clockevents_released);
+	}
+
+	if (new) {
+		BUG_ON(new->mode != CLOCK_EVT_MODE_UNUSED);
+		clockevents_set_mode(new, CLOCK_EVT_MODE_SHUTDOWN);
+	}
+	local_irq_restore(flags);
+}
+
+/**
+ * clockevents_request_device
+ */
+struct clock_event_device *clockevents_request_device(unsigned int features,
+						      cpumask_t cpumask)
+{
+	struct clock_event_device *cur, *dev = NULL;
+	struct list_head *tmp;
+
+	spin_lock(&clockevents_lock);
+
+	list_for_each(tmp, &clockevent_devices) {
+		cur = list_entry(tmp, struct clock_event_device, list);
+
+		if ((cur->features & features) == features &&
+		    cpus_equal(cpumask, cur->cpumask)) {
+			if (!dev || dev->rating < cur->rating)
+				dev = cur;
+		}
+	}
+
+	clockevents_exchange_device(NULL, dev);
+
+	spin_unlock(&clockevents_lock);
+
+	return dev;
+}
+
+/**
+ * clockevents_release_device
+ */
+void clockevents_release_device(struct clock_event_device *dev)
+{
+	spin_lock(&clockevents_lock);
+
+	clockevents_exchange_device(dev, NULL);
+	clockevents_notify_released();
+
+	spin_unlock(&clockevents_lock);
+}
+
+/**
+ * clockevents_notify - notification about relevant events
+ */
+void clockevents_notify(unsigned long reason, void *arg)
+{
+	spin_lock(&clockevents_lock);
+	clockevents_do_notify(reason, arg);
+
+	switch (reason) {
+	case CLOCK_EVT_NOTIFY_CPU_DEAD:
+		/*
+		 * Unregister the clock event devices which were
+		 * released from the users in the notify chain.
+		 */
+		while (!list_empty(&clockevents_released)) {
+			struct clock_event_device *dev;
+
+			dev = list_entry(clockevents_released.next,
+					 struct clock_event_device, list);
+			list_del(&dev->list);
+		}
+		break;
+	default:
+		break;
+	}
+	spin_unlock(&clockevents_lock);
+}
+EXPORT_SYMBOL_GPL(clockevents_notify);
+
+#ifdef CONFIG_SYSFS
+
+/**
+ * clockevents_show_registered - sysfs interface for listing clockevents
+ * @dev:	unused
+ * @buf:	char buffer to be filled with clock events list
+ *
+ * Provides sysfs interface for listing registered clock event devices
+ */
+static ssize_t clockevents_show_registered(struct sys_device *dev, char *buf)
+{
+	struct list_head *tmp;
+	char *p = buf;
+	int cpu;
+
+	spin_lock(&clockevents_lock);
+
+	list_for_each(tmp, &clockevent_devices) {
+		struct clock_event_device *ce;
+
+		ce = list_entry(tmp, struct clock_event_device, list);
+		p += sprintf(p, "%-20s F:%04x M:%d", ce->name,
+			     ce->features, ce->mode);
+		p += sprintf(p, " C:");
+		if (!cpus_equal(ce->cpumask, cpu_possible_map)) {
+			for_each_cpu_mask(cpu, ce->cpumask)
+				p += sprintf(p, " %d", cpu);
+		} else {
+			/*
+			 * FIXME: Add the cpu which is handling this sucker
+			 */
+		}
+		p += sprintf(p, "\n");
+	}
+
+	spin_unlock(&clockevents_lock);
+
+	return p - buf;
+}
+
+/*
+ * Sysfs setup bits:
+ */
+static SYSDEV_ATTR(registered, 0600,
+		   clockevents_show_registered, NULL);
+
+static struct sysdev_class clockevents_sysclass = {
+	set_kset_name("clockevents"),
+};
+
+static struct sys_device clockevents_sys_device = {
+	.id	= 0,
+	.cls	= &clockevents_sysclass,
+};
+
+static int __init clockevents_sysfs_init(void)
+{
+	int error = sysdev_class_register(&clockevents_sysclass);
+
+	if (!error)
+		error = sysdev_register(&clockevents_sys_device);
+	if (!error)
+		error = sysdev_create_file(
+				&clockevents_sys_device,
+				&attr_registered);
+	return error;
+}
+device_initcall(clockevents_sysfs_init);
+#endif
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index d9ef176c4e0..193a0793af9 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -29,6 +29,7 @@
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/sched.h> /* for spin_unlock_irq() using preempt_count() m68k */
+#include <linux/tick.h>
 
 /* XXX - Would like a better way for initializing curr_clocksource */
 extern struct clocksource clocksource_jiffies;
@@ -48,6 +49,7 @@ extern struct clocksource clocksource_jiffies;
  */
 static struct clocksource *curr_clocksource = &clocksource_jiffies;
 static struct clocksource *next_clocksource;
+static struct clocksource *clocksource_override;
 static LIST_HEAD(clocksource_list);
 static DEFINE_SPINLOCK(clocksource_lock);
 static char override_name[32];
@@ -62,9 +64,123 @@ static int __init clocksource_done_booting(void)
 	finished_booting = 1;
 	return 0;
 }
-
 late_initcall(clocksource_done_booting);
 
+#ifdef CONFIG_CLOCKSOURCE_WATCHDOG
+static LIST_HEAD(watchdog_list);
+static struct clocksource *watchdog;
+static struct timer_list watchdog_timer;
+static DEFINE_SPINLOCK(watchdog_lock);
+static cycle_t watchdog_last;
+/*
+ * Interval: 0.5sec Treshold: 0.0625s
+ */
+#define WATCHDOG_INTERVAL (HZ >> 1)
+#define WATCHDOG_TRESHOLD (NSEC_PER_SEC >> 4)
+
+static void clocksource_ratewd(struct clocksource *cs, int64_t delta)
+{
+	if (delta > -WATCHDOG_TRESHOLD && delta < WATCHDOG_TRESHOLD)
+		return;
+
+	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);
+	cs->flags &= ~CLOCK_SOURCE_WATCHDOG;
+	list_del(&cs->wd_list);
+}
+
+static void clocksource_watchdog(unsigned long data)
+{
+	struct clocksource *cs, *tmp;
+	cycle_t csnow, wdnow;
+	int64_t wd_nsec, cs_nsec;
+
+	spin_lock(&watchdog_lock);
+
+	wdnow = watchdog->read();
+	wd_nsec = cyc2ns(watchdog, (wdnow - watchdog_last) & watchdog->mask);
+	watchdog_last = wdnow;
+
+	list_for_each_entry_safe(cs, tmp, &watchdog_list, wd_list) {
+		csnow = cs->read();
+		/* 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);
+		}
+	}
+
+	if (!list_empty(&watchdog_list)) {
+		__mod_timer(&watchdog_timer,
+			    watchdog_timer.expires + WATCHDOG_INTERVAL);
+	}
+	spin_unlock(&watchdog_lock);
+}
+static void clocksource_check_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);
+
+		list_add(&cs->wd_list, &watchdog_list);
+		if (!started && watchdog) {
+			watchdog_last = watchdog->read();
+			watchdog_timer.expires = jiffies + WATCHDOG_INTERVAL;
+			add_timer(&watchdog_timer);
+		}
+	} else if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS) {
+			cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES;
+
+		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_timer.expires =
+					jiffies + WATCHDOG_INTERVAL;
+				add_timer(&watchdog_timer);
+			}
+		}
+	}
+	spin_unlock_irqrestore(&watchdog_lock, flags);
+}
+#else
+static void clocksource_check_watchdog(struct clocksource *cs)
+{
+	if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS)
+		cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES;
+}
+#endif
+
 /**
  * clocksource_get_next - Returns the selected clocksource
  *
@@ -84,60 +200,54 @@ struct clocksource *clocksource_get_next(void)
 }
 
 /**
- * select_clocksource - Finds the best registered clocksource.
+ * select_clocksource - Selects the best registered clocksource.
  *
  * Private function. Must hold clocksource_lock when called.
  *
- * Looks through the list of registered clocksources, returning
- * the one with the highest rating value. If there is a clocksource
- * name that matches the override string, it returns that clocksource.
+ * Select the clocksource with the best rating, or the clocksource,
+ * which is selected by userspace override.
  */
 static struct clocksource *select_clocksource(void)
 {
-	struct clocksource *best = NULL;
-	struct list_head *tmp;
+	struct clocksource *next;
 
-	list_for_each(tmp, &clocksource_list) {
-		struct clocksource *src;
+	if (list_empty(&clocksource_list))
+		return NULL;
 
-		src = list_entry(tmp, struct clocksource, list);
-		if (!best)
-			best = src;
-
-		/* check for override: */
-		if (strlen(src->name) == strlen(override_name) &&
-		    !strcmp(src->name, override_name)) {
-			best = src;
-			break;
-		}
-		/* pick the highest rating: */
-		if (src->rating > best->rating)
-		 	best = src;
-	}
+	if (clocksource_override)
+		next = clocksource_override;
+	else
+		next = list_entry(clocksource_list.next, struct clocksource,
+				  list);
+
+	if (next == curr_clocksource)
+		return NULL;
 
-	return best;
+	return next;
 }
 
-/**
- * is_registered_source - Checks if clocksource is registered
- * @c:		pointer to a clocksource
- *
- * Private helper function. Must hold clocksource_lock when called.
- *
- * Returns one if the clocksource is already registered, zero otherwise.
+/*
+ * Enqueue the clocksource sorted by rating
  */
-static int is_registered_source(struct clocksource *c)
+static int clocksource_enqueue(struct clocksource *c)
 {
-	int len = strlen(c->name);
-	struct list_head *tmp;
+	struct list_head *tmp, *entry = &clocksource_list;
 
 	list_for_each(tmp, &clocksource_list) {
-		struct clocksource *src;
-
-		src = list_entry(tmp, struct clocksource, list);
-		if (strlen(src->name) == len &&	!strcmp(src->name, c->name))
-			return 1;
+		struct clocksource *cs;
+
+		cs = list_entry(tmp, struct clocksource, list);
+		if (cs == c)
+			return -EBUSY;
+		/* 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;
 }
@@ -150,42 +260,35 @@ static int is_registered_source(struct clocksource *c)
  */
 int clocksource_register(struct clocksource *c)
 {
-	int ret = 0;
 	unsigned long flags;
+	int ret;
 
 	spin_lock_irqsave(&clocksource_lock, flags);
-	/* check if clocksource is already registered */
-	if (is_registered_source(c)) {
-		printk("register_clocksource: Cannot register %s. "
-		       "Already registered!", c->name);
-		ret = -EBUSY;
-	} else {
-		/* register it */
- 		list_add(&c->list, &clocksource_list);
-		/* scan the registered clocksources, and pick the best one */
+	ret = clocksource_enqueue(c);
+	if (!ret)
 		next_clocksource = select_clocksource();
-	}
 	spin_unlock_irqrestore(&clocksource_lock, flags);
+	if (!ret)
+		clocksource_check_watchdog(c);
 	return ret;
 }
 EXPORT_SYMBOL(clocksource_register);
 
 /**
- * clocksource_reselect - Rescan list for next clocksource
+ * clocksource_change_rating - Change the rating of a registered clocksource
  *
- * A quick helper function to be used if a clocksource changes its
- * rating. Forces the clocksource list to be re-scanned for the best
- * clocksource.
  */
-void clocksource_reselect(void)
+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);
 }
-EXPORT_SYMBOL(clocksource_reselect);
 
 #ifdef CONFIG_SYSFS
 /**
@@ -221,7 +324,11 @@ sysfs_show_current_clocksources(struct sys_device *dev, char *buf)
 static ssize_t sysfs_override_clocksource(struct sys_device *dev,
 					  const char *buf, size_t count)
 {
+	struct clocksource *ovr = NULL;
+	struct list_head *tmp;
 	size_t ret = count;
+	int len;
+
 	/* strings from sysfs write are not 0 terminated! */
 	if (count >= sizeof(override_name))
 		return -EINVAL;
@@ -229,17 +336,32 @@ static ssize_t sysfs_override_clocksource(struct sys_device *dev,
 	/* strip of \n: */
 	if (buf[count-1] == '\n')
 		count--;
-	if (count < 1)
-		return -EINVAL;
 
 	spin_lock_irq(&clocksource_lock);
 
-	/* copy the name given: */
-	memcpy(override_name, buf, count);
+	if (count > 0)
+		memcpy(override_name, buf, count);
 	override_name[count] = 0;
 
-	/* try to select it: */
-	next_clocksource = select_clocksource();
+	len = strlen(override_name);
+	if (len) {
+		ovr = clocksource_override;
+		/* try to select it: */
+		list_for_each(tmp, &clocksource_list) {
+			struct clocksource *cs;
+
+			cs = list_entry(tmp, struct clocksource, list);
+			if (strlen(cs->name) == len &&
+			    !strcmp(cs->name, override_name))
+				ovr = cs;
+		}
+	}
+
+	/* Reselect, when the override name has changed */
+	if (ovr != clocksource_override) {
+		clocksource_override = ovr;
+		next_clocksource = select_clocksource();
+	}
 
 	spin_unlock_irq(&clocksource_lock);
 
diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c
index a99b2a6e6a0..3be8da8fed7 100644
--- a/kernel/time/jiffies.c
+++ b/kernel/time/jiffies.c
@@ -62,7 +62,6 @@ struct clocksource clocksource_jiffies = {
 	.mask		= 0xffffffff, /*32bits*/
 	.mult		= NSEC_PER_JIFFY << JIFFIES_SHIFT, /* details above */
 	.shift		= JIFFIES_SHIFT,
-	.is_continuous	= 0, /* tick based, not free running */
 };
 
 static int __init init_jiffies_clocksource(void)
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index 3afeaa3a73f..eb12509e00b 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -24,7 +24,7 @@ static u64 tick_length, tick_length_base;
 
 #define MAX_TICKADJ		500		/* microsecs */
 #define MAX_TICKADJ_SCALED	(((u64)(MAX_TICKADJ * NSEC_PER_USEC) << \
-				  TICK_LENGTH_SHIFT) / HZ)
+				  TICK_LENGTH_SHIFT) / NTP_INTERVAL_FREQ)
 
