Commit 6f507102 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 

* 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  hrtimer: Eliminate needless reprogramming of clock events device
parents 73964f6b 7403f41f

kernel/hrtimer.c

+35 −18
Original line number Diff line number Diff line
@@ -509,13 +509,14 @@ static inline int hrtimer_hres_active(void) 
 * next event

 * Called with interrupts disabled and base->lock held

 */

static void hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base)

static void

hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base, int skip_equal)

{

	int i;

	struct hrtimer_clock_base *base = cpu_base->clock_base;

	ktime_t expires;

	ktime_t expires, expires_next;



	cpu_base->expires_next.tv64 = KTIME_MAX;

	expires_next.tv64 = KTIME_MAX;



	for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) {

		struct hrtimer *timer;
@@ -531,10 +532,15 @@ static void hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base) 
		 */

		if (expires.tv64 < 0)

			expires.tv64 = 0;

		if (expires.tv64 < cpu_base->expires_next.tv64)

			cpu_base->expires_next = expires;

		if (expires.tv64 < expires_next.tv64)

			expires_next = expires;

	}



	if (skip_equal && expires_next.tv64 == cpu_base->expires_next.tv64)

		return;



	cpu_base->expires_next.tv64 = expires_next.tv64;



	if (cpu_base->expires_next.tv64 != KTIME_MAX)

		tick_program_event(cpu_base->expires_next, 1);

}
@@ -617,7 +623,7 @@ static void retrigger_next_event(void *arg) 
	base->clock_base[CLOCK_REALTIME].offset =

		timespec_to_ktime(realtime_offset);



	hrtimer_force_reprogram(base);

	hrtimer_force_reprogram(base, 0);

	spin_unlock(&base->lock);

}
@@ -730,7 +736,8 @@ static int hrtimer_switch_to_hres(void) 
static inline int hrtimer_hres_active(void) { return 0; }

static inline int hrtimer_is_hres_enabled(void) { return 0; }

static inline int hrtimer_switch_to_hres(void) { return 0; }

static inline void hrtimer_force_reprogram(struct hrtimer_cpu_base *base) { }

static inline void

hrtimer_force_reprogram(struct hrtimer_cpu_base *base, int skip_equal) { }

static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,

					    struct hrtimer_clock_base *base,

					    int wakeup)
@@ -873,19 +880,29 @@ static void __remove_hrtimer(struct hrtimer *timer, 
			     struct hrtimer_clock_base *base,

			     unsigned long newstate, int reprogram)

{

	if (timer->state & HRTIMER_STATE_ENQUEUED) {

	if (!(timer->state & HRTIMER_STATE_ENQUEUED))

		goto out;



	/*

		 * Remove the timer from the rbtree and replace the

		 * first entry pointer if necessary.

	 * Remove the timer from the rbtree and replace the first

	 * entry pointer if necessary.

	 */

	if (base->first == &timer->node) {

		base->first = rb_next(&timer->node);

#ifdef CONFIG_HIGH_RES_TIMERS

		/* Reprogram the clock event device. if enabled */

			if (reprogram && hrtimer_hres_active())

				hrtimer_force_reprogram(base->cpu_base);

		if (reprogram && hrtimer_hres_active()) {

			ktime_t expires;



			expires = ktime_sub(hrtimer_get_expires(timer),

					    base->offset);

			if (base->cpu_base->expires_next.tv64 == expires.tv64)

				hrtimer_force_reprogram(base->cpu_base, 1);

		}

		rb_erase(&timer->node, &base->active);

#endif

	}

	rb_erase(&timer->node, &base->active);

out:

	timer->state = newstate;

}