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Commit 3b640894 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

sched: Optimize cgroup vs wakeup a bit 



We don't need to call update_shares() for each domain we iterate,
just got the largets one.

However, we should call it before wake_affine() as well, so that
that can use up-to-date values too.

Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 7c423e98

kernel/sched.c

+0 −7
Original line number Diff line number Diff line
@@ -376,13 +376,6 @@ static inline void set_task_rq(struct task_struct *p, unsigned int cpu) 


#else



#ifdef CONFIG_SMP

static int root_task_group_empty(void)

{

	return 1;

}

#endif



static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { }

static inline struct task_group *task_group(struct task_struct *p)

{

kernel/sched_fair.c

+9 −14
Original line number Diff line number Diff line
@@ -1348,7 +1348,7 @@ find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu) 
 */

static int select_task_rq_fair(struct task_struct *p, int sd_flag, int flags)

{

	struct sched_domain *tmp, *sd = NULL;

	struct sched_domain *tmp, *shares = NULL, *sd = NULL;

	int cpu = smp_processor_id();

	int prev_cpu = task_cpu(p);

	int new_cpu = cpu;
@@ -1387,22 +1387,14 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int flags) 
				break;

		}



		switch (sd_flag) {

		case SD_BALANCE_WAKE:

			if (!sched_feat(LB_WAKEUP_UPDATE))

				break;

		case SD_BALANCE_FORK:

		case SD_BALANCE_EXEC:

			if (root_task_group_empty())

				break;

			update_shares(tmp);

		default:

			break;

		}



		if (want_affine && (tmp->flags & SD_WAKE_AFFINE) &&

		    cpumask_test_cpu(prev_cpu, sched_domain_span(tmp))) {



			if (sched_feat(LB_SHARES_UPDATE)) {

				update_shares(tmp);

				shares = tmp;

			}



			if (wake_affine(tmp, p, sync)) {

				new_cpu = cpu;

				goto out;
@@ -1417,6 +1409,9 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int flags) 
		sd = tmp;

	}



	if (sd && sd != shares && sched_feat(LB_SHARES_UPDATE))

		update_shares(sd);



	while (sd) {

		struct sched_group *group;

		int weight;

kernel/sched_features.h

+1 −1
Original line number Diff line number Diff line
@@ -107,7 +107,7 @@ SCHED_FEAT(ARCH_POWER, 0) 
SCHED_FEAT(HRTICK, 0)

SCHED_FEAT(DOUBLE_TICK, 0)

SCHED_FEAT(LB_BIAS, 1)

SCHED_FEAT(LB_WAKEUP_UPDATE, 1)

SCHED_FEAT(LB_SHARES_UPDATE, 1)

SCHED_FEAT(ASYM_EFF_LOAD, 1)



/*