 /*
  * phase-lock loop variables
@@ -46,13 +46,17 @@ long time_adjust;
 
 static void ntp_update_frequency(void)
 {
-	tick_length_base = (u64)(tick_usec * NSEC_PER_USEC * USER_HZ) << TICK_LENGTH_SHIFT;
-	tick_length_base += (s64)CLOCK_TICK_ADJUST << TICK_LENGTH_SHIFT;
-	tick_length_base += (s64)time_freq << (TICK_LENGTH_SHIFT - SHIFT_NSEC);
+	u64 second_length = (u64)(tick_usec * NSEC_PER_USEC * USER_HZ)
+				<< TICK_LENGTH_SHIFT;
+	second_length += (s64)CLOCK_TICK_ADJUST << TICK_LENGTH_SHIFT;
+	second_length += (s64)time_freq << (TICK_LENGTH_SHIFT - SHIFT_NSEC);
 
-	do_div(tick_length_base, HZ);
+	tick_length_base = second_length;
 
-	tick_nsec = tick_length_base >> TICK_LENGTH_SHIFT;
+	do_div(second_length, HZ);
+	tick_nsec = second_length >> TICK_LENGTH_SHIFT;
+
+	do_div(tick_length_base, NTP_INTERVAL_FREQ);
 }
 
 /**
@@ -162,7 +166,7 @@ void second_overflow(void)
 			tick_length -= MAX_TICKADJ_SCALED;
 		} else {
 			tick_length += (s64)(time_adjust * NSEC_PER_USEC /
-					     HZ) << TICK_LENGTH_SHIFT;
+					NTP_INTERVAL_FREQ) << TICK_LENGTH_SHIFT;
 			time_adjust = 0;
 		}
 	}
@@ -239,7 +243,8 @@ int do_adjtimex(struct timex *txc)
 		    result = -EINVAL;
 		    goto leave;
 		}
-		time_freq = ((s64)txc->freq * NSEC_PER_USEC) >> (SHIFT_USEC - SHIFT_NSEC);
+		time_freq = ((s64)txc->freq * NSEC_PER_USEC)
+				>> (SHIFT_USEC - SHIFT_NSEC);
 	    }
 
