From: Byungchul Park <[email protected]> change from v2 to v3 * rebase to tip git
change from v1 to v2 * use #ifdef CONFIG_SMP to load tracking code * make commit message compact which made confused ----->8----- >From 31c4509d09cd43bf52c12ef85716aa4c3b729b57 Mon Sep 17 00:00:00 2001 From: Byungchul Park <[email protected]> Date: Wed, 12 Aug 2015 15:51:21 +0900 Subject: [PATCH v3] sched: sync with the prev cfs when changing cgroup within a cpu current code seems to be wrong with cfs_rq's avg loads when changing a task's cgroup(=cfs_rq) to another. i tested with "echo pid > cgroup" and found that e.g. cfs_rq->avg.load_avg became larger and larger whenever i changed a cgroup to another again and again. we have to sync se's average load with both *prev* cfs_rq and next cfs_rq when changing its group. Signed-off-by: Byungchul Park <[email protected]> --- kernel/sched/fair.c | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 2a33d7b..25028b9 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -8017,8 +8017,28 @@ static void task_move_group_fair(struct task_struct *p, int queued) if (!queued && (!se->sum_exec_runtime || p->state == TASK_WAKING)) queued = 1; - if (!queued) - se->vruntime -= cfs_rq_of(se)->min_vruntime; + if (!queued) { + cfs_rq = cfs_rq_of(se); + se->vruntime -= cfs_rq->min_vruntime; + +#ifdef CONFIG_SMP + /* + * synchronize task with its prev cfs_rq + * remove our load when we leave + */ + __update_load_avg(cfs_rq->avg.last_update_time, cpu_of(rq_of(cfs_rq)), &se->avg, + se->on_rq * scale_load_down(se->load.weight), cfs_rq->curr == se, NULL); + + cfs_rq->avg.load_avg = + max_t(long, cfs_rq->avg.load_avg - se->avg.load_avg, 0); + cfs_rq->avg.load_sum = + max_t(s64, cfs_rq->avg.load_sum - se->avg.load_sum, 0); + cfs_rq->avg.util_avg = + max_t(long, cfs_rq->avg.util_avg - se->avg.util_avg, 0); + cfs_rq->avg.util_sum = + max_t(s32, cfs_rq->avg.util_sum - se->avg.util_sum, 0); +#endif + } set_task_rq(p, task_cpu(p)); se->depth = se->parent ? se->parent->depth + 1 : 0; if (!queued) { -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
