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Commit de58af87 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

Revert "sched/fair: Make update_min_vruntime() more readable" 



There's a bug in this commit:

   97a7142f ("sched/fair: Make update_min_vruntime() more readable")

... when !rb_leftmost && curr we fail to advance min_vruntime.

So revert it.

Reported-by: default avatarByungchul Park <byungchul.park@lge.com>
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>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 4fa8d299

kernel/sched/fair.c

+7 −4
Original line number Diff line number Diff line
@@ -464,17 +464,20 @@ static void update_min_vruntime(struct cfs_rq *cfs_rq) 
{

	u64 vruntime = cfs_rq->min_vruntime;



	if (cfs_rq->curr)

		vruntime = cfs_rq->curr->vruntime;



	if (cfs_rq->rb_leftmost) {

		struct sched_entity *se = rb_entry(cfs_rq->rb_leftmost,

						   struct sched_entity,

						   run_node);



		if (!cfs_rq->curr)

			vruntime = se->vruntime;

		else

			vruntime = min_vruntime(vruntime, se->vruntime);

	}



	if (cfs_rq->curr)

		vruntime = min_vruntime(vruntime, cfs_rq->curr->vruntime);



	/* ensure we never gain time by being placed backwards. */

	cfs_rq->min_vruntime = max_vruntime(cfs_rq->min_vruntime, vruntime);

#ifndef CONFIG_64BIT