 	    if (txc->modes & ADJ_MAXERROR) {
@@ -309,7 +314,8 @@ int do_adjtimex(struct timex *txc)
 		    freq_adj += time_freq;
 		    freq_adj = min(freq_adj, (s64)MAXFREQ_NSEC);
 		    time_freq = max(freq_adj, (s64)-MAXFREQ_NSEC);
-		    time_offset = (time_offset / HZ) << SHIFT_UPDATE;
+		    time_offset = (time_offset / NTP_INTERVAL_FREQ)
+		    			<< SHIFT_UPDATE;
 		} /* STA_PLL */
 	    } /* txc->modes & ADJ_OFFSET */
 	    if (txc->modes & ADJ_TICK)
@@ -324,8 +330,10 @@ leave:	if ((time_status & (STA_UNSYNC|STA_CLOCKERR)) != 0)
 	if ((txc->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT)
 	    txc->offset	   = save_adjust;
 	else
-	    txc->offset    = shift_right(time_offset, SHIFT_UPDATE) * HZ / 1000;
-	txc->freq	   = (time_freq / NSEC_PER_USEC) << (SHIFT_USEC - SHIFT_NSEC);
+	    txc->offset    = shift_right(time_offset, SHIFT_UPDATE)
+	    			* NTP_INTERVAL_FREQ / 1000;
+	txc->freq	   = (time_freq / NSEC_PER_USEC)
+				<< (SHIFT_USEC - SHIFT_NSEC);
 	txc->maxerror	   = time_maxerror;
 	txc->esterror	   = time_esterror;
 	txc->status	   = time_status;
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
new file mode 100644
index 00000000000..12b3efeb9f6
--- /dev/null
+++ b/kernel/time/tick-broadcast.c
@@ -0,0 +1,480 @@
+/*
+ * linux/kernel/time/tick-broadcast.c
+ *
+ * This file contains functions which emulate a local clock-event
+ * device via a broadcast event source.
+ *
+ * Copyright(C) 2005-2006, Thomas Gleixner <tglx@linutronix.de>
+ * Copyright(C) 2005-2007, Red Hat, Inc., Ingo Molnar
+ * Copyright(C) 2006-2007, Timesys Corp., Thomas Gleixner
+ *
+ * This code is licenced under the GPL version 2. For details see
+ * kernel-base/COPYING.
+ */
+#include <linux/cpu.h>
+#include <linux/err.h>
+#include <linux/hrtimer.h>
+#include <linux/irq.h>
+#include <linux/percpu.h>
+#include <linux/profile.h>
+#include <linux/sched.h>
+#include <linux/tick.h>
+
+#include "tick-internal.h"
+
+/*
+ * Broadcast support for broken x86 hardware, where the local apic
+ * timer stops in C3 state.
+ */
+
+struct tick_device tick_broadcast_device;
+static cpumask_t tick_broadcast_mask;
+static DEFINE_SPINLOCK(tick_broadcast_lock);
+
+/*
+ * Debugging: see timer_list.c
+ */
+struct tick_device *tick_get_broadcast_device(void)
+{
+	return &tick_broadcast_device;
+}
+
+cpumask_t *tick_get_broadcast_mask(void)
+{
+	return &tick_broadcast_mask;
+}
+
+/*
+ * Start the device in periodic mode
+ */
+static void tick_broadcast_start_periodic(struct clock_event_device *bc)
+{
+	if (bc && bc->mode == CLOCK_EVT_MODE_SHUTDOWN)
+		tick_setup_periodic(bc, 1);
+}
+
+/*
+ * Check, if the device can be utilized as broadcast device:
+ */
+int tick_check_broadcast_device(struct clock_event_device *dev)
+{
+	if (tick_broadcast_device.evtdev ||
+	    (dev->features & CLOCK_EVT_FEAT_C3STOP))
+		return 0;
+
+	clockevents_exchange_device(NULL, dev);
+	tick_broadcast_device.evtdev = dev;
+	if (!cpus_empty(tick_broadcast_mask))
+		tick_broadcast_start_periodic(dev);
+	return 1;
+}
+
+/*
+ * Check, if the device is the broadcast device
+ */
+int tick_is_broadcast_device(struct clock_event_device *dev)
+{
+	return (dev && tick_broadcast_device.evtdev == dev);
+}
+
+/*
+ * Check, if the device is disfunctional and a place holder, which
+ * needs to be handled by the broadcast device.
+ */
+int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu)
+{
+	unsigned long flags;
+	int ret = 0;
+
+	spin_lock_irqsave(&tick_broadcast_lock, flags);
+
+	/*
+	 * Devices might be registered with both periodic and oneshot
+	 * mode disabled. This signals, that the device needs to be
+	 * operated from the broadcast device and is a placeholder for
+	 * the cpu local device.
+	 */
+	if (!tick_device_is_functional(dev)) {
+		dev->event_handler = tick_handle_periodic;
+		cpu_set(cpu, tick_broadcast_mask);
+		tick_broadcast_start_periodic(tick_broadcast_device.evtdev);
+		ret = 1;
+	}
+
+	spin_unlock_irqrestore(&tick_broadcast_lock, flags);
+	return ret;
+}
+
+/*
+ * Broadcast the event to the cpus, which are set in the mask
+ */
+int tick_do_broadcast(cpumask_t mask)
+{
+	int ret = 0, cpu = smp_processor_id();
+	struct tick_device *td;
+
+	/*
+	 * Check, if the current cpu is in the mask
+	 */
+	if (cpu_isset(cpu, mask)) {
+		cpu_clear(cpu, mask);
+		td = &per_cpu(tick_cpu_device, cpu);
+		td->evtdev->event_handler(td->evtdev);
+		ret = 1;
+	}
+
+	if (!cpus_empty(mask)) {
+		/*
+		 * It might be necessary to actually check whether the devices
+		 * have different broadcast functions. For now, just use the
+		 * one of the first device. This works as long as we have this
+		 * misfeature only on x86 (lapic)
+		 */
+		cpu = first_cpu(mask);
+		td = &per_cpu(tick_cpu_device, cpu);
+		td->evtdev->broadcast(mask);
+		ret = 1;
+	}
+	return ret;
+}
+
+/*
+ * Periodic broadcast:
+ * - invoke the broadcast handlers
+ */
+static void tick_do_periodic_broadcast(void)
+{
+	cpumask_t mask;
+
+	spin_lock(&tick_broadcast_lock);
+
+	cpus_and(mask, cpu_online_map, tick_broadcast_mask);
+	tick_do_broadcast(mask);
+
+	spin_unlock(&tick_broadcast_lock);
+}
+
+/*
+ * Event handler for periodic broadcast ticks
+ */
+static void tick_handle_periodic_broadcast(struct clock_event_device *dev)
+{
+	dev->next_event.tv64 = KTIME_MAX;
+
+	tick_do_periodic_broadcast();
+
+	/*
+	 * The device is in periodic mode. No reprogramming necessary:
+	 */
+	if (dev->mode == CLOCK_EVT_MODE_PERIODIC)
+		return;
+
+	/*
+	 * Setup the next period for devices, which do not have
+	 * periodic mode:
+	 */
+	for (;;) {
+		ktime_t next = ktime_add(dev->next_event, tick_period);
+
+		if (!clockevents_program_event(dev, next, ktime_get()))
+			return;
+		tick_do_periodic_broadcast();
+	}
+}
+
+/*
+ * Powerstate information: The system enters/leaves a state, where
+ * affected devices might stop
+ */
+static void tick_do_broadcast_on_off(void *why)
+{
+	struct clock_event_device *bc, *dev;
+	struct tick_device *td;
+	unsigned long flags, *reason = why;
+	int cpu;
+
+	spin_lock_irqsave(&tick_broadcast_lock, flags);
+
+	cpu = smp_processor_id();
+	td = &per_cpu(tick_cpu_device, cpu);
+	dev = td->evtdev;
+	bc = tick_broadcast_device.evtdev;
+
+	/*
+	 * Is the device in broadcast mode forever or is it not
+	 * affected by the powerstate ?
+	 */
+	if (!dev || !tick_device_is_functional(dev) ||
+	    !(dev->features & CLOCK_EVT_FEAT_C3STOP))
+		goto out;
+
+	if (*reason == CLOCK_EVT_NOTIFY_BROADCAST_ON) {
+		if (!cpu_isset(cpu, tick_broadcast_mask)) {
+			cpu_set(cpu, tick_broadcast_mask);
+			if (td->mode == TICKDEV_MODE_PERIODIC)
+				clockevents_set_mode(dev,
+						     CLOCK_EVT_MODE_SHUTDOWN);
+		}
+	} else {
+		if (cpu_isset(cpu, tick_broadcast_mask)) {
+			cpu_clear(cpu, tick_broadcast_mask);
+			if (td->mode == TICKDEV_MODE_PERIODIC)
+				tick_setup_periodic(dev, 0);
+		}
+	}
+
+	if (cpus_empty(tick_broadcast_mask))
+		clockevents_set_mode(bc, CLOCK_EVT_MODE_SHUTDOWN);
+	else {
+		if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC)
+			tick_broadcast_start_periodic(bc);
+		else
+			tick_broadcast_setup_oneshot(bc);
+	}
+out:
+	spin_unlock_irqrestore(&tick_broadcast_lock, flags);
+}
+
+/*
+ * Powerstate information: The system enters/leaves a state, where
+ * affected devices might stop.
+ */
+void tick_broadcast_on_off(unsigned long reason, int *oncpu)
+{
+	int cpu = get_cpu();
+
+	if (cpu == *oncpu)
+		tick_do_broadcast_on_off(&reason);
+	else
+		smp_call_function_single(*oncpu, tick_do_broadcast_on_off,
+					 &reason, 1, 1);
+	put_cpu();
+}
+
+/*
+ * Set the periodic handler depending on broadcast on/off
+ */
+void tick_set_periodic_handler(struct clock_event_device *dev, int broadcast)
+{
+	if (!broadcast)
+		dev->event_handler = tick_handle_periodic;
+	else
+		dev->event_handler = tick_handle_periodic_broadcast;
+}
+
+/*
+ * Remove a CPU from broadcasting
+ */
+void tick_shutdown_broadcast(unsigned int *cpup)
+{
+	struct clock_event_device *bc;
+	unsigned long flags;
+	unsigned int cpu = *cpup;
+
+	spin_lock_irqsave(&tick_broadcast_lock, flags);
+
+	bc = tick_broadcast_device.evtdev;
+	cpu_clear(cpu, tick_broadcast_mask);
+
+	if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC) {
+		if (bc && cpus_empty(tick_broadcast_mask))
+			clockevents_set_mode(bc, CLOCK_EVT_MODE_SHUTDOWN);
+	}
+
+	spin_unlock_irqrestore(&tick_broadcast_lock, flags);
+}
+
+#ifdef CONFIG_TICK_ONESHOT
+
+static cpumask_t tick_broadcast_oneshot_mask;
+
+/*
+ * Debugging: see timer_list.c
+ */
+cpumask_t *tick_get_broadcast_oneshot_mask(void)
+{
+	return &tick_broadcast_oneshot_mask;
+}
+
+static int tick_broadcast_set_event(ktime_t expires, int force)
+{
+	struct clock_event_device *bc = tick_broadcast_device.evtdev;
+	ktime_t now = ktime_get();
+	int res;
+
+	for(;;) {
+		res = clockevents_program_event(bc, expires, now);
+		if (!res || !force)
+			return res;
+		now = ktime_get();
+		expires = ktime_add(now, ktime_set(0, bc->min_delta_ns));
+	}
+}
+
+/*
+ * Reprogram the broadcast device:
+ *
+ * Called with tick_broadcast_lock held and interrupts disabled.
+ */
+static int tick_broadcast_reprogram(void)
+{
+	ktime_t expires = { .tv64 = KTIME_MAX };
+	struct tick_device *td;
+	int cpu;
+
+	/*
+	 * Find the event which expires next:
+	 */
+	for (cpu = first_cpu(tick_broadcast_oneshot_mask); cpu != NR_CPUS;
+	     cpu = next_cpu(cpu, tick_broadcast_oneshot_mask)) {
+		td = &per_cpu(tick_cpu_device, cpu);
+		if (td->evtdev->next_event.tv64 < expires.tv64)
+			expires = td->evtdev->next_event;
+	}
+
+	if (expires.tv64 == KTIME_MAX)
+		return 0;
+
+	return tick_broadcast_set_event(expires, 0);
+}
+
+/*
+ * Handle oneshot mode broadcasting
+ */
+static void tick_handle_oneshot_broadcast(struct clock_event_device *dev)
+{
+	struct tick_device *td;
+	cpumask_t mask;
+	ktime_t now;
+	int cpu;
+
+	spin_lock(&tick_broadcast_lock);
+again:
+	dev->next_event.tv64 = KTIME_MAX;
+	mask = CPU_MASK_NONE;
+	now = ktime_get();
+	/* Find all expired events */
+	for (cpu = first_cpu(tick_broadcast_oneshot_mask); cpu != NR_CPUS;
+	     cpu = next_cpu(cpu, tick_broadcast_oneshot_mask)) {
+		td = &per_cpu(tick_cpu_device, cpu);
+		if (td->evtdev->next_event.tv64 <= now.tv64)
+			cpu_set(cpu, mask);
+	}
+
+	/*
+	 * Wakeup the cpus which have an expired event. The broadcast
+	 * device is reprogrammed in the return from idle code.
+	 */
+	if (!tick_do_broadcast(mask)) {
+		/*
+		 * The global event did not expire any CPU local
+		 * events. This happens in dyntick mode, as the
+		 * maximum PIT delta is quite small.
+		 */
+		if (tick_broadcast_reprogram())
+			goto again;
+	}
+	spin_unlock(&tick_broadcast_lock);
+}
+
+/*
+ * Powerstate information: The system enters/leaves a state, where
+ * affected devices might stop
+ */
+void tick_broadcast_oneshot_control(unsigned long reason)
+{
+	struct clock_event_device *bc, *dev;
+	struct tick_device *td;
+	unsigned long flags;
+	int cpu;
+
+	spin_lock_irqsave(&tick_broadcast_lock, flags);
+
+	/*
+	 * Periodic mode does not care about the enter/exit of power
+	 * states
+	 */
+	if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC)
+		goto out;
+
+	bc = tick_broadcast_device.evtdev;
+	cpu = smp_processor_id();
+	td = &per_cpu(tick_cpu_device, cpu);
+	dev = td->evtdev;
+
+	if (!(dev->features & CLOCK_EVT_FEAT_C3STOP))
+		goto out;
+
+	if (reason == CLOCK_EVT_NOTIFY_BROADCAST_ENTER) {
+		if (!cpu_isset(cpu, tick_broadcast_oneshot_mask)) {
+			cpu_set(cpu, tick_broadcast_oneshot_mask);
+			clockevents_set_mode(dev, CLOCK_EVT_MODE_SHUTDOWN);
+			if (dev->next_event.tv64 < bc->next_event.tv64)
+				tick_broadcast_set_event(dev->next_event, 1);
+		}
+	} else {
+		if (cpu_isset(cpu, tick_broadcast_oneshot_mask)) {
+			cpu_clear(cpu, tick_broadcast_oneshot_mask);
+			clockevents_set_mode(dev, CLOCK_EVT_MODE_ONESHOT);
+			if (dev->next_event.tv64 != KTIME_MAX)
+				tick_program_event(dev->next_event, 1);
+		}
+	}
+
+out:
+	spin_unlock_irqrestore(&tick_broadcast_lock, flags);
+}
+
+/**
+ * tick_broadcast_setup_highres - setup the broadcast device for highres
+ */
+void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
+{
+	if (bc->mode != CLOCK_EVT_MODE_ONESHOT) {
+		bc->event_handler = tick_handle_oneshot_broadcast;
+		clockevents_set_mode(bc, CLOCK_EVT_MODE_ONESHOT);
+		bc->next_event.tv64 = KTIME_MAX;
+	}
+}
+
+/*
+ * Select oneshot operating mode for the broadcast device
+ */
+void tick_broadcast_switch_to_oneshot(void)
+{
+	struct clock_event_device *bc;
+	unsigned long flags;
+
+	spin_lock_irqsave(&tick_broadcast_lock, flags);
+
+	tick_broadcast_device.mode = TICKDEV_MODE_ONESHOT;
+	bc = tick_broadcast_device.evtdev;
+	if (bc)
+		tick_broadcast_setup_oneshot(bc);
+	spin_unlock_irqrestore(&tick_broadcast_lock, flags);
+}
+
+
+/*
+ * Remove a dead CPU from broadcasting
+ */
+void tick_shutdown_broadcast_oneshot(unsigned int *cpup)
+{
+	struct clock_event_device *bc;
+	unsigned long flags;
+	unsigned int cpu = *cpup;
+
+	spin_lock_irqsave(&tick_broadcast_lock, flags);
+
+	bc = tick_broadcast_device.evtdev;
+	cpu_clear(cpu, tick_broadcast_oneshot_mask);
+
+	if (tick_broadcast_device.mode == TICKDEV_MODE_ONESHOT) {
+		if (bc && cpus_empty(tick_broadcast_oneshot_mask))
+			clockevents_set_mode(bc, CLOCK_EVT_MODE_SHUTDOWN);
+	}
+
+	spin_unlock_irqrestore(&tick_broadcast_lock, flags);
+}
+
+#endif
diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
new file mode 100644
index 00000000000..4500e347f1b
--- /dev/null
+++ b/kernel/time/tick-common.c
@@ -0,0 +1,346 @@
+/*
+ * linux/kernel/time/tick-common.c
+ *
+ * This file contains the base functions to manage periodic tick
+ * related events.
+ *
+ * Copyright(C) 2005-2006, Thomas Gleixner <tglx@linutronix.de>
+ * Copyright(C) 2005-2007, Red Hat, Inc., Ingo Molnar
+ * Copyright(C) 2006-2007, Timesys Corp., Thomas Gleixner
+ *
+ * This code is licenced under the GPL version 2. For details see
+ * kernel-base/COPYING.
+ */
+#include <linux/cpu.h>
+#include <linux/err.h>
+#include <linux/hrtimer.h>
+#include <linux/irq.h>
+#include <linux/percpu.h>
+#include <linux/profile.h>
+#include <linux/sched.h>
+#include <linux/tick.h>
+
+#include "tick-internal.h"
+
+/*
+ * Tick devices
+ */
+DEFINE_PER_CPU(struct tick_device, tick_cpu_device);
+/*
+ * Tick next event: keeps track of the tick time
+ */
+ktime_t tick_next_period;
+ktime_t tick_period;
+static int tick_do_timer_cpu = -1;
+DEFINE_SPINLOCK(tick_device_lock);
+
+/*
+ * Debugging: see timer_list.c
+ */
+struct tick_device *tick_get_device(int cpu)
+{
+	return &per_cpu(tick_cpu_device, cpu);
+}
+
+/**
+ * tick_is_oneshot_available - check for a oneshot capable event device
+ */
+int tick_is_oneshot_available(void)
+{
+	struct clock_event_device *dev = __get_cpu_var(tick_cpu_device).evtdev;
+
+	return dev && (dev->features & CLOCK_EVT_FEAT_ONESHOT);
+}
+
+/*
+ * Periodic tick
+ */
+static void tick_periodic(int cpu)
+{
+	if (tick_do_timer_cpu == cpu) {
+		write_seqlock(&xtime_lock);
+
+		/* Keep track of the next tick event */
+		tick_next_period = ktime_add(tick_next_period, tick_period);
+
+		do_timer(1);
+		write_sequnlock(&xtime_lock);
+	}
+
+	update_process_times(user_mode(get_irq_regs()));
+	profile_tick(CPU_PROFILING);
+}
+
+/*
+ * Event handler for periodic ticks
+ */
+void tick_handle_periodic(struct clock_event_device *dev)
+{
+	int cpu = smp_processor_id();
+
+	tick_periodic(cpu);
+
+	if (dev->mode != CLOCK_EVT_MODE_ONESHOT)
+		return;
+	/*
+	 * Setup the next period for devices, which do not have
+	 * periodic mode:
+	 */
+	for (;;) {
+		ktime_t next = ktime_add(dev->next_event, tick_period);
+
+		if (!clockevents_program_event(dev, next, ktime_get()))
+			return;
+		tick_periodic(cpu);
+	}
+}
+
+/*
+ * Setup the device for a periodic tick
+ */
+void tick_setup_periodic(struct clock_event_device *dev, int broadcast)
+{
+	tick_set_periodic_handler(dev, broadcast);
+
+	/* Broadcast setup ? */
+	if (!tick_device_is_functional(dev))
+		return;
+
+	if (dev->features & CLOCK_EVT_FEAT_PERIODIC) {
+		clockevents_set_mode(dev, CLOCK_EVT_MODE_PERIODIC);
+	} else {
+		unsigned long seq;
+		ktime_t next;
+
+		do {
+			seq = read_seqbegin(&xtime_lock);
+			next = tick_next_period;
+		} while (read_seqretry(&xtime_lock, seq));
+
+		clockevents_set_mode(dev, CLOCK_EVT_MODE_ONESHOT);
+
+		for (;;) {
+			if (!clockevents_program_event(dev, next, ktime_get()))
+				return;
+			next = ktime_add(next, tick_period);
+		}
+	}
+}
+
+/*
+ * Setup the tick device
+ */
+static void tick_setup_device(struct tick_device *td,
+			      struct clock_event_device *newdev, int cpu,
+			      cpumask_t cpumask)
+{
+	ktime_t next_event;
+	void (*handler)(struct clock_event_device *) = NULL;
+
+	/*
+	 * First device setup ?
+	 */
+	if (!td->evtdev) {
+		/*
+		 * If no cpu took the do_timer update, assign it to
+		 * this cpu:
+		 */
+		if (tick_do_timer_cpu == -1) {
+			tick_do_timer_cpu = cpu;
+			tick_next_period = ktime_get();
+			tick_period = ktime_set(0, NSEC_PER_SEC / HZ);
+		}
+
+		/*
+		 * Startup in periodic mode first.
+		 */
+		td->mode = TICKDEV_MODE_PERIODIC;
+	} else {
+		handler = td->evtdev->event_handler;
+		next_event = td->evtdev->next_event;
+	}
+
+	td->evtdev = newdev;
+
+	/*
+	 * When the device is not per cpu, pin the interrupt to the
+	 * current cpu:
+	 */
+	if (!cpus_equal(newdev->cpumask, cpumask))
+		irq_set_affinity(newdev->irq, cpumask);
+
+	/*
+	 * When global broadcasting is active, check if the current
+	 * device is registered as a placeholder for broadcast mode.
+	 * This allows us to handle this x86 misfeature in a generic
+	 * way.
+	 */
+	if (tick_device_uses_broadcast(newdev, cpu))
+		return;
+
+	if (td->mode == TICKDEV_MODE_PERIODIC)
+		tick_setup_periodic(newdev, 0);
+	else
+		tick_setup_oneshot(newdev, handler, next_event);
+}
+
+/*
+ * Check, if the new registered device should be used.
+ */
+static int tick_check_new_device(struct clock_event_device *newdev)
+{
+	struct clock_event_device *curdev;
+	struct tick_device *td;
+	int cpu, ret = NOTIFY_OK;
+	unsigned long flags;
+	cpumask_t cpumask;
+
+	spin_lock_irqsave(&tick_device_lock, flags);
+
+	cpu = smp_processor_id();
+	if (!cpu_isset(cpu, newdev->cpumask))
+		goto out;
+
+	td = &per_cpu(tick_cpu_device, cpu);
+	curdev = td->evtdev;
+	cpumask = cpumask_of_cpu(cpu);
+
+	/* cpu local device ? */
+	if (!cpus_equal(newdev->cpumask, cpumask)) {
+
+		/*
+		 * If the cpu affinity of the device interrupt can not
+		 * be set, ignore it.
+		 */
+		if (!irq_can_set_affinity(newdev->irq))
+			goto out_bc;
+
+		/*
+		 * If we have a cpu local device already, do not replace it
+		 * by a non cpu local device
+		 */
+		if (curdev && cpus_equal(curdev->cpumask, cpumask))
+			goto out_bc;
+	}
+
+	/*
+	 * If we have an active device, then check the rating and the oneshot
+	 * feature.
+	 */
+	if (curdev) {
+		/*
+		 * Prefer one shot capable devices !
+		 */
+		if ((curdev->features & CLOCK_EVT_FEAT_ONESHOT) &&
+		    !(newdev->features & CLOCK_EVT_FEAT_ONESHOT))
+			goto out_bc;
+		/*
+		 * Check the rating
+		 */
+		if (curdev->rating >= newdev->rating)
+			goto out_bc;
+	}
+
+	/*
+	 * Replace the eventually existing device by the new
+	 * device. If the current device is the broadcast device, do
+	 * not give it back to the clockevents layer !
+	 */
+	if (tick_is_broadcast_device(curdev)) {
+		clockevents_set_mode(curdev, CLOCK_EVT_MODE_SHUTDOWN);
+		curdev = NULL;
+	}
+	clockevents_exchange_device(curdev, newdev);
+	tick_setup_device(td, newdev, cpu, cpumask);
+	if (newdev->features & CLOCK_EVT_FEAT_ONESHOT)
+		tick_oneshot_notify();
+
+	spin_unlock_irqrestore(&tick_device_lock, flags);
+	return NOTIFY_STOP;
+
+out_bc:
+	/*
+	 * Can the new device be used as a broadcast device ?
+	 */
+	if (tick_check_broadcast_device(newdev))
+		ret = NOTIFY_STOP;
+out:
+	spin_unlock_irqrestore(&tick_device_lock, flags);
+
+	return ret;
+}
+
+/*
+ * Shutdown an event device on a given cpu:
+ *
+ * This is called on a life CPU, when a CPU is dead. So we cannot
+ * access the hardware device itself.
+ * We just set the mode and remove it from the lists.
+ */
+static void tick_shutdown(unsigned int *cpup)
