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authorRik van Riel <riel@redhat.com>2014-05-16 00:13:32 -0400
committerIngo Molnar <mingo@kernel.org>2014-05-22 11:16:41 +0200
commit096aa33863a5e48de52d2ff30e0801b7487944f4 (patch)
treeb226a5aabe9ba4f71f192c58a2ee549ddb499871 /kernel/sched
parentb1ad065e65f56103db8b97edbd218a271ff5b1bb (diff)
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. Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: chegu_vinod@hp.com Cc: umgwanakikbuti@gmail.com Link: http://lkml.kernel.org/r/20140516001332.67f91af2@annuminas.surriel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched')
-rw-r--r--kernel/sched/fair.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 503f750c2d25..c9617b73bcc0 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;
}