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Commit 8165e145 authored by Paul Turner's avatar Paul Turner Committed by Ingo Molnar
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sched: Compute load contribution by a group entity 



Unlike task entities who have a fixed weight, group entities instead own a
fraction of their parenting task_group's shares as their contributed weight.

Compute this fraction so that we can correctly account hierarchies and shared
entity nodes.

Signed-off-by: default avatarPaul Turner <pjt@google.com>
Reviewed-by: default avatarBen Segall <bsegall@google.com>
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20120823141506.855074415@google.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent c566e8e9

kernel/sched/fair.c

+27 −6
Original line number Diff line number Diff line
@@ -1117,22 +1117,43 @@ static inline void __update_cfs_rq_tg_load_contrib(struct cfs_rq *cfs_rq, 
		cfs_rq->tg_load_contrib += tg_contrib;

	}

}



static inline void __update_group_entity_contrib(struct sched_entity *se)

{

	struct cfs_rq *cfs_rq = group_cfs_rq(se);

	struct task_group *tg = cfs_rq->tg;

	u64 contrib;



	contrib = cfs_rq->tg_load_contrib * tg->shares;

	se->avg.load_avg_contrib = div64_u64(contrib,

					     atomic64_read(&tg->load_avg) + 1);

}

#else

static inline void __update_cfs_rq_tg_load_contrib(struct cfs_rq *cfs_rq,

						 int force_update) {}

static inline void __update_group_entity_contrib(struct sched_entity *se) {}

#endif



static inline void __update_task_entity_contrib(struct sched_entity *se)

{

	u32 contrib;



	/* avoid overflowing a 32-bit type w/ SCHED_LOAD_SCALE */

	contrib = se->avg.runnable_avg_sum * scale_load_down(se->load.weight);

	contrib /= (se->avg.runnable_avg_period + 1);

	se->avg.load_avg_contrib = scale_load(contrib);

}



/* Compute the current contribution to load_avg by se, return any delta */

static long __update_entity_load_avg_contrib(struct sched_entity *se)

{

	long old_contrib = se->avg.load_avg_contrib;



	if (!entity_is_task(se))

		return 0;



	se->avg.load_avg_contrib = div64_u64(se->avg.runnable_avg_sum *

					     se->load.weight,

					     se->avg.runnable_avg_period + 1);

	if (entity_is_task(se)) {

		__update_task_entity_contrib(se);

	} else {

		__update_group_entity_contrib(se);

	}



	return se->avg.load_avg_contrib - old_contrib;

}