+{
+	struct tick_device *td = &per_cpu(tick_cpu_device, *cpup);
+	struct clock_event_device *dev = td->evtdev;
+	unsigned long flags;
+
+	spin_lock_irqsave(&tick_device_lock, flags);
+	td->mode = TICKDEV_MODE_PERIODIC;
+	if (dev) {
+		/*
+		 * Prevent that the clock events layer tries to call
+		 * the set mode function!
+		 */
+		dev->mode = CLOCK_EVT_MODE_UNUSED;
+		clockevents_exchange_device(dev, NULL);
+		td->evtdev = NULL;
+	}
+	spin_unlock_irqrestore(&tick_device_lock, flags);
+}
+
+/*
+ * Notification about clock event devices
+ */
+static int tick_notify(struct notifier_block *nb, unsigned long reason,
+			       void *dev)
+{
+	switch (reason) {
+
+	case CLOCK_EVT_NOTIFY_ADD:
+		return tick_check_new_device(dev);
+
+	case CLOCK_EVT_NOTIFY_BROADCAST_ON:
+	case CLOCK_EVT_NOTIFY_BROADCAST_OFF:
+		tick_broadcast_on_off(reason, dev);
+		break;
+
+	case CLOCK_EVT_NOTIFY_BROADCAST_ENTER:
+	case CLOCK_EVT_NOTIFY_BROADCAST_EXIT:
+		tick_broadcast_oneshot_control(reason);
+		break;
+
+	case CLOCK_EVT_NOTIFY_CPU_DEAD:
+		tick_shutdown_broadcast_oneshot(dev);
+		tick_shutdown_broadcast(dev);
+		tick_shutdown(dev);
+		break;
+
+	default:
+		break;
+	}
+
+	return NOTIFY_OK;
+}
+
+static struct notifier_block tick_notifier = {
+	.notifier_call = tick_notify,
+};
+
+/**
+ * tick_init - initialize the tick control
+ *
+ * Register the notifier with the clockevents framework
+ */
+void __init tick_init(void)
+{
+	clockevents_register_notifier(&tick_notifier);
+}
diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h
new file mode 100644
index 00000000000..54861a0f29f
--- /dev/null
+++ b/kernel/time/tick-internal.h
@@ -0,0 +1,110 @@
+/*
+ * tick internal variable and functions used by low/high res code
+ */
+DECLARE_PER_CPU(struct tick_device, tick_cpu_device);
+extern spinlock_t tick_device_lock;
+extern ktime_t tick_next_period;
+extern ktime_t tick_period;
+
+extern void tick_setup_periodic(struct clock_event_device *dev, int broadcast);
+extern void tick_handle_periodic(struct clock_event_device *dev);
+
+/*
+ * NO_HZ / high resolution timer shared code
+ */
+#ifdef CONFIG_TICK_ONESHOT
+extern void tick_setup_oneshot(struct clock_event_device *newdev,
+			       void (*handler)(struct clock_event_device *),
+			       ktime_t nextevt);
+extern int tick_program_event(ktime_t expires, int force);
+extern void tick_oneshot_notify(void);
+extern int tick_switch_to_oneshot(void (*handler)(struct clock_event_device *));
+
+# ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
+extern void tick_broadcast_setup_oneshot(struct clock_event_device *bc);
+extern void tick_broadcast_oneshot_control(unsigned long reason);
+extern void tick_broadcast_switch_to_oneshot(void);
+extern void tick_shutdown_broadcast_oneshot(unsigned int *cpup);
+# else /* BROADCAST */
+static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
+{
+	BUG();
+}
+static inline void tick_broadcast_oneshot_control(unsigned long reason) { }
+static inline void tick_broadcast_switch_to_oneshot(void) { }
+static inline void tick_shutdown_broadcast_oneshot(unsigned int *cpup) { }
+# endif /* !BROADCAST */
+
+#else /* !ONESHOT */
+static inline
+void tick_setup_oneshot(struct clock_event_device *newdev,
+			void (*handler)(struct clock_event_device *),
+			ktime_t nextevt)
+{
+	BUG();
+}
+static inline int tick_program_event(ktime_t expires, int force)
+{
+	return 0;
+}
+static inline void tick_oneshot_notify(void) { }
+static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
+{
+	BUG();
+}
+static inline void tick_broadcast_oneshot_control(unsigned long reason) { }
+static inline void tick_shutdown_broadcast_oneshot(unsigned int *cpup) { }
+#endif /* !TICK_ONESHOT */
+
+/*
+ * Broadcasting support
+ */
+#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
+extern int tick_do_broadcast(cpumask_t mask);
+
+extern int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu);
+extern int tick_check_broadcast_device(struct clock_event_device *dev);
+extern int tick_is_broadcast_device(struct clock_event_device *dev);
+extern void tick_broadcast_on_off(unsigned long reason, int *oncpu);
+extern void tick_shutdown_broadcast(unsigned int *cpup);
+
+extern void
+tick_set_periodic_handler(struct clock_event_device *dev, int broadcast);
+
+#else /* !BROADCAST */
+
+static inline int tick_check_broadcast_device(struct clock_event_device *dev)
+{
+	return 0;
+}
+
+static inline int tick_is_broadcast_device(struct clock_event_device *dev)
+{
+	return 0;
+}
+static inline int tick_device_uses_broadcast(struct clock_event_device *dev,
+					     int cpu)
+{
+	return 0;
+}
+static inline void tick_do_periodic_broadcast(struct clock_event_device *d) { }
+static inline void tick_broadcast_on_off(unsigned long reason, int *oncpu) { }
+static inline void tick_shutdown_broadcast(unsigned int *cpup) { }
+
+/*
+ * Set the periodic handler in non broadcast mode
+ */
+static inline void tick_set_periodic_handler(struct clock_event_device *dev,
+					     int broadcast)
+{
+	dev->event_handler = tick_handle_periodic;
+}
+#endif /* !BROADCAST */
+
+/*
+ * Check, if the device is functional or a dummy for broadcast
+ */
+static inline int tick_device_is_functional(struct clock_event_device *dev)
+{
+	return !(dev->features & CLOCK_EVT_FEAT_DUMMY);
+}
diff --git a/kernel/time/tick-oneshot.c b/kernel/time/tick-oneshot.c
new file mode 100644
index 00000000000..2e8b7ff863c
--- /dev/null
+++ b/kernel/time/tick-oneshot.c
@@ -0,0 +1,84 @@
+/*
+ * linux/kernel/time/tick-oneshot.c
+ *
+ * This file contains functions which manage high resolution tick
+ * related events.
+ *
+ * Copyright(C) 2005-2006, Thomas Gleixner <tglx@linutronix.de>
+ * Copyright(C) 2005-2007, Red Hat, Inc., Ingo Molnar
+ * Copyright(C) 2006-2007, Timesys Corp., Thomas Gleixner
+ *
+ * This code is licenced under the GPL version 2. For details see
+ * kernel-base/COPYING.
+ */
+#include <linux/cpu.h>
+#include <linux/err.h>
+#include <linux/hrtimer.h>
+#include <linux/irq.h>
+#include <linux/percpu.h>
+#include <linux/profile.h>
+#include <linux/sched.h>
+#include <linux/tick.h>
+
+#include "tick-internal.h"
+
+/**
+ * tick_program_event
+ */
+int tick_program_event(ktime_t expires, int force)
+{
+	struct clock_event_device *dev = __get_cpu_var(tick_cpu_device).evtdev;
+	ktime_t now = ktime_get();
+
+	while (1) {
+		int ret = clockevents_program_event(dev, expires, now);
+
+		if (!ret || !force)
+			return ret;
+		now = ktime_get();
+		expires = ktime_add(now, ktime_set(0, dev->min_delta_ns));
+	}
+}
+
+/**
+ * tick_setup_oneshot - setup the event device for oneshot mode (hres or nohz)
+ */
+void tick_setup_oneshot(struct clock_event_device *newdev,
+			void (*handler)(struct clock_event_device *),
+			ktime_t next_event)
+{
+	newdev->event_handler = handler;
+	clockevents_set_mode(newdev, CLOCK_EVT_MODE_ONESHOT);
+	clockevents_program_event(newdev, next_event, ktime_get());
+}
+
+/**
+ * tick_switch_to_oneshot - switch to oneshot mode
+ */
+int tick_switch_to_oneshot(void (*handler)(struct clock_event_device *))
+{
+	struct tick_device *td = &__get_cpu_var(tick_cpu_device);
+	struct clock_event_device *dev = td->evtdev;
+
+	if (!dev || !(dev->features & CLOCK_EVT_FEAT_ONESHOT) ||
+	    !tick_device_is_functional(dev))
+		return -EINVAL;
+
+	td->mode = TICKDEV_MODE_ONESHOT;
+	dev->event_handler = handler;
+	clockevents_set_mode(dev, CLOCK_EVT_MODE_ONESHOT);
+	tick_broadcast_switch_to_oneshot();
+	return 0;
+}
+
+#ifdef CONFIG_HIGH_RES_TIMERS
+/**
+ * tick_init_highres - switch to high resolution mode
+ *
+ * Called with interrupts disabled.
+ */
+int tick_init_highres(void)
+{
+	return tick_switch_to_oneshot(hrtimer_interrupt);
+}
+#endif
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
new file mode 100644
index 00000000000..95e41f7f850
--- /dev/null
+++ b/kernel/time/tick-sched.c
@@ -0,0 +1,563 @@
+/*
+ *  linux/kernel/time/tick-sched.c
+ *
+ *  Copyright(C) 2005-2006, Thomas Gleixner <tglx@linutronix.de>
+ *  Copyright(C) 2005-2007, Red Hat, Inc., Ingo Molnar
+ *  Copyright(C) 2006-2007  Timesys Corp., Thomas Gleixner
+ *
+ *  No idle tick implementation for low and high resolution timers
+ *
+ *  Started by: Thomas Gleixner and Ingo Molnar
+ *
+ *  For licencing details see kernel-base/COPYING
+ */
+#include <linux/cpu.h>
+#include <linux/err.h>
+#include <linux/hrtimer.h>
+#include <linux/interrupt.h>
+#include <linux/kernel_stat.h>
+#include <linux/percpu.h>
+#include <linux/profile.h>
+#include <linux/sched.h>
+#include <linux/tick.h>
+
+#include "tick-internal.h"
+
+/*
+ * Per cpu nohz control structure
+ */
+static DEFINE_PER_CPU(struct tick_sched, tick_cpu_sched);
+
+/*
+ * The time, when the last jiffy update happened. Protected by xtime_lock.
+ */
+static ktime_t last_jiffies_update;
+
+struct tick_sched *tick_get_tick_sched(int cpu)
+{
+	return &per_cpu(tick_cpu_sched, cpu);
+}
+
+/*
+ * Must be called with interrupts disabled !
+ */
+static void tick_do_update_jiffies64(ktime_t now)
+{
+	unsigned long ticks = 0;
+	ktime_t delta;
+
+	/* Reevalute with xtime_lock held */
+	write_seqlock(&xtime_lock);
+
+	delta = ktime_sub(now, last_jiffies_update);
+	if (delta.tv64 >= tick_period.tv64) {
+
+		delta = ktime_sub(delta, tick_period);
+		last_jiffies_update = ktime_add(last_jiffies_update,
+						tick_period);
+
+		/* Slow path for long timeouts */
+		if (unlikely(delta.tv64 >= tick_period.tv64)) {
+			s64 incr = ktime_to_ns(tick_period);
+
+			ticks = ktime_divns(delta, incr);
+
+			last_jiffies_update = ktime_add_ns(last_jiffies_update,
+							   incr * ticks);
+		}
+		do_timer(++ticks);
+	}
+	write_sequnlock(&xtime_lock);
+}
+
+/*
+ * Initialize and return retrieve the jiffies update.
+ */
+static ktime_t tick_init_jiffy_update(void)
+{
+	ktime_t period;
+
+	write_seqlock(&xtime_lock);
+	/* Did we start the jiffies update yet ? */
+	if (last_jiffies_update.tv64 == 0)
+		last_jiffies_update = tick_next_period;
+	period = last_jiffies_update;
+	write_sequnlock(&xtime_lock);
+	return period;
+}
+
+/*
+ * NOHZ - aka dynamic tick functionality
+ */
+#ifdef CONFIG_NO_HZ
+/*
+ * NO HZ enabled ?
+ */
+static int tick_nohz_enabled __read_mostly  = 1;
+
+/*
+ * Enable / Disable tickless mode
+ */
+static int __init setup_tick_nohz(char *str)
+{
+	if (!strcmp(str, "off"))
+		tick_nohz_enabled = 0;
+	else if (!strcmp(str, "on"))
+		tick_nohz_enabled = 1;
+	else
+		return 0;
+	return 1;
+}
+
+__setup("nohz=", setup_tick_nohz);
+
+/**
+ * tick_nohz_update_jiffies - update jiffies when idle was interrupted
+ *
+ * Called from interrupt entry when the CPU was idle
+ *
+ * In case the sched_tick was stopped on this CPU, we have to check if jiffies
+ * must be updated. Otherwise an interrupt handler could use a stale jiffy
+ * value. We do this unconditionally on any cpu, as we don't know whether the
+ * cpu, which has the update task assigned is in a long sleep.
+ */
+void tick_nohz_update_jiffies(void)
+{
+	int cpu = smp_processor_id();
+	struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
+	unsigned long flags;
+	ktime_t now;
+
+	if (!ts->tick_stopped)
+		return;
+
+	cpu_clear(cpu, nohz_cpu_mask);
+	now = ktime_get();
+
+	local_irq_save(flags);
+	tick_do_update_jiffies64(now);
+	local_irq_restore(flags);
+}
+
+/**
+ * tick_nohz_stop_sched_tick - stop the idle tick from the idle task
+ *
+ * When the next event is more than a tick into the future, stop the idle tick
+ * Called either from the idle loop or from irq_exit() when an idle period was
+ * just interrupted by an interrupt which did not cause a reschedule.
+ */
+void tick_nohz_stop_sched_tick(void)
+{
+	unsigned long seq, last_jiffies, next_jiffies, delta_jiffies, flags;
+	struct tick_sched *ts;
+	ktime_t last_update, expires, now, delta;
+	int cpu;
+
+	local_irq_save(flags);
+
+	cpu = smp_processor_id();
+	ts = &per_cpu(tick_cpu_sched, cpu);
+
+	if (unlikely(ts->nohz_mode == NOHZ_MODE_INACTIVE))
+		goto end;
+
+	if (need_resched())
+		goto end;
+
+	cpu = smp_processor_id();
+	BUG_ON(local_softirq_pending());
+
+	now = ktime_get();
+	/*
+	 * When called from irq_exit we need to account the idle sleep time
+	 * correctly.
+	 */
+	if (ts->tick_stopped) {
+		delta = ktime_sub(now, ts->idle_entrytime);
+		ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta);
+	}
+
+	ts->idle_entrytime = now;
+	ts->idle_calls++;
+
+	/* Read jiffies and the time when jiffies were updated last */
+	do {
+		seq = read_seqbegin(&xtime_lock);
+		last_update = last_jiffies_update;
+		last_jiffies = jiffies;
+	} while (read_seqretry(&xtime_lock, seq));
+
+	/* Get the next timer wheel timer */
+	next_jiffies = get_next_timer_interrupt(last_jiffies);
+	delta_jiffies = next_jiffies - last_jiffies;
+
+	/*
+	 * Do not stop the tick, if we are only one off
+	 * or if the cpu is required for rcu
+	 */
+	if (!ts->tick_stopped && (delta_jiffies == 1 || rcu_needs_cpu(cpu)))
+		goto out;
+
+	/* Schedule the tick, if we are at least one jiffie off */
+	if ((long)delta_jiffies >= 1) {
+
+		if (rcu_needs_cpu(cpu))
+			delta_jiffies = 1;
+		else
+			cpu_set(cpu, nohz_cpu_mask);
+		/*
+		 * nohz_stop_sched_tick can be called several times before
+		 * the nohz_restart_sched_tick is called. This happens when
+		 * interrupts arrive which do not cause a reschedule. In the
+		 * first call we save the current tick time, so we can restart
+		 * the scheduler tick in nohz_restart_sched_tick.
+		 */
+		if (!ts->tick_stopped) {
+			ts->idle_tick = ts->sched_timer.expires;
+			ts->tick_stopped = 1;
+			ts->idle_jiffies = last_jiffies;
+		}
+		/*
+		 * calculate the expiry time for the next timer wheel
+		 * timer
+		 */
+		expires = ktime_add_ns(last_update, tick_period.tv64 *
+				       delta_jiffies);
+		ts->idle_expires = expires;
+		ts->idle_sleeps++;
+
+		if (ts->nohz_mode == NOHZ_MODE_HIGHRES) {
+			hrtimer_start(&ts->sched_timer, expires,
+				      HRTIMER_MODE_ABS);
+			/* Check, if the timer was already in the past */
+			if (hrtimer_active(&ts->sched_timer))
+				goto out;
+		} else if(!tick_program_event(expires, 0))
+				goto out;
+		/*
+		 * We are past the event already. So we crossed a
+		 * jiffie boundary. Update jiffies and raise the
+		 * softirq.
+		 */
+		tick_do_update_jiffies64(ktime_get());
+		cpu_clear(cpu, nohz_cpu_mask);
+	}
+	raise_softirq_irqoff(TIMER_SOFTIRQ);
+out:
+	ts->next_jiffies = next_jiffies;
+	ts->last_jiffies = last_jiffies;
+end:
+	local_irq_restore(flags);
+}
+
+/**
+ * nohz_restart_sched_tick - restart the idle tick from the idle task
+ *
+ * Restart the idle tick when the CPU is woken up from idle
+ */
+void tick_nohz_restart_sched_tick(void)
+{
+	int cpu = smp_processor_id();
+	struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
+	unsigned long ticks;
+	ktime_t now, delta;
+
+	if (!ts->tick_stopped)
+		return;
+
+	/* Update jiffies first */
+	now = ktime_get();
+
+	local_irq_disable();
+	tick_do_update_jiffies64(now);
+	cpu_clear(cpu, nohz_cpu_mask);
+
+	/* Account the idle time */
+	delta = ktime_sub(now, ts->idle_entrytime);
+	ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta);
+
+	/*
+	 * We stopped the tick in idle. Update process times would miss the
+	 * time we slept as update_process_times does only a 1 tick
+	 * accounting. Enforce that this is accounted to idle !
+	 */
+	ticks = jiffies - ts->idle_jiffies;
+	/*
+	 * We might be one off. Do not randomly account a huge number of ticks!
+	 */
+	if (ticks && ticks < LONG_MAX) {
+		add_preempt_count(HARDIRQ_OFFSET);
+		account_system_time(current, HARDIRQ_OFFSET,
+				    jiffies_to_cputime(ticks));
+		sub_preempt_count(HARDIRQ_OFFSET);
+	}
+
+	/*
+	 * Cancel the scheduled timer and restore the tick
+	 */
+	ts->tick_stopped  = 0;
+	hrtimer_cancel(&ts->sched_timer);
+	ts->sched_timer.expires = ts->idle_tick;
+
+	while (1) {
+		/* Forward the time to expire in the future */
+		hrtimer_forward(&ts->sched_timer, now, tick_period);
+
+		if (ts->nohz_mode == NOHZ_MODE_HIGHRES) {
+			hrtimer_start(&ts->sched_timer,
+				      ts->sched_timer.expires,
+				      HRTIMER_MODE_ABS);
+			/* Check, if the timer was already in the past */
+			if (hrtimer_active(&ts->sched_timer))
+				break;
+		} else {
+			if (!tick_program_event(ts->sched_timer.expires, 0))
+				break;
+		}
+		/* Update jiffies and reread time */
+		tick_do_update_jiffies64(now);
+		now = ktime_get();
+	}
+	local_irq_enable();
+}
+
+static int tick_nohz_reprogram(struct tick_sched *ts, ktime_t now)
+{
+	hrtimer_forward(&ts->sched_timer, now, tick_period);
+	return tick_program_event(ts->sched_timer.expires, 0);
+}
+
+/*
+ * The nohz low res interrupt handler
+ */
+static void tick_nohz_handler(struct clock_event_device *dev)
+{
+	struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
+	struct pt_regs *regs = get_irq_regs();
+	ktime_t now = ktime_get();
+
+	dev->next_event.tv64 = KTIME_MAX;
+
+	/* Check, if the jiffies need an update */
+	tick_do_update_jiffies64(now);
+
+	/*
+	 * When we are idle and the tick is stopped, we have to touch
+	 * the watchdog as we might not schedule for a really long
+	 * time. This happens on complete idle SMP systems while
+	 * waiting on the login prompt. We also increment the "start
+	 * of idle" jiffy stamp so the idle accounting adjustment we
+	 * do when we go busy again does not account too much ticks.
+	 */
+	if (ts->tick_stopped) {
+		touch_softlockup_watchdog();
+		ts->idle_jiffies++;
+	}
+
+	update_process_times(user_mode(regs));
+	profile_tick(CPU_PROFILING);
+
+	/* Do not restart, when we are in the idle loop */
+	if (ts->tick_stopped)
+		return;
+
+	while (tick_nohz_reprogram(ts, now)) {
+		now = ktime_get();
+		tick_do_update_jiffies64(now);
+	}
+}
+
+/**
+ * tick_nohz_switch_to_nohz - switch to nohz mode
+ */
+static void tick_nohz_switch_to_nohz(void)
+{
+	struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
+	ktime_t next;
+
+	if (!tick_nohz_enabled)
+		return;
+
+	local_irq_disable();
+	if (tick_switch_to_oneshot(tick_nohz_handler)) {
+		local_irq_enable();
+		return;
+	}
+
+	ts->nohz_mode = NOHZ_MODE_LOWRES;
+
+	/*
+	 * Recycle the hrtimer in ts, so we can share the
+	 * hrtimer_forward with the highres code.
+	 */
+	hrtimer_init(&ts->sched_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+	/* Get the next period */
+	next = tick_init_jiffy_update();
+
+	for (;;) {
+		ts->sched_timer.expires = next;
+		if (!tick_program_event(next, 0))
+			break;
+		next = ktime_add(next, tick_period);
+	}
+	local_irq_enable();
+
+	printk(KERN_INFO "Switched to NOHz mode on CPU #%d\n",
+	       smp_processor_id());
+}
+
+#else
+
+static inline void tick_nohz_switch_to_nohz(void) { }
+
+#endif /* NO_HZ */
+
+/*
+ * High resolution timer specific code
+ */
+#ifdef CONFIG_HIGH_RES_TIMERS
+/*
+ * We rearm the timer until we get disabled by the idle code
+ * Called with interrupts disabled and timer->base->cpu_base->lock held.
+ */
+static enum hrtimer_restart tick_sched_timer(struct hrtimer *timer)
+{
+	struct tick_sched *ts =
+		container_of(timer, struct tick_sched, sched_timer);
+	struct hrtimer_cpu_base *base = timer->base->cpu_base;
+	struct pt_regs *regs = get_irq_regs();
+	ktime_t now = ktime_get();
+
+	/* Check, if the jiffies need an update */
+	tick_do_update_jiffies64(now);
+
+	/*
+	 * Do not call, when we are not in irq context and have
+	 * no valid regs pointer
+	 */
+	if (regs) {
+		/*
+		 * When we are idle and the tick is stopped, we have to touch
+		 * the watchdog as we might not schedule for a really long
+		 * time. This happens on complete idle SMP systems while
+		 * waiting on the login prompt. We also increment the "start of
+		 * idle" jiffy stamp so the idle accounting adjustment we do
+		 * when we go busy again does not account too much ticks.
+		 */
+		if (ts->tick_stopped) {
+			touch_softlockup_watchdog();
+			ts->idle_jiffies++;
+		}
+		/*
+		 * update_process_times() might take tasklist_lock, hence
+		 * drop the base lock. sched-tick hrtimers are per-CPU and
+		 * never accessible by userspace APIs, so this is safe to do.
+		 */
+		spin_unlock(&base->lock);
