Commit 2e09bf55 authored by Ingo Molnar's avatar Ingo Molnar
Browse files

sched: wakeup granularity increase 



increase wakeup granularity - we were overscheduling a bit.

Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: default avatarMike Galbraith <efault@gmx.de>
parent 5c6b5964

kernel/sched_fair.c

+11 −16
Original line number Diff line number Diff line
@@ -74,7 +74,7 @@ const_debug unsigned int sysctl_sched_batch_wakeup_granularity = 25000000UL; 
 * and reduces their over-scheduling. Synchronous workloads will still

 * have immediate wakeup/sleep latencies.

 */

const_debug unsigned int sysctl_sched_wakeup_granularity = 1000000UL;

const_debug unsigned int sysctl_sched_wakeup_granularity = 2000000UL;



unsigned int sysctl_sched_runtime_limit __read_mostly;
@@ -582,7 +582,7 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep) 
 * Preempt the current task with a newly woken task if needed:

 */

static void

__check_preempt_curr_fair(struct cfs_rq *cfs_rq, struct sched_entity *curr)

check_preempt_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr)

{

	unsigned long ideal_runtime, delta_exec;
@@ -646,8 +646,6 @@ static void put_prev_entity(struct cfs_rq *cfs_rq, struct sched_entity *prev) 


static void entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr)

{

	struct sched_entity *next;



	/*

	 * Dequeue and enqueue the task to update its

	 * position within the tree:
@@ -655,14 +653,8 @@ static void entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr) 
	dequeue_entity(cfs_rq, curr, 0);

	enqueue_entity(cfs_rq, curr, 0);



	/*

	 * Reschedule if another task tops the current one.

	 */

	next = __pick_next_entity(cfs_rq);

	if (next == curr)

		return;



	__check_preempt_curr_fair(cfs_rq, curr);

	if (cfs_rq->nr_running > 1)

		check_preempt_tick(cfs_rq, curr);

}



/**************************************************
@@ -852,7 +844,7 @@ static void yield_task_fair(struct rq *rq, struct task_struct *p) 
/*

 * Preempt the current task with a newly woken task if needed:

 */

static void check_preempt_curr_fair(struct rq *rq, struct task_struct *p)

static void check_preempt_wakeup(struct rq *rq, struct task_struct *p)

{

	struct task_struct *curr = rq->curr;

	struct cfs_rq *cfs_rq = task_cfs_rq(curr);
@@ -863,9 +855,12 @@ static void check_preempt_curr_fair(struct rq *rq, struct task_struct *p) 
		resched_task(curr);

		return;

	}

	if (is_same_group(curr, p)) {

		s64 delta = curr->se.vruntime - p->se.vruntime;



	if (is_same_group(curr, p))

		__check_preempt_curr_fair(cfs_rq, &curr->se);

		if (delta > (s64)sysctl_sched_wakeup_granularity)

			resched_task(curr);

	}

}



static struct task_struct *pick_next_task_fair(struct rq *rq)
@@ -1095,7 +1090,7 @@ struct sched_class fair_sched_class __read_mostly = { 
	.dequeue_task		= dequeue_task_fair,

	.yield_task		= yield_task_fair,



	.check_preempt_curr	= check_preempt_curr_fair,

	.check_preempt_curr	= check_preempt_wakeup,



	.pick_next_task		= pick_next_task_fair,

	.put_prev_task		= put_prev_task_fair,