Commit 9437178f authored by Paul Turner's avatar Paul Turner Committed by Ingo Molnar
Browse files

sched: Update tg->shares after cpu.shares write 



Formerly sched_group_set_shares would force a rebalance by overflowing domain
share sums.  Now that per-cpu averages are maintained we can set the true value
by issuing an update_cfs_shares() following a tg->shares update.

Also initialize tg se->load to 0 for consistency since we'll now set correct
weights on enqueue.

Signed-off-by: default avatarPaul Turner <pjt@google.com?>
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101115234938.465521344@google.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent d6b55918

kernel/sched.c

+11 −31
Original line number Diff line number Diff line
@@ -7646,7 +7646,7 @@ static void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq, 
		se->cfs_rq = parent->my_q;



	se->my_q = cfs_rq;

	update_load_set(&se->load, tg->shares);

	update_load_set(&se->load, 0);

	se->parent = parent;

}

#endif
@@ -8274,37 +8274,12 @@ void sched_move_task(struct task_struct *tsk) 
#endif /* CONFIG_CGROUP_SCHED */



#ifdef CONFIG_FAIR_GROUP_SCHED

static void __set_se_shares(struct sched_entity *se, unsigned long shares)

{

	struct cfs_rq *cfs_rq = se->cfs_rq;

	int on_rq;



	on_rq = se->on_rq;

	if (on_rq)

		dequeue_entity(cfs_rq, se, 0);



	update_load_set(&se->load, shares);



	if (on_rq)

		enqueue_entity(cfs_rq, se, 0);

}



static void set_se_shares(struct sched_entity *se, unsigned long shares)

{

	struct cfs_rq *cfs_rq = se->cfs_rq;

	struct rq *rq = cfs_rq->rq;

	unsigned long flags;



	raw_spin_lock_irqsave(&rq->lock, flags);

	__set_se_shares(se, shares);

	raw_spin_unlock_irqrestore(&rq->lock, flags);

}



static DEFINE_MUTEX(shares_mutex);



int sched_group_set_shares(struct task_group *tg, unsigned long shares)

{

	int i;

	unsigned long flags;



	/*

	 * We can't change the weight of the root cgroup.
@@ -8323,10 +8298,15 @@ int sched_group_set_shares(struct task_group *tg, unsigned long shares) 


	tg->shares = shares;

	for_each_possible_cpu(i) {

		/*

		 * force a rebalance

		 */

		set_se_shares(tg->se[i], shares);

		struct rq *rq = cpu_rq(i);

		struct sched_entity *se;



		se = tg->se[i];

		/* Propagate contribution to hierarchy */

		raw_spin_lock_irqsave(&rq->lock, flags);

		for_each_sched_entity(se)

			update_cfs_shares(group_cfs_rq(se), 0);

		raw_spin_unlock_irqrestore(&rq->lock, flags);

	}



done:

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