Commit 810b3817 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

sched: retain vruntime 



Kei Tokunaga reported an interactivity problem when moving tasks
between control groups.

Tasks would retain their old vruntime when moved between groups, this
can cause funny lags. Re-set the vruntime on group move to fit within
the new tree.

Reported-by: default avatarKei Tokunaga <tokunaga.keiich@jp.fujitsu.com>
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent ce4796d1

include/linux/sched.h

+4 −0
Original line number Diff line number Diff line
@@ -899,6 +899,10 @@ struct sched_class { 
			     int running);

	void (*prio_changed) (struct rq *this_rq, struct task_struct *task,

			     int oldprio, int running);



#ifdef CONFIG_FAIR_GROUP_SCHED

	void (*moved_group) (struct task_struct *p);

#endif

};



struct load_weight {

kernel/sched.c

+5 −0
Original line number Diff line number Diff line
@@ -7625,6 +7625,11 @@ void sched_move_task(struct task_struct *tsk) 


	set_task_rq(tsk, task_cpu(tsk));



#ifdef CONFIG_FAIR_GROUP_SCHED

	if (tsk->sched_class->moved_group)

		tsk->sched_class->moved_group(tsk);

#endif



	if (on_rq) {

		if (unlikely(running))

			tsk->sched_class->set_curr_task(rq);

kernel/sched_fair.c

+14 −0
Original line number Diff line number Diff line
@@ -1353,6 +1353,16 @@ static void set_curr_task_fair(struct rq *rq) 
		set_next_entity(cfs_rq_of(se), se);

}



#ifdef CONFIG_FAIR_GROUP_SCHED

static void moved_group_fair(struct task_struct *p)

{

	struct cfs_rq *cfs_rq = task_cfs_rq(p);



	update_curr(cfs_rq);

	place_entity(cfs_rq, &p->se, 1);

}

#endif



/*

 * All the scheduling class methods:

 */
@@ -1381,6 +1391,10 @@ static const struct sched_class fair_sched_class = { 


	.prio_changed		= prio_changed_fair,

	.switched_to		= switched_to_fair,



#ifdef CONFIG_FAIR_GROUP_SCHED

	.moved_group		= moved_group_fair,

#endif

};



#ifdef CONFIG_SCHED_DEBUG

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