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authorKirill Tkhai <ktkhai@parallels.com>2014-12-15 14:56:58 +0300
committerIngo Molnar <mingo@kernel.org>2015-01-14 13:34:16 +0100
commitbb04159df99fa353d0fb524574aca03ce2c6515b (patch)
tree1ea21466b45395836fb0fd6abb6398eb012b135b /kernel/sched
parent1f8a7633094b7886c0677b78ba60b82e501f3ce6 (diff)
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 <ktkhai@parallels.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Ben Segall <bsegall@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1418644618.6074.13.camel@tkhai Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched')
-rw-r--r--kernel/sched/core.c3
-rw-r--r--kernel/sched/fair.c1
2 files changed, 3 insertions, 1 deletions
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;