+		update_process_times(user_mode(regs));
+		profile_tick(CPU_PROFILING);
+		spin_lock(&base->lock);
+	}
+
+	/* Do not restart, when we are in the idle loop */
+	if (ts->tick_stopped)
+		return HRTIMER_NORESTART;
+
+	hrtimer_forward(timer, now, tick_period);
+
+	return HRTIMER_RESTART;
+}
+
+/**
+ * tick_setup_sched_timer - setup the tick emulation timer
+ */
+void tick_setup_sched_timer(void)
+{
+	struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
+	ktime_t now = ktime_get();
+
+	/*
+	 * Emulate tick processing via per-CPU hrtimers:
+	 */
+	hrtimer_init(&ts->sched_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+	ts->sched_timer.function = tick_sched_timer;
+	ts->sched_timer.cb_mode = HRTIMER_CB_IRQSAFE_NO_SOFTIRQ;
+
+	/* Get the next period */
+	ts->sched_timer.expires = tick_init_jiffy_update();
+
+	for (;;) {
+		hrtimer_forward(&ts->sched_timer, now, tick_period);
+		hrtimer_start(&ts->sched_timer, ts->sched_timer.expires,
+			      HRTIMER_MODE_ABS);
+		/* Check, if the timer was already in the past */
+		if (hrtimer_active(&ts->sched_timer))
+			break;
+		now = ktime_get();
+	}
+
+#ifdef CONFIG_NO_HZ
+	if (tick_nohz_enabled)
+		ts->nohz_mode = NOHZ_MODE_HIGHRES;
+#endif
+}
+
+void tick_cancel_sched_timer(int cpu)
+{
+	struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
+
+	if (ts->sched_timer.base)
+		hrtimer_cancel(&ts->sched_timer);
+	ts->tick_stopped = 0;
+	ts->nohz_mode = NOHZ_MODE_INACTIVE;
+}
+#endif /* HIGH_RES_TIMERS */
+
+/**
+ * Async notification about clocksource changes
+ */
+void tick_clock_notify(void)
+{
+	int cpu;
+
+	for_each_possible_cpu(cpu)
+		set_bit(0, &per_cpu(tick_cpu_sched, cpu).check_clocks);
+}
+
+/*
+ * Async notification about clock event changes
+ */
+void tick_oneshot_notify(void)
+{
+	struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
+
+	set_bit(0, &ts->check_clocks);
+}
+
+/**
+ * Check, if a change happened, which makes oneshot possible.
+ *
+ * Called cyclic from the hrtimer softirq (driven by the timer
+ * softirq) allow_nohz signals, that we can switch into low-res nohz
+ * mode, because high resolution timers are disabled (either compile
+ * or runtime).
+ */
+int tick_check_oneshot_change(int allow_nohz)
+{
+	struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
+
+	if (!test_and_clear_bit(0, &ts->check_clocks))
+		return 0;
+
+	if (ts->nohz_mode != NOHZ_MODE_INACTIVE)
+		return 0;
+
+	if (!timekeeping_is_continuous() || !tick_is_oneshot_available())
+		return 0;
+
+	if (!allow_nohz)
+		return 1;
+
+	tick_nohz_switch_to_nohz();
+	return 0;
+}
diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c
new file mode 100644
index 00000000000..f82c635c3d5
--- /dev/null
+++ b/kernel/time/timer_list.c
@@ -0,0 +1,287 @@
+/*
+ * kernel/time/timer_list.c
+ *
+ * List pending timers
+ *
+ * Copyright(C) 2006, Red Hat, Inc., Ingo Molnar
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/proc_fs.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/sched.h>
+#include <linux/seq_file.h>
+#include <linux/kallsyms.h>
+#include <linux/tick.h>
+
+#include <asm/uaccess.h>
+
+typedef void (*print_fn_t)(struct seq_file *m, unsigned int *classes);
+
+DECLARE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases);
+
+/*
+ * This allows printing both to /proc/timer_list and
+ * to the console (on SysRq-Q):
+ */
+#define SEQ_printf(m, x...)			\
+ do {						\
+	if (m)					\
+		seq_printf(m, x);		\
+	else					\
+		printk(x);			\
+ } while (0)
+
+static void print_name_offset(struct seq_file *m, void *sym)
+{
+	unsigned long addr = (unsigned long)sym;
+	char namebuf[KSYM_NAME_LEN+1];
+	unsigned long size, offset;
+	const char *sym_name;
+	char *modname;
+
+	sym_name = kallsyms_lookup(addr, &size, &offset, &modname, namebuf);
+	if (sym_name)
+		SEQ_printf(m, "%s", sym_name);
+	else
+		SEQ_printf(m, "<%p>", sym);
+}
+
+static void
+print_timer(struct seq_file *m, struct hrtimer *timer, int idx, u64 now)
+{
+#ifdef CONFIG_TIMER_STATS
+	char tmp[TASK_COMM_LEN + 1];
+#endif
+	SEQ_printf(m, " #%d: ", idx);
+	print_name_offset(m, timer);
+	SEQ_printf(m, ", ");
+	print_name_offset(m, timer->function);
+	SEQ_printf(m, ", S:%02lx", timer->state);
+#ifdef CONFIG_TIMER_STATS
+	SEQ_printf(m, ", ");
+	print_name_offset(m, timer->start_site);
+	memcpy(tmp, timer->start_comm, TASK_COMM_LEN);
+	tmp[TASK_COMM_LEN] = 0;
+	SEQ_printf(m, ", %s/%d", tmp, timer->start_pid);
+#endif
+	SEQ_printf(m, "\n");
+	SEQ_printf(m, " # expires at %Ld nsecs [in %Ld nsecs]\n",
+		(unsigned long long)ktime_to_ns(timer->expires),
+		(unsigned long long)(ktime_to_ns(timer->expires) - now));
+}
+
+static void
+print_active_timers(struct seq_file *m, struct hrtimer_clock_base *base,
+		    u64 now)
+{
+	struct hrtimer *timer, tmp;
+	unsigned long next = 0, i;
+	struct rb_node *curr;
+	unsigned long flags;
+
+next_one:
+	i = 0;
+	spin_lock_irqsave(&base->cpu_base->lock, flags);
+
+	curr = base->first;
+	/*
+	 * Crude but we have to do this O(N*N) thing, because
+	 * we have to unlock the base when printing:
+	 */
+	while (curr && i < next) {
+		curr = rb_next(curr);
+		i++;
+	}
+
+	if (curr) {
+
+		timer = rb_entry(curr, struct hrtimer, node);
+		tmp = *timer;
+		spin_unlock_irqrestore(&base->cpu_base->lock, flags);
+
+		print_timer(m, &tmp, i, now);
+		next++;
+		goto next_one;
+	}
+	spin_unlock_irqrestore(&base->cpu_base->lock, flags);
+}
+
+static void
+print_base(struct seq_file *m, struct hrtimer_clock_base *base, u64 now)
+{
+	SEQ_printf(m, "  .index:      %d\n",
+			base->index);
+	SEQ_printf(m, "  .resolution: %Ld nsecs\n",
+			(unsigned long long)ktime_to_ns(base->resolution));
+	SEQ_printf(m,   "  .get_time:   ");
+	print_name_offset(m, base->get_time);
+	SEQ_printf(m,   "\n");
+#ifdef CONFIG_HIGH_RES_TIMERS
+	SEQ_printf(m, "  .offset:     %Ld nsecs\n",
+			ktime_to_ns(base->offset));
+#endif
+	SEQ_printf(m,   "active timers:\n");
+	print_active_timers(m, base, now);
+}
+
+static void print_cpu(struct seq_file *m, int cpu, u64 now)
+{
+	struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu);
+	int i;
+
+	SEQ_printf(m, "\ncpu: %d\n", cpu);
+	for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
+		SEQ_printf(m, " clock %d:\n", i);
+		print_base(m, cpu_base->clock_base + i, now);
+	}
+#define P(x) \
+	SEQ_printf(m, "  .%-15s: %Ld\n", #x, (u64)(cpu_base->x))
+#define P_ns(x) \
+	SEQ_printf(m, "  .%-15s: %Ld nsecs\n", #x, \
+		(u64)(ktime_to_ns(cpu_base->x)))
+
+#ifdef CONFIG_HIGH_RES_TIMERS
+	P_ns(expires_next);
+	P(hres_active);
+	P(nr_events);
+#endif
+#undef P
+#undef P_ns
+
+#ifdef CONFIG_TICK_ONESHOT
+# define P(x) \
+	SEQ_printf(m, "  .%-15s: %Ld\n", #x, (u64)(ts->x))
+# define P_ns(x) \
+	SEQ_printf(m, "  .%-15s: %Ld nsecs\n", #x, \
+		(u64)(ktime_to_ns(ts->x)))
+	{
+		struct tick_sched *ts = tick_get_tick_sched(cpu);
+		P(nohz_mode);
+		P_ns(idle_tick);
+		P(tick_stopped);
+		P(idle_jiffies);
+		P(idle_calls);
+		P(idle_sleeps);
+		P_ns(idle_entrytime);
+		P_ns(idle_sleeptime);
+		P(last_jiffies);
+		P(next_jiffies);
+		P_ns(idle_expires);
+		SEQ_printf(m, "jiffies: %Ld\n", (u64)jiffies);
+	}
+#endif
+
+#undef P
+#undef P_ns
+}
+
+#ifdef CONFIG_GENERIC_CLOCKEVENTS
+static void
+print_tickdevice(struct seq_file *m, struct tick_device *td)
+{
+	struct clock_event_device *dev = td->evtdev;
+
+	SEQ_printf(m, "\nTick Device: mode:     %d\n", td->mode);
+
+	SEQ_printf(m, "Clock Event Device: ");
+	if (!dev) {
+		SEQ_printf(m, "<NULL>\n");
+		return;
+	}
+	SEQ_printf(m, "%s\n", dev->name);
+	SEQ_printf(m, " max_delta_ns:   %ld\n", dev->max_delta_ns);
+	SEQ_printf(m, " min_delta_ns:   %ld\n", dev->min_delta_ns);
+	SEQ_printf(m, " mult:           %ld\n", dev->mult);
+	SEQ_printf(m, " shift:          %d\n", dev->shift);
+	SEQ_printf(m, " mode:           %d\n", dev->mode);
+	SEQ_printf(m, " next_event:     %Ld nsecs\n",
+		   (unsigned long long) ktime_to_ns(dev->next_event));
+
+	SEQ_printf(m, " set_next_event: ");
+	print_name_offset(m, dev->set_next_event);
+	SEQ_printf(m, "\n");
+
+	SEQ_printf(m, " set_mode:       ");
+	print_name_offset(m, dev->set_mode);
+	SEQ_printf(m, "\n");
+
+	SEQ_printf(m, " event_handler:  ");
+	print_name_offset(m, dev->event_handler);
+	SEQ_printf(m, "\n");
+}
+
+static void timer_list_show_tickdevices(struct seq_file *m)
+{
+	int cpu;
+
+#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
+	print_tickdevice(m, tick_get_broadcast_device());
+	SEQ_printf(m, "tick_broadcast_mask: %08lx\n",
+		   tick_get_broadcast_mask()->bits[0]);
+#ifdef CONFIG_TICK_ONESHOT
+	SEQ_printf(m, "tick_broadcast_oneshot_mask: %08lx\n",
+		   tick_get_broadcast_oneshot_mask()->bits[0]);
+#endif
+	SEQ_printf(m, "\n");
+#endif
+	for_each_online_cpu(cpu)
+		   print_tickdevice(m, tick_get_device(cpu));
+	SEQ_printf(m, "\n");
+}
+#else
+static void timer_list_show_tickdevices(struct seq_file *m) { }
+#endif
+
+static int timer_list_show(struct seq_file *m, void *v)
+{
+	u64 now = ktime_to_ns(ktime_get());
+	int cpu;
+
+	SEQ_printf(m, "Timer List Version: v0.3\n");
+	SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES);
+	SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now);
+
+	for_each_online_cpu(cpu)
+		print_cpu(m, cpu, now);
+
+	SEQ_printf(m, "\n");
+	timer_list_show_tickdevices(m);
+
+	return 0;
+}
+
+void sysrq_timer_list_show(void)
+{
+	timer_list_show(NULL, NULL);
+}
+
+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 = {
+	.open		= timer_list_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= seq_release,
+};
+
+static int __init init_timer_list_procfs(void)
+{
+	struct proc_dir_entry *pe;
+
+	pe = create_proc_entry("timer_list", 0644, NULL);
+	if (!pe)
+		return -ENOMEM;
+
+	pe->proc_fops = &timer_list_fops;
+
+	return 0;
+}
+__initcall(init_timer_list_procfs);
diff --git a/kernel/time/timer_stats.c b/kernel/time/timer_stats.c
new file mode 100644
index 00000000000..1bc4882e28e
--- /dev/null
+++ b/kernel/time/timer_stats.c
@@ -0,0 +1,411 @@
+/*
+ * kernel/time/timer_stats.c
+ *
+ * Collect timer usage statistics.
+ *
+ * Copyright(C) 2006, Red Hat, Inc., Ingo Molnar
+ * Copyright(C) 2006 Timesys Corp., Thomas Gleixner <tglx@timesys.com>
+ *
+ * timer_stats is based on timer_top, a similar functionality which was part of
+ * Con Kolivas dyntick patch set. It was developed by Daniel Petrini at the
+ * Instituto Nokia de Tecnologia - INdT - Manaus. timer_top's design was based
+ * on dynamic allocation of the statistics entries and linear search based
+ * lookup combined with a global lock, rather than the static array, hash
+ * and per-CPU locking which is used by timer_stats. It was written for the
+ * pre hrtimer kernel code and therefore did not take hrtimers into account.
+ * Nevertheless it provided the base for the timer_stats implementation and
+ * was a helpful source of inspiration. Kudos to Daniel and the Nokia folks
+ * for this effort.
+ *
+ * timer_top.c is
+ *	Copyright (C) 2005 Instituto Nokia de Tecnologia - INdT - Manaus
+ *	Written by Daniel Petrini <d.pensator@gmail.com>
+ *	timer_top.c was released under the GNU General Public License version 2
+ *
+ * We export the addresses and counting of timer functions being called,
+ * the pid and cmdline from the owner process if applicable.
+ *
+ * Start/stop data collection:
+ * # echo 1[0] >/proc/timer_stats
+ *
+ * Display the information collected so far:
+ * # cat /proc/timer_stats
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/proc_fs.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/sched.h>
+#include <linux/seq_file.h>
+#include <linux/kallsyms.h>
+
+#include <asm/uaccess.h>
+
+/*
+ * This is our basic unit of interest: a timer expiry event identified
+ * by the timer, its start/expire functions and the PID of the task that
+ * started the timer. We count the number of times an event happens:
+ */
+struct entry {
+	/*
+	 * Hash list:
+	 */
+	struct entry		*next;
+
+	/*
+	 * Hash keys:
+	 */
+	void			*timer;
+	void			*start_func;
+	void			*expire_func;
+	pid_t			pid;
+
+	/*
+	 * Number of timeout events:
+	 */
+	unsigned long		count;
+
+	/*
+	 * We save the command-line string to preserve
+	 * this information past task exit:
+	 */
+	char			comm[TASK_COMM_LEN + 1];
+
+} ____cacheline_aligned_in_smp;
+
+/*
+ * Spinlock protecting the tables - not taken during lookup:
+ */
+static DEFINE_SPINLOCK(table_lock);
+
+/*
+ * Per-CPU lookup locks for fast hash lookup:
+ */
+static DEFINE_PER_CPU(spinlock_t, lookup_lock);
+
+/*
+ * Mutex to serialize state changes with show-stats activities:
+ */
+static DEFINE_MUTEX(show_mutex);
+
+/*
+ * Collection status, active/inactive:
+ */
+static int __read_mostly active;
+
+/*
+ * Beginning/end timestamps of measurement:
+ */
+static ktime_t time_start, time_stop;
+
+/*
+ * tstat entry structs only get allocated while collection is
+ * active and never freed during that time - this simplifies
+ * things quite a bit.
+ *
+ * They get freed when a new collection period is started.
+ */
+#define MAX_ENTRIES_BITS	10
+#define MAX_ENTRIES		(1UL << MAX_ENTRIES_BITS)
+
+static unsigned long nr_entries;
+static struct entry entries[MAX_ENTRIES];
+
+static atomic_t overflow_count;
+
+static void reset_entries(void)
+{
+	nr_entries = 0;
+	memset(entries, 0, sizeof(entries));
+	atomic_set(&overflow_count, 0);
+}
+
+static struct entry *alloc_entry(void)
+{
+	if (nr_entries >= MAX_ENTRIES)
+		return NULL;
+
+	return entries + nr_entries++;
+}
+
+/*
+ * The entries are in a hash-table, for fast lookup:
+ */
+#define TSTAT_HASH_BITS		(MAX_ENTRIES_BITS - 1)
+#define TSTAT_HASH_SIZE		(1UL << TSTAT_HASH_BITS)
+#define TSTAT_HASH_MASK		(TSTAT_HASH_SIZE - 1)
+
+#define __tstat_hashfn(entry)						\
+	(((unsigned long)(entry)->timer       ^				\
+	  (unsigned long)(entry)->start_func  ^				\
+	  (unsigned long)(entry)->expire_func ^				\
+	  (unsigned long)(entry)->pid		) & TSTAT_HASH_MASK)
+
+#define tstat_hashentry(entry)	(tstat_hash_table + __tstat_hashfn(entry))
+
+static struct entry *tstat_hash_table[TSTAT_HASH_SIZE] __read_mostly;
+
+static int match_entries(struct entry *entry1, struct entry *entry2)
+{
+	return entry1->timer       == entry2->timer	  &&
+	       entry1->start_func  == entry2->start_func  &&
+	       entry1->expire_func == entry2->expire_func &&
+	       entry1->pid	   == entry2->pid;
+}
+
+/*
+ * Look up whether an entry matching this item is present
+ * in the hash already. Must be called with irqs off and the
+ * lookup lock held:
+ */
+static struct entry *tstat_lookup(struct entry *entry, char *comm)
+{
+	struct entry **head, *curr, *prev;
+
+	head = tstat_hashentry(entry);
+	curr = *head;
+
+	/*
+	 * The fastpath is when the entry is already hashed,
+	 * we do this with the lookup lock held, but with the
+	 * table lock not held:
+	 */
+	while (curr) {
+		if (match_entries(curr, entry))
+			return curr;
+
+		curr = curr->next;
+	}
+	/*
+	 * Slowpath: allocate, set up and link a new hash entry:
+	 */
+	prev = NULL;
+	curr = *head;
+
+	spin_lock(&table_lock);
+	/*
+	 * Make sure we have not raced with another CPU:
+	 */
+	while (curr) {
+		if (match_entries(curr, entry))
+			goto out_unlock;
+
+		prev = curr;
+		curr = curr->next;
+	}
+
+	curr = alloc_entry();
+	if (curr) {
+		*curr = *entry;
+		curr->count = 0;
+		memcpy(curr->comm, comm, TASK_COMM_LEN);
+		if (prev)
+			prev->next = curr;
+		else
+			*head = curr;
+		curr->next = NULL;
+	}
+ out_unlock:
+	spin_unlock(&table_lock);
+
+	return curr;
+}
+
+/**
+ * timer_stats_update_stats - Update the statistics for a timer.
+ * @timer:	pointer to either a timer_list or a hrtimer
+ * @pid:	the pid of the task which set up the timer
+ * @startf:	pointer to the function which did the timer setup
+ * @timerf:	pointer to the timer callback function of the timer
+ * @comm:	name of the process which set up the timer
+ *
+ * When the timer is already registered, then the event counter is
+ * incremented. Otherwise the timer is registered in a free slot.
+ */
+void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
+			      void *timerf, char * comm)
+{
+	/*
+	 * It doesnt matter which lock we take:
+	 */
+	spinlock_t *lock = &per_cpu(lookup_lock, raw_smp_processor_id());
+	struct entry *entry, input;
+	unsigned long flags;
+
+	input.timer = timer;
+	input.start_func = startf;
+	input.expire_func = timerf;
+	input.pid = pid;
+
+	spin_lock_irqsave(lock, flags);
+	if (!active)
+		goto out_unlock;
+
+	entry = tstat_lookup(&input, comm);
+	if (likely(entry))
+		entry->count++;
+	else
+		atomic_inc(&overflow_count);
+
+ out_unlock:
+	spin_unlock_irqrestore(lock, flags);
+}
+
+static void print_name_offset(struct seq_file *m, unsigned long addr)
+{
+	char namebuf[KSYM_NAME_LEN+1];
+	unsigned long size, offset;
+	const char *sym_name;
+	char *modname;
+
+	sym_name = kallsyms_lookup(addr, &size, &offset, &modname, namebuf);
+	if (sym_name)
+		seq_printf(m, "%s", sym_name);
+	else
+		seq_printf(m, "<%p>", (void *)addr);
+}
+
+static int tstats_show(struct seq_file *m, void *v)
+{
+	struct timespec period;
+	struct entry *entry;
+	unsigned long ms;
+	long events = 0;
+	ktime_t time;
+	int i;
+
+	mutex_lock(&show_mutex);
+	/*
+	 * If still active then calculate up to now:
+	 */
+	if (active)
+		time_stop = ktime_get();
+
+	time = ktime_sub(time_stop, time_start);
+
+	period = ktime_to_timespec(time);
+	ms = period.tv_nsec / 1000000;
+
+	seq_puts(m, "Timer Stats Version: v0.1\n");
+	seq_printf(m, "Sample period: %ld.%03ld s\n", period.tv_sec, ms);
+	if (atomic_read(&overflow_count))
+		seq_printf(m, "Overflow: %d entries\n",
+			atomic_read(&overflow_count));
+
+	for (i = 0; i < nr_entries; i++) {
+		entry = entries + i;
+		seq_printf(m, "%4lu, %5d %-16s ",
+				entry->count, entry->pid, entry->comm);
+
+		print_name_offset(m, (unsigned long)entry->start_func);
+		seq_puts(m, " (");
+		print_name_offset(m, (unsigned long)entry->expire_func);
+		seq_puts(m, ")\n");
+
+		events += entry->count;
+	}
+
+	ms += period.tv_sec * 1000;
+	if (!ms)
+		ms = 1;
+
+	if (events && period.tv_sec)
+		seq_printf(m, "%ld total events, %ld.%ld events/sec\n", events,
+			   events / period.tv_sec, events * 1000 / ms);
+	else
+		seq_printf(m, "%ld total events\n", events);
+
+	mutex_unlock(&show_mutex);
+
+	return 0;
+}
+
+/*
+ * After a state change, make sure all concurrent lookup/update
+ * activities have stopped:
+ */
+static void sync_access(void)
+{
+	unsigned long flags;
+	int cpu;
+
+	for_each_online_cpu(cpu) {
+		spin_lock_irqsave(&per_cpu(lookup_lock, cpu), flags);
+		/* nothing */
+		spin_unlock_irqrestore(&per_cpu(lookup_lock, cpu), flags);
+	}
+}
+
+static ssize_t tstats_write(struct file *file, const char __user *buf,
+			    size_t count, loff_t *offs)
+{
+	char ctl[2];
+
+	if (count != 2 || *offs)
+		return -EINVAL;
+
+	if (copy_from_user(ctl, buf, count))
+		return -EFAULT;
+
+	mutex_lock(&show_mutex);
+	switch (ctl[0]) {
+	case '0':
+		if (active) {
+			active = 0;
+			time_stop = ktime_get();
+			sync_access();
+		}
+		break;
+	case '1':
+		if (!active) {
+			reset_entries();
+			time_start = ktime_get();
+			active = 1;
+		}
+		break;
+	default:
+		count = -EINVAL;
+	}
+	mutex_unlock(&show_mutex);
+
+	return count;
+}
+
+static int tstats_open(struct inode *inode, struct file *filp)
+{
+	return single_open(filp, tstats_show, NULL);
+}
+
+static struct file_operations tstats_fops = {
+	.open		= tstats_open,
+	.read		= seq_read,
+	.write		= tstats_write,
+	.llseek		= seq_lseek,
+	.release	= seq_release,
+};
+
+void __init init_timer_stats(void)
+{
+	int cpu;
+
+	for_each_possible_cpu(cpu)
+		spin_lock_init(&per_cpu(lookup_lock, cpu));
+}
+
+static int __init init_tstats_procfs(void)
+{
+	struct proc_dir_entry *pe;
+
+	pe = create_proc_entry("timer_stats", 0644, NULL);
+	if (!pe)
+		return -ENOMEM;
+
+	pe->proc_fops = &tstats_fops;
+
+	return 0;
+}
+__initcall(init_tstats_procfs);
diff --git a/kernel/timer.c b/kernel/timer.c
index 8533c379608..cb1b86a9c52 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -34,6 +34,8 @@
 #include <linux/cpu.h>
 #include <linux/syscalls.h>
 #include <linux/delay.h>
+#include <linux/tick.h>
+#include <linux/kallsyms.h>
 
