Commit c7b50216 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

sched/fair: Remove se->load.weight from se->avg.load_sum 



Remove the load from the load_sum for sched_entities, basically
turning load_sum into runnable_sum.  This prepares for better
reweighting of group entities.

Since we now have different rules for computing load_avg, split
___update_load_avg() into two parts, ___update_load_sum() and
___update_load_avg().

So for se:

  ___update_load_sum(.weight = 1)
  ___upate_load_avg(.weight = se->load.weight)

and for cfs_rq:

  ___update_load_sum(.weight = cfs_rq->load.weight)
  ___upate_load_avg(.weight = 1)

Since the primary consumable is load_avg, most things will not be
affected. Only those few sites that initialize/modify load_sum need
attention.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 3d4b60d3

kernel/sched/fair.c

+64 −27
Original line number Diff line number Diff line
@@ -731,7 +731,7 @@ void init_entity_runnable_average(struct sched_entity *se) 
	 */

	if (entity_is_task(se))

		sa->load_avg = scale_load_down(se->load.weight);

	sa->load_sum = sa->load_avg * LOAD_AVG_MAX;

	sa->load_sum = LOAD_AVG_MAX;

	/*

	 * At this point, util_avg won't be used in select_task_rq_fair anyway

	 */
@@ -2025,7 +2025,7 @@ static u64 numa_get_avg_runtime(struct task_struct *p, u64 *period) 
		delta = runtime - p->last_sum_exec_runtime;

		*period = now - p->last_task_numa_placement;

	} else {

		delta = p->se.avg.load_sum / p->se.load.weight;

		delta = p->se.avg.load_sum;

		*period = LOAD_AVG_MAX;

	}
@@ -3018,7 +3018,7 @@ accumulate_sum(u64 delta, int cpu, struct sched_avg *sa, 
 *            = u_0 + u_1*y + u_2*y^2 + ... [re-labeling u_i --> u_{i+1}]

 */

static __always_inline int

___update_load_avg(u64 now, int cpu, struct sched_avg *sa,

___update_load_sum(u64 now, int cpu, struct sched_avg *sa,

		   unsigned long weight, int running, struct cfs_rq *cfs_rq)

{

	u64 delta;
@@ -3065,39 +3065,80 @@ ___update_load_avg(u64 now, int cpu, struct sched_avg *sa, 
	if (!accumulate_sum(delta, cpu, sa, weight, running, cfs_rq))

		return 0;



	return 1;

}



static __always_inline void

___update_load_avg(struct sched_avg *sa, unsigned long weight, struct cfs_rq *cfs_rq)

{

	u32 divider = LOAD_AVG_MAX - 1024 + sa->period_contrib;



	/*

	 * Step 2: update *_avg.

	 */

	sa->load_avg = div_u64(sa->load_sum, LOAD_AVG_MAX - 1024 + sa->period_contrib);

	sa->load_avg = div_u64(weight * sa->load_sum, divider);

	if (cfs_rq) {

		cfs_rq->runnable_load_avg =

			div_u64(cfs_rq->runnable_load_sum, LOAD_AVG_MAX - 1024 + sa->period_contrib);

			div_u64(cfs_rq->runnable_load_sum, divider);

	}

	sa->util_avg = sa->util_sum / divider;

}

	sa->util_avg = sa->util_sum / (LOAD_AVG_MAX - 1024 + sa->period_contrib);



	return 1;

/*

 * XXX we want to get rid of this helper and use the full load resolution.

 */

static inline long se_weight(struct sched_entity *se)

{

	return scale_load_down(se->load.weight);

}



/*

 * sched_entity:

 *

 *   load_sum := runnable_sum

 *   load_avg = se_weight(se) * runnable_avg

 *

 * cfq_rs:

 *

 *   load_sum = \Sum se_weight(se) * se->avg.load_sum

 *   load_avg = \Sum se->avg.load_avg

 */



static int

__update_load_avg_blocked_se(u64 now, int cpu, struct sched_entity *se)

{

	return ___update_load_avg(now, cpu, &se->avg, 0, 0, NULL);

	if (___update_load_sum(now, cpu, &se->avg, 0, 0, NULL)) {

		___update_load_avg(&se->avg, se_weight(se), NULL);

		return 1;

