Commit 9b5ce1a3 authored by Mike Galbraith's avatar Mike Galbraith Committed by Peter Zijlstra
Browse files

sched: Fix sched_delayed vs cfs_bandwidth 



Meeting an unfinished DELAY_DEQUEUE treated entity in unthrottle_cfs_rq()
leads to a couple terminal scenarios.  Finish it first, so ENQUEUE_WAKEUP
can proceed as it would have sans DELAY_DEQUEUE treatment.

Fixes: 152e11f6 ("sched/fair: Implement delayed dequeue")
Reported-by: default avatarVenkat Rao Bagalkote <venkat88@linux.vnet.ibm.com>
Signed-off-by: default avatarMike Galbraith <efault@gmx.de>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: default avatarVenkat Rao Bagalkote <venkat88@linux.vnet.ibm.com>
Link: https://lore.kernel.org/r/7515d2e64c989b9e3b828a9e21bcd959b99df06a.camel@gmx.de
parent e32cde8d

kernel/sched/fair.c

+6 −3
Original line number Diff line number Diff line
@@ -6058,10 +6058,13 @@ void unthrottle_cfs_rq(struct cfs_rq *cfs_rq) 
	for_each_sched_entity(se) {

		struct cfs_rq *qcfs_rq = cfs_rq_of(se);



		if (se->on_rq) {

			SCHED_WARN_ON(se->sched_delayed);

		/* Handle any unfinished DELAY_DEQUEUE business first. */

		if (se->sched_delayed) {

			int flags = DEQUEUE_SLEEP | DEQUEUE_DELAYED;



			dequeue_entity(qcfs_rq, se, flags);

		} else if (se->on_rq)

			break;

		}

		enqueue_entity(qcfs_rq, se, ENQUEUE_WAKEUP);



		if (cfs_rq_is_idle(group_cfs_rq(se)))