 #include <asm/uaccess.h>
 #include <asm/unistd.h>
@@ -262,6 +264,18 @@ static void internal_add_timer(tvec_base_t *base, struct timer_list *timer)
 	list_add_tail(&timer->entry, vec);
 }
 
+#ifdef CONFIG_TIMER_STATS
+void __timer_stats_timer_set_start_info(struct timer_list *timer, void *addr)
+{
+	if (timer->start_site)
+		return;
+
+	timer->start_site = addr;
+	memcpy(timer->start_comm, current->comm, TASK_COMM_LEN);
+	timer->start_pid = current->pid;
+}
+#endif
+
 /**
  * init_timer - initialize a timer.
  * @timer: the timer to be initialized
@@ -273,11 +287,16 @@ void fastcall init_timer(struct timer_list *timer)
 {
 	timer->entry.next = NULL;
 	timer->base = __raw_get_cpu_var(tvec_bases);
+#ifdef CONFIG_TIMER_STATS
+	timer->start_site = NULL;
+	timer->start_pid = -1;
+	memset(timer->start_comm, 0, TASK_COMM_LEN);
+#endif
 }
 EXPORT_SYMBOL(init_timer);
 
 static inline void detach_timer(struct timer_list *timer,
-					int clear_pending)
+				int clear_pending)
 {
 	struct list_head *entry = &timer->entry;
 
