The following commit has been merged into the sched/core branch of tip: Commit-ID: fc488ffd4297f661b3e9d7450dcdb9089a53df7c Gitweb: https://git.kernel.org/tip/fc488ffd4297f661b3e9d7450dcdb9089a53df7c Author: Vincent Guittot <vincent.guit...@linaro.org> AuthorDate: Thu, 07 Jan 2021 11:33:23 +01:00 Committer: Peter Zijlstra <pet...@infradead.org> CommitterDate: Thu, 14 Jan 2021 11:20:10 +01:00
sched/fair: Skip idle cfs_rq Don't waste time checking whether an idle cfs_rq could be the busiest queue. Furthermore, this can end up selecting a cfs_rq with a high load but being idle in case of migrate_load. Signed-off-by: Vincent Guittot <vincent.guit...@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Reviewed-by: Valentin Schneider <valentin.schnei...@arm.com> Acked-by: Mel Gorman <mgor...@suse.de> Link: https://lkml.kernel.org/r/20210107103325.30851-2-vincent.guit...@linaro.org --- kernel/sched/fair.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 40d3ebf..13de7ae 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -9402,8 +9402,11 @@ static struct rq *find_busiest_queue(struct lb_env *env, if (rt > env->fbq_type) continue; - capacity = capacity_of(i); nr_running = rq->cfs.h_nr_running; + if (!nr_running) + continue; + + capacity = capacity_of(i); /* * For ASYM_CPUCAPACITY domains, don't pick a CPU that could
