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Commit de27e145 authored by Viresh Kumar's avatar Viresh Kumar Committed by Satya Durga Srinivasu Prabhala
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hrtimer: update timer->state with 'pinned' information 



'Pinned' information would be required in migrate_hrtimers() now, as we can
migrate non-pinned timers away without a hotplug (i.e. with cpuset.quiesce). And
so we may need to identify pinned timers now, as we can't migrate them.

This patch reuses the timer->state variable for setting this flag as there were
enough number of free bits available in this variable. And there is no point
increasing size of this struct by adding another field.

Change-Id: Id2cdd74903598e31fab6999c4cbab9c2fd17fe23
Signed-off-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
[forward port to 3.18]
Signed-off-by: default avatarSantosh Shukla <santosh.shukla@linaro.org>
[ohaugan@codeaurora.org: Port to 4.4]
Git-commit: 62feaf1ed0b64c04868d143d8bdb92d60dc3189b
Git-repo: git://git.linaro.org/people/mike.holmes/santosh.shukla/lng-isol.git


Signed-off-by: default avatarOlav Haugan <ohaugan@codeaurora.org>
[markivx: Port to 4.14, fix merge conflicts due to lack of timer stats code]
Signed-off-by: default avatarVikram Mulukutla <markivx@codeaurora.org>
[satyap@codeaurora.org: Port to 4.19, fix merge conflicts]
Signed-off-by: default avatarSatya Durga Srinivasu Prabhala <satyap@codeaurora.org>
parent 23a5e1f9

include/linux/hrtimer.h

+3 −0
Original line number Diff line number Diff line
@@ -68,6 +68,7 @@ enum hrtimer_restart { 
 *

 * 0x00		inactive

 * 0x01		enqueued into rbtree

 * 0x02		timer is pinned to a cpu

 *

 * The callback state is not part of the timer->state because clearing it would

 * mean touching the timer after the callback, this makes it impossible to free
@@ -87,6 +88,8 @@ enum hrtimer_restart { 
 */

#define HRTIMER_STATE_INACTIVE	0x00

#define HRTIMER_STATE_ENQUEUED	0x01

#define HRTIMER_PINNED_SHIFT	1

#define HRTIMER_STATE_PINNED	(1 << HRTIMER_PINNED_SHIFT)



/**

 * struct hrtimer - the basic hrtimer structure

kernel/time/hrtimer.c

+14 −5
Original line number Diff line number Diff line
@@ -955,7 +955,7 @@ static int enqueue_hrtimer(struct hrtimer *timer, 


	base->cpu_base->active_bases |= 1 << base->index;



	timer->state = HRTIMER_STATE_ENQUEUED;

	timer->state |= HRTIMER_STATE_ENQUEUED;



	return timerqueue_add(&base->active, &timer->node);

}
@@ -975,11 +975,9 @@ static void __remove_hrtimer(struct hrtimer *timer, 
			     u8 newstate, int reprogram)

{

	struct hrtimer_cpu_base *cpu_base = base->cpu_base;

	u8 state = timer->state;



	timer->state = newstate;

	if (!(state & HRTIMER_STATE_ENQUEUED))

		return;

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

		goto out;



	if (!timerqueue_del(&base->active, &timer->node))

		cpu_base->active_bases &= ~(1 << base->index);
@@ -994,6 +992,13 @@ static void __remove_hrtimer(struct hrtimer *timer, 
	 */

	if (reprogram && timer == cpu_base->next_timer)

		hrtimer_force_reprogram(cpu_base, 1);



out:

	/*

	* We need to preserve PINNED state here, otherwise we may end up

	* migrating pinned hrtimers as well.

	*/

	timer->state = newstate | (timer->state & HRTIMER_STATE_PINNED);

}



/*
@@ -1086,6 +1091,10 @@ static int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, 
	/* Switch the timer base, if necessary: */

	new_base = switch_hrtimer_base(timer, base, mode & HRTIMER_MODE_PINNED);



	/* Update pinned state */

	timer->state &= ~HRTIMER_STATE_PINNED;

	timer->state |= !!(mode & HRTIMER_MODE_PINNED) << HRTIMER_PINNED_SHIFT;



	return enqueue_hrtimer(timer, new_base, mode);

}