	}



	return 0;

}



static int

__update_load_avg_se(u64 now, int cpu, struct cfs_rq *cfs_rq, struct sched_entity *se)

{

	return ___update_load_avg(now, cpu, &se->avg,

				  se->on_rq * scale_load_down(se->load.weight),

				  cfs_rq->curr == se, NULL);

	if (___update_load_sum(now, cpu, &se->avg, !!se->on_rq,

				cfs_rq->curr == se, NULL)) {



		___update_load_avg(&se->avg, se_weight(se), NULL);

		return 1;

	}



	return 0;

}



static int

__update_load_avg_cfs_rq(u64 now, int cpu, struct cfs_rq *cfs_rq)

{

	return ___update_load_avg(now, cpu, &cfs_rq->avg,

	if (___update_load_sum(now, cpu, &cfs_rq->avg,

				scale_load_down(cfs_rq->load.weight),

			cfs_rq->curr != NULL, cfs_rq);

				cfs_rq->curr != NULL, cfs_rq)) {

		___update_load_avg(&cfs_rq->avg, 1, cfs_rq);

		return 1;

	}



	return 0;

}



/*
@@ -3267,7 +3308,7 @@ update_tg_cfs_load(struct cfs_rq *cfs_rq, struct sched_entity *se) 


	/* Set new sched_entity's load */

	se->avg.load_avg = load;

	se->avg.load_sum = se->avg.load_avg * LOAD_AVG_MAX;

	se->avg.load_sum = LOAD_AVG_MAX;



	/* Update parent cfs_rq load */

	add_positive(&cfs_rq->avg.load_avg, delta);
@@ -3473,7 +3514,7 @@ static void attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *s 
{

	se->avg.last_update_time = cfs_rq->avg.last_update_time;

	cfs_rq->avg.load_avg += se->avg.load_avg;

	cfs_rq->avg.load_sum += se->avg.load_sum;

	cfs_rq->avg.load_sum += se_weight(se) * se->avg.load_sum;

	cfs_rq->avg.util_avg += se->avg.util_avg;

	cfs_rq->avg.util_sum += se->avg.util_sum;

	set_tg_cfs_propagate(cfs_rq);
@@ -3493,7 +3534,7 @@ static void detach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *s 
{



	sub_positive(&cfs_rq->avg.load_avg, se->avg.load_avg);

	sub_positive(&cfs_rq->avg.load_sum, se->avg.load_sum);

	sub_positive(&cfs_rq->avg.load_sum, se_weight(se) * se->avg.load_sum);

	sub_positive(&cfs_rq->avg.util_avg, se->avg.util_avg);

	sub_positive(&cfs_rq->avg.util_sum, se->avg.util_sum);

	set_tg_cfs_propagate(cfs_rq);
@@ -3505,12 +3546,10 @@ static void detach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *s 
static inline void

enqueue_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se)

{

	struct sched_avg *sa = &se->avg;



	cfs_rq->runnable_load_avg += sa->load_avg;

	cfs_rq->runnable_load_sum += sa->load_sum;

	cfs_rq->runnable_load_avg += se->avg.load_avg;

	cfs_rq->runnable_load_sum += se_weight(se) * se->avg.load_sum;



	if (!sa->last_update_time) {

	if (!se->avg.last_update_time) {

		attach_entity_load_avg(cfs_rq, se);

		update_tg_load_avg(cfs_rq, 0);

	}
@@ -3520,10 +3559,8 @@ enqueue_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) 
static inline void

dequeue_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se)

{

	cfs_rq->runnable_load_avg =

		max_t(long, cfs_rq->runnable_load_avg - se->avg.load_avg, 0);

	cfs_rq->runnable_load_sum =

		max_t(s64,  cfs_rq->runnable_load_sum - se->avg.load_sum, 0);

	sub_positive(&cfs_rq->runnable_load_avg, se->avg.load_avg);

	sub_positive(&cfs_rq->runnable_load_sum, se_weight(se) * se->avg.load_sum);

}



#ifndef CONFIG_64BIT

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