From bb04159df99fa353d0fb524574aca03ce2c6515b Mon Sep 17 00:00:00 2001 From: Kirill Tkhai Date: Mon, 15 Dec 2014 14:56:58 +0300 Subject: [PATCH] sched/fair: Fix sched_entity::avg::decay_count initialization Child has the same decay_count as parent. If it's not zero, we add it to parent's cfs_rq->removed_load: wake_up_new_task()->set_task_cpu()->migrate_task_rq_fair(). Child's load is a just garbade after copying of parent, it hasn't been on cfs_rq yet, and it must not be added to cfs_rq::removed_load in migrate_task_rq_fair(). The patch moves sched_entity::avg::decay_count intialization in sched_fork(). So, migrate_task_rq_fair() does not change removed_load. Signed-off-by: Kirill Tkhai Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Ben Segall Cc: Linus Torvalds Link: http://lkml.kernel.org/r/1418644618.6074.13.camel@tkhai Signed-off-by: Ingo Molnar --- kernel/sched/core.c | 3 +++ kernel/sched/fair.c | 1 - 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 816c17203c16..95ac795ab3d3 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1832,6 +1832,9 @@ static void __sched_fork(unsigned long clone_flags, struct task_struct *p) p->se.prev_sum_exec_runtime = 0; p->se.nr_migrations = 0; p->se.vruntime = 0; +#ifdef CONFIG_SMP + p->se.avg.decay_count = 0; +#endif INIT_LIST_HEAD(&p->se.group_node); #ifdef CONFIG_SCHEDSTATS diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 97000a99a293..2a0b302e51de 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -676,7 +676,6 @@ void init_task_runnable_average(struct task_struct *p) { u32 slice; - p->se.avg.decay_count = 0; slice = sched_slice(task_cfs_rq(p), &p->se) >> 10; p->se.avg.runnable_avg_sum = slice; p->se.avg.runnable_avg_period = slice; -- 2.20.1