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authorByungchul Park <byungchul.park@lge.com>2015-10-23 19:16:19 +0300
committerIngo Molnar <mingo@kernel.org>2015-12-04 12:34:42 +0300
commitad936d8658fd348338cb7d42c577dac77892b074 (patch)
tree0ba206f9c8515b4ed01b132d885f9bf07715b937 /kernel/sched/core.c
parent467386fbbf085e716570813a5d3be3927c348e11 (diff)
downloadlinux-ad936d8658fd348338cb7d42c577dac77892b074.tar.xz
sched/fair: Make it possible to account fair load avg consistently
The current code accounts for the time a task was absent from the fair class (per ATTACH_AGE_LOAD). However it does not work correctly when a task got migrated or moved to another cgroup while outside of the fair class. This patch tries to address that by aging on migration. We locklessly read the 'last_update_time' stamp from both the old and new cfs_rq, ages the load upto the old time, and sets it to the new time. These timestamps should in general not be more than 1 tick apart from one another, so there is a definite bound on things. Signed-off-by: Byungchul Park <byungchul.park@lge.com> [ Changelog, a few edits and !SMP build fix ] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1445616981-29904-2-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched/core.c')
-rw-r--r--kernel/sched/core.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 8969a9a9dab5..32d83e49cfd7 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2120,6 +2120,10 @@ static void __sched_fork(unsigned long clone_flags, struct task_struct *p)
p->se.vruntime = 0;
INIT_LIST_HEAD(&p->se.group_node);
+#ifdef CONFIG_FAIR_GROUP_SCHED
+ p->se.cfs_rq = NULL;
+#endif
+
#ifdef CONFIG_SCHEDSTATS
memset(&p->se.statistics, 0, sizeof(p->se.statistics));
#endif