Messages in this thread Patch in this message | | | Date | Mon, 19 May 2014 06:11:21 -0700 | From | tip-bot for Rik van Riel <> | Subject | [tip:sched/core] sched,numa: Decay wakee_flips instead of zeroing |
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Commit-ID: 5658b4f43e63f8c7b4a27995dcb2cf43a52ee398 Gitweb: http://git.kernel.org/tip/5658b4f43e63f8c7b4a27995dcb2cf43a52ee398 Author: Rik van Riel <riel@redhat.com> AuthorDate: Fri, 16 May 2014 00:13:32 -0400 Committer: Thomas Gleixner <tglx@linutronix.de> CommitDate: Mon, 19 May 2014 22:02:43 +0900
sched,numa: Decay wakee_flips instead of zeroing
Affine wakeups have the potential to interfere with NUMA placement. If a task wakes up too many other tasks, affine wakeups will get disabled.
However, regardless of how many other tasks it wakes up, it gets re-enabled once a second, potentially interfering with NUMA placement of other tasks.
By decaying wakee_wakes in half instead of zeroing it, we can avoid that problem for some workloads.
Cc: chegu_vinod@hp.com Cc: mingo@kernel.org Cc: umgwanakikbuti@gmail.com Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20140516001332.67f91af2@annuminas.surriel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- kernel/sched/fair.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 503f750..c9617b7 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -4065,7 +4065,7 @@ static void record_wakee(struct task_struct *p) * about the loss. */ if (jiffies > current->wakee_flip_decay_ts + HZ) { - current->wakee_flips = 0; + current->wakee_flips >>= 1; current->wakee_flip_decay_ts = jiffies; }
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