@@ -324,6 +343,7 @@ int __mod_timer(struct timer_list *timer, unsigned long expires)
 	unsigned long flags;
 	int ret = 0;
 
+	timer_stats_timer_set_start_info(timer);
 	BUG_ON(!timer->function);
 
 	base = lock_timer_base(timer, &flags);
@@ -374,6 +394,7 @@ void add_timer_on(struct timer_list *timer, int cpu)
 	tvec_base_t *base = per_cpu(tvec_bases, cpu);
   	unsigned long flags;
 
+	timer_stats_timer_set_start_info(timer);
   	BUG_ON(timer_pending(timer) || !timer->function);
 	spin_lock_irqsave(&base->lock, flags);
 	timer->base = base;
@@ -406,6 +427,7 @@ int mod_timer(struct timer_list *timer, unsigned long expires)
 {
 	BUG_ON(!timer->function);
 
+	timer_stats_timer_set_start_info(timer);
 	/*
 	 * This is a common optimization triggered by the
 	 * networking code - if the timer is re-modified
@@ -436,6 +458,7 @@ int del_timer(struct timer_list *timer)
 	unsigned long flags;
 	int ret = 0;
 
+	timer_stats_timer_clear_start_info(timer);
 	if (timer_pending(timer)) {
 		base = lock_timer_base(timer, &flags);
 		if (timer_pending(timer)) {
@@ -569,6 +592,8 @@ static inline void __run_timers(tvec_base_t *base)
  			fn = timer->function;
  			data = timer->data;
 
+			timer_stats_account_timer(timer);
+
 			set_running_timer(base, timer);
 			detach_timer(timer, 1);
 			spin_unlock_irq(&base->lock);
@@ -591,105 +616,124 @@ static inline void __run_timers(tvec_base_t *base)
 	spin_unlock_irq(&base->lock);
 }
 
-#ifdef CONFIG_NO_IDLE_HZ
+#if defined(CONFIG_NO_IDLE_HZ) || defined(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.
  */
-unsigned long next_timer_interrupt(void)
+static unsigned long __next_timer_interrupt(tvec_base_t *base)
 {
-	tvec_base_t *base;
-	struct list_head *list;
+	unsigned long timer_jiffies = base->timer_jiffies;
+	unsigned long expires = timer_jiffies + (LONG_MAX >> 1);
+	int index, slot, array, found = 0;
 	struct timer_list *nte;
-	unsigned long expires;
-	unsigned long hr_expires = MAX_JIFFY_OFFSET;
-	ktime_t hr_delta;
 	tvec_t *varray[4];
-	int i, j;
-
-	hr_delta = hrtimer_get_next_event();
-	if (hr_delta.tv64 != KTIME_MAX) {
-		struct timespec tsdelta;
-		tsdelta = ktime_to_timespec(hr_delta);
-		hr_expires = timespec_to_jiffies(&tsdelta);
-		if (hr_expires < 3)
-			return hr_expires + jiffies;
-	}
-	hr_expires += jiffies;
-
-	base = __get_cpu_var(tvec_bases);
-	spin_lock(&base->lock);
-	expires = base->timer_jiffies + (LONG_MAX >> 1);
-	list = NULL;
 
 	/* Look for timer events in tv1. */
-	j = base->timer_jiffies & TVR_MASK;
+	index = slot = timer_jiffies & TVR_MASK;
 	do {
-		list_for_each_entry(nte, base->tv1.vec + j, entry) {
+		list_for_each_entry(nte, base->tv1.vec + slot, entry) {
+			found = 1;
 			expires = nte->expires;
-			if (j < (base->timer_jiffies & TVR_MASK))
-				list = base->tv2.vec + (INDEX(0));
-			goto found;
+			/* Look at the cascade bucket(s)? */
+			if (!index || slot < index)
+				goto cascade;
+			return expires;
 		}
-		j = (j + 1) & TVR_MASK;
-	} while (j != (base->timer_jiffies & TVR_MASK));
+		slot = (slot + 1) & TVR_MASK;
+	} while (slot != index);
+
+cascade:
+	/* Calculate the next cascade event */
+	if (index)
+		timer_jiffies += TVR_SIZE - index;
+	timer_jiffies >>= TVR_BITS;
 
 	/* Check tv2-tv5. */
 	varray[0] = &base->tv2;
 	varray[1] = &base->tv3;
 	varray[2] = &base->tv4;
 	varray[3] = &base->tv5;
-	for (i = 0; i < 4; i++) {
-		j = INDEX(i);
+
+	for (array = 0; array < 4; array++) {
+		tvec_t *varp = varray[array];
+
+		index = slot = timer_jiffies & TVN_MASK;
 		do {
-			if (list_empty(varray[i]->vec + j)) {
-				j = (j + 1) & TVN_MASK;
-				continue;
-			}
-			list_for_each_entry(nte, varray[i]->vec + j, entry)
+			list_for_each_entry(nte, varp->vec + slot, entry) {
+				found = 1;
 				if (time_before(nte->expires, expires))
 					expires = nte->expires;
-			if (j < (INDEX(i)) && i < 3)
-				list = varray[i + 1]->vec + (INDEX(i + 1));
-			goto found;
-		} while (j != (INDEX(i)));
-	}
-found:
-	if (list) {
-		/*
-		 * The search wrapped. We need to look at the next list
-		 * from next tv element that would cascade into tv element
-		 * where we found the timer element.
-		 */
-		list_for_each_entry(nte, list, entry) {
-			if (time_before(nte->expires, expires))
-				expires = nte->expires;
-		}
+			}
+			/*
+			 * Do we still search for the first timer or are
+			 * we looking up the cascade buckets ?
+			 */
+			if (found) {
+				/* Look at the cascade bucket(s)? */
+				if (!index || slot < index)
+					break;
+				return expires;
+			}
+			slot = (slot + 1) & TVN_MASK;
+		} while (slot != index);
+
+		if (index)
+			timer_jiffies += TVN_SIZE - index;
+		timer_jiffies >>= TVN_BITS;
 	}
-	spin_unlock(&base->lock);
+	return expires;
+}
 
