Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit ebc28671 authored by Leo Yan's avatar Leo Yan Committed by Chris Redpath
Browse files

sched/fair: kick nohz idle balance for misfit task 

If there have misfit task on one CPU, current code does not handle this
situation for nohz idle balance. As result, we can see the misfit task
stays run on little core for long time.

So this patch check if the CPU has misfit task or not. If has misfit
task then kick nohz idle balance so finally can execute active balance.

Change-Id: I117d3b7404296f8de11cb960a87a6b9a54a9f348
Signed-off-by: Leo Yan <leo.yan at linaro.org>
[taken from https://lists.linaro.org/pipermail/eas-dev/2016-September/000551.html

]
Signed-off-by: default avatarChris Redpath <chris.redpath@arm.com>
Signed-off-by: default avatarPatrick Bellasi <patrick.bellasi@arm.com>
parent 7b63e1ff

kernel/sched/fair.c

+4 −0
Original line number Diff line number Diff line
@@ -9701,6 +9701,10 @@ static inline bool nohz_kick_needed(struct rq *rq) 
	    (!energy_aware() || cpu_overutilized(cpu)))

		return true;



	/* Do idle load balance if there have misfit task */

	if (energy_aware() && rq->misfit_task)

		return true;



	rcu_read_lock();

	sd = rcu_dereference(per_cpu(sd_busy, cpu));

	if (sd && !energy_aware()) {