From: Peter Zijlstra Date: Fri, 26 Jul 2013 21:48:42 +0000 (+0200) Subject: sched: Ensure update_cfs_shares() is called for parents of continuously-running tasks X-Git-Tag: v3.10.8~39 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=dead45bd0527751cc9e71c0547d8f19f498441ed;p=platform%2Fkernel%2Flinux-stable.git sched: Ensure update_cfs_shares() is called for parents of continuously-running tasks commit bf0bd948d1682e3996adc093b43021ed391983e6 upstream. We typically update a task_group's shares within the dequeue/enqueue path. However, continuously running tasks sharing a CPU are not subject to these updates as they are only put/picked. Unfortunately, when we reverted f269ae046 (in 17bc14b7), we lost the augmenting periodic update that was supposed to account for this; resulting in a potential loss of fairness. To fix this, re-introduce the explicit update in update_cfs_rq_blocked_load() [called via entity_tick()]. Reported-by: Max Hailperin Signed-off-by: Peter Zijlstra Reviewed-by: Paul Turner Link: http://lkml.kernel.org/n/tip-9545m3apw5d93ubyrotrj31y@git.kernel.org Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index c61a614..03b73be 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -1984,6 +1984,7 @@ entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr, int queued) */ update_entity_load_avg(curr, 1); update_cfs_rq_blocked_load(cfs_rq, 1); + update_cfs_shares(cfs_rq); #ifdef CONFIG_SCHED_HRTICK /*