-	/*
-	 * It can happen that other CPUs service timer IRQs and increment
-	 * jiffies, but we have not yet got a local timer tick to process
-	 * the timer wheels.  In that case, the expiry time can be before
-	 * jiffies, but since the high-resolution timer here is relative to
-	 * jiffies, the default expression when high-resolution timers are
-	 * not active,
-	 *
-	 *   time_before(MAX_JIFFY_OFFSET + jiffies, expires)
-	 *
-	 * would falsely evaluate to true.  If that is the case, just
-	 * return jiffies so that we can immediately fire the local timer
-	 */
-	if (time_before(expires, jiffies))
-		return jiffies;
+/*
+ * Check, if the next hrtimer event is before the next timer wheel
+ * event:
+ */
+static unsigned long cmp_next_hrtimer_event(unsigned long now,
+					    unsigned long expires)
+{
+	ktime_t hr_delta = hrtimer_get_next_event();
+	struct timespec tsdelta;
+
+	if (hr_delta.tv64 == KTIME_MAX)
+		return expires;
 
-	if (time_before(hr_expires, expires))
-		return hr_expires;
+	if (hr_delta.tv64 <= TICK_NSEC)
+		return now;
 
+	tsdelta = ktime_to_timespec(hr_delta);
+	now += timespec_to_jiffies(&tsdelta);
+	if (time_before(now, expires))
+		return now;
 	return expires;
 }
+
+/**
+ * next_timer_interrupt - return the jiffy of the next pending timer
+ */
+unsigned long get_next_timer_interrupt(unsigned long now)
+{
+	tvec_base_t *base = __get_cpu_var(tvec_bases);
+	unsigned long expires;
+
+	spin_lock(&base->lock);
+	expires = __next_timer_interrupt(base);
+	spin_unlock(&base->lock);
+
+	if (time_before_eq(expires, now))
+		return now;
+
+	return cmp_next_hrtimer_event(now, expires);
+}
+
+#ifdef CONFIG_NO_IDLE_HZ
+unsigned long next_timer_interrupt(void)
+{
+	return get_next_timer_interrupt(jiffies);
+}
+#endif
+
 #endif
 
 /******************************************************************/
@@ -832,32 +876,35 @@ EXPORT_SYMBOL(do_settimeofday);
  *
  * Accumulates current time interval and initializes new clocksource
  */
-static int change_clocksource(void)
+static void change_clocksource(void)
 {
 	struct clocksource *new;
 	cycle_t now;
 	u64 nsec;
+
 	new = clocksource_get_next();
-	if (clock != new) {
-		now = clocksource_read(new);
-		nsec =  __get_nsec_offset();
-		timespec_add_ns(&xtime, nsec);
-
-		clock = new;
-		clock->cycle_last = now;
-		printk(KERN_INFO "Time: %s clocksource has been installed.\n",
-		       clock->name);
-		return 1;
-	} else if (clock->update_callback) {
-		return clock->update_callback();
-	}
-	return 0;
+
+	if (clock == new)
+		return;
+
+	now = clocksource_read(new);
+	nsec =  __get_nsec_offset();
+	timespec_add_ns(&xtime, nsec);
+
+	clock = new;
+	clock->cycle_last = now;
+
+	clock->error = 0;
+	clock->xtime_nsec = 0;
+	clocksource_calculate_interval(clock, NTP_INTERVAL_LENGTH);
+
+	tick_clock_notify();
+
+	printk(KERN_INFO "Time: %s clocksource has been installed.\n",
+	       clock->name);
 }
 #else
-static inline int change_clocksource(void)
-{
-	return 0;
-}
+static inline void change_clocksource(void) { }
 #endif
 
 /**
@@ -871,33 +918,56 @@ int timekeeping_is_continuous(void)
 	do {
 		seq = read_seqbegin(&xtime_lock);
 
-		ret = clock->is_continuous;
+		ret = clock->flags & CLOCK_SOURCE_VALID_FOR_HRES;
 
 	} while (read_seqretry(&xtime_lock, seq));
 
 	return ret;
 }
 
+/**
+ * read_persistent_clock -  Return time in seconds 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.
+ *
+ *  XXX - Do be sure to remove it once all arches implement it.
+ */
+unsigned long __attribute__((weak)) read_persistent_clock(void)
+{
+	return 0;
+}
+
 /*
  * timekeeping_init - Initializes the clocksource and common timekeeping values
  */
 void __init timekeeping_init(void)
 {
 	unsigned long flags;
+	unsigned long sec = read_persistent_clock();
 
 	write_seqlock_irqsave(&xtime_lock, flags);
 
 	ntp_clear();
 
 	clock = clocksource_get_next();
-	clocksource_calculate_interval(clock, tick_nsec);
+	clocksource_calculate_interval(clock, NTP_INTERVAL_LENGTH);
 	clock->cycle_last = clocksource_read(clock);
 
+	xtime.tv_sec = sec;
+	xtime.tv_nsec = 0;
+	set_normalized_timespec(&wall_to_monotonic,
+		-xtime.tv_sec, -xtime.tv_nsec);
+
 	write_sequnlock_irqrestore(&xtime_lock, flags);
 }
 
-
+/* flag for if timekeeping is suspended */
 static int timekeeping_suspended;
+/* time in seconds when suspend began */
+static unsigned long timekeeping_suspend_time;
+
 /**
  * timekeeping_resume - Resumes the generic timekeeping subsystem.
  * @dev:	unused
@@ -909,13 +979,26 @@ static int timekeeping_suspended;
 static int timekeeping_resume(struct sys_device *dev)
 {
 	unsigned long flags;
+	unsigned long now = read_persistent_clock();
 
 	write_seqlock_irqsave(&xtime_lock, flags);
-	/* restart the last cycle value */
+
+	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;
+	}
+	/* re-base the last cycle value */
 	clock->cycle_last = clocksource_read(clock);
 	clock->error = 0;
 	timekeeping_suspended = 0;
 	write_sequnlock_irqrestore(&xtime_lock, flags);
+
+	touch_softlockup_watchdog();
+	/* Resume hrtimers */
+	clock_was_set();
+
 	return 0;
 }
 
@@ -925,6 +1008,7 @@ static int timekeeping_suspend(struct sys_device *dev, pm_message_t state)
 
 	write_seqlock_irqsave(&xtime_lock, flags);
 	timekeeping_suspended = 1;
+	timekeeping_suspend_time = read_persistent_clock();
 	write_sequnlock_irqrestore(&xtime_lock, flags);
 	return 0;
 }
@@ -1089,11 +1173,8 @@ static void update_wall_time(void)
 	clock->xtime_nsec -= (s64)xtime.tv_nsec << clock->shift;
 
 	/* check to see if there is a new clocksource to use */
-	if (change_clocksource()) {
-		clock->error = 0;
-		clock->xtime_nsec = 0;
-		clocksource_calculate_interval(clock, tick_nsec);
-	}
+	change_clocksource();
+	update_vsyscall(&xtime, clock);
 }
 
 /*
@@ -1162,11 +1243,9 @@ static inline void calc_load(unsigned long ticks)
  * This read-write spinlock protects us from races in SMP while
  * playing with xtime and avenrun.
  */
-#ifndef ARCH_HAVE_XTIME_LOCK
-__cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock);
+__attribute__((weak)) __cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock);
 
 EXPORT_SYMBOL(xtime_lock);
-#endif
 
 /*
  * This function runs timers and the timer-tq in bottom half context.
@@ -1175,7 +1254,8 @@ static void run_timer_softirq(struct softirq_action *h)
 {
 	tvec_base_t *base = __get_cpu_var(tvec_bases);
 
- 	hrtimer_run_queues();
+	hrtimer_run_queues();
+
 	if (time_after_eq(jiffies, base->timer_jiffies))
 		__run_timers(base);
 }
@@ -1621,6 +1701,8 @@ void __init init_timers(void)
 	int err = timer_cpu_notify(&timers_nb, (unsigned long)CPU_UP_PREPARE,
 				(void *)(long)smp_processor_id());
 
+	init_timer_stats();
+
 	BUG_ON(err == NOTIFY_BAD);
 	register_cpu_notifier(&timers_nb);
 	open_softirq(TIMER_SOFTIRQ, run_timer_softirq, NULL);
diff --git a/kernel/tsacct.c b/kernel/tsacct.c
index baacc369141..658f638c402 100644
--- a/kernel/tsacct.c
+++ b/kernel/tsacct.c
@@ -22,8 +22,6 @@
 #include <linux/acct.h>
 #include <linux/jiffies.h>
 
-
-#define USEC_PER_TICK	(USEC_PER_SEC/HZ)
 /*
  * fill in basic accounting fields
  */
diff --git a/kernel/utsname_sysctl.c b/kernel/utsname_sysctl.c
new file mode 100644
index 00000000000..f22b9dbd2a9
--- /dev/null
+++ b/kernel/utsname_sysctl.c
@@ -0,0 +1,146 @@
+/*
+ *  Copyright (C) 2007
+ *
+ *  Author: Eric Biederman <ebiederm@xmision.com>
+ *
+ *  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, version 2 of the
+ *  License.
+ */
+
+#include <linux/module.h>
+#include <linux/uts.h>
+#include <linux/utsname.h>
+#include <linux/version.h>
+#include <linux/sysctl.h>
+
+static void *get_uts(ctl_table *table, int write)
+{
+	char *which = table->data;
+#ifdef CONFIG_UTS_NS
+	struct uts_namespace *uts_ns = current->nsproxy->uts_ns;
+	which = (which - (char *)&init_uts_ns) + (char *)uts_ns;
+#endif
+	if (!write)
+		down_read(&uts_sem);
+	else
+		down_write(&uts_sem);
+	return which;
+}
+
+static void put_uts(ctl_table *table, int write, void *which)
+{
+	if (!write)
+		up_read(&uts_sem);
+	else
+		up_write(&uts_sem);
+}
+
+#ifdef CONFIG_PROC_FS
+/*
+ *	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,
+		  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);
+	put_uts(table, write, uts_table.data);
+	return r;
+}
+#else
+#define proc_do_uts_string NULL
+#endif
+
+
+#ifdef CONFIG_SYSCTL_SYSCALL
+/* The generic string strategy routine: */
+static int sysctl_uts_string(ctl_table *table, int __user *name, int nlen,
+		  void __user *oldval, size_t __user *oldlenp,
+		  void __user *newval, size_t newlen)
+{
+	struct ctl_table uts_table;
+	int r, write;
+	write = newval && newlen;
+	memcpy(&uts_table, table, sizeof(uts_table));
+	uts_table.data = get_uts(table, write);
+	r = sysctl_string(&uts_table, name, nlen,
+		oldval, oldlenp, newval, newlen);
+	put_uts(table, write, uts_table.data);
+	return r;
+}
+#else
+#define sysctl_uts_string NULL
+#endif
+
+static struct ctl_table uts_kern_table[] = {
+	{
+		.ctl_name	= KERN_OSTYPE,
+		.procname	= "ostype",
+		.data		= init_uts_ns.name.sysname,
+		.maxlen		= sizeof(init_uts_ns.name.sysname),
+		.mode		= 0444,
+		.proc_handler	= proc_do_uts_string,
+		.strategy	= sysctl_uts_string,
+	},
+	{
+		.ctl_name	= KERN_OSRELEASE,
+		.procname	= "osrelease",
+		.data		= init_uts_ns.name.release,
+		.maxlen		= sizeof(init_uts_ns.name.release),
+		.mode		= 0444,
+		.proc_handler	= proc_do_uts_string,
+		.strategy	= sysctl_uts_string,
+	},
+	{
+		.ctl_name	= KERN_VERSION,
+		.procname	= "version",
+		.data		= init_uts_ns.name.version,
+		.maxlen		= sizeof(init_uts_ns.name.version),
+		.mode		= 0444,
+		.proc_handler	= proc_do_uts_string,
+		.strategy	= sysctl_uts_string,
+	},
+	{
+		.ctl_name	= KERN_NODENAME,
+		.procname	= "hostname",
+		.data		= init_uts_ns.name.nodename,
+		.maxlen		= sizeof(init_uts_ns.name.nodename),
+		.mode		= 0644,
+		.proc_handler	= proc_do_uts_string,
+		.strategy	= sysctl_uts_string,
+	},
+	{
+		.ctl_name	= KERN_DOMAINNAME,
+		.procname	= "domainname",
+		.data		= init_uts_ns.name.domainname,
+		.maxlen		= sizeof(init_uts_ns.name.domainname),
+		.mode		= 0644,
+		.proc_handler	= proc_do_uts_string,
+		.strategy	= sysctl_uts_string,
+	},
+	{}
+};
+
+static struct ctl_table uts_root_table[] = {
+	{
+		.ctl_name	= CTL_KERN,
+		.procname	= "kernel",
+		.mode		= 0555,
+		.child		= uts_kern_table,
+	},
+	{}
+};
+
+static int __init utsname_sysctl_init(void)
+{
+	register_sysctl_table(uts_root_table);
+	return 0;
+}
+
+__initcall(utsname_sysctl_init);
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 020d1fff57d..b6fa5e63085 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -218,7 +218,7 @@ int fastcall queue_work(struct workqueue_struct *wq, struct work_struct *work)
 }
 EXPORT_SYMBOL_GPL(queue_work);
 
-static void delayed_work_timer_fn(unsigned long __data)
+void delayed_work_timer_fn(unsigned long __data)
 {
 	struct delayed_work *dwork = (struct delayed_work *)__data;
 	struct workqueue_struct *wq = get_wq_data(&dwork->work);
@@ -245,6 +245,7 @@ int fastcall queue_delayed_work(struct workqueue_struct *wq,
 	struct timer_list *timer = &dwork->timer;
 	struct work_struct *work = &dwork->work;
 
+	timer_stats_timer_set_start_info(timer);
 	if (delay == 0)
 		return queue_work(wq, work);
 
@@ -593,8 +594,10 @@ EXPORT_SYMBOL(schedule_work);
  * After waiting for a given time this puts a job in the kernel-global
  * workqueue.
  */
-int fastcall schedule_delayed_work(struct delayed_work *dwork, unsigned long delay)
+int fastcall schedule_delayed_work(struct delayed_work *dwork,
+					unsigned long delay)
 {
+	timer_stats_timer_set_start_info(&dwork->timer);
 	return queue_delayed_work(keventd_wq, dwork, delay);
 }
 EXPORT_SYMBOL(schedule_delayed_work);