diff options
| author | Syed Rameez Mustafa <rameezmustafa@codeaurora.org> | 2015-07-13 11:03:02 -0700 |
|---|---|---|
| committer | David Keitel <dkeitel@codeaurora.org> | 2016-03-23 20:02:06 -0700 |
| commit | 371435451a69f4a178fbe1729c18b1820823e5c7 (patch) | |
| tree | 464bb39f5e87cc1452299ae0d6a890a18e0af75b /kernel/sched/features.h | |
| parent | c459d156283b9ca32c053ce327ece301e5821db4 (diff) | |
sched: turn off the TTWU_QUEUE feature
While the feature TTWU_QUEUE has the advantage of reducing cache
bouncing of runqueue locks, it has the side effect that runqueue
statistics are not updated until the remote CPU has a chance to
enqueue the task. Since there is no upper bound on the amount of
time it can take the remote CPU to enqueue the task, several
sequential wakeups can result in suboptimal task placement based
on the stale statistics. Turn off the feature as the cost of
sub-optimal placement is much higher than the cost of cache bouncing
spinlocks for msm based systems.
Change-Id: I0b85c0225237b2bc44f54934769f5e3750c0f3d6
Signed-off-by: Syed Rameez Mustafa <rameezmustafa@codeaurora.org>
Diffstat (limited to 'kernel/sched/features.h')
| -rw-r--r-- | kernel/sched/features.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/sched/features.h b/kernel/sched/features.h index fa71cb595e42..e1783f7952a5 100644 --- a/kernel/sched/features.h +++ b/kernel/sched/features.h @@ -49,7 +49,7 @@ SCHED_FEAT(NONTASK_CAPACITY, true) * Queue remote wakeups on the target CPU and process them * using the scheduler IPI. Reduces rq->lock contention/bounces. */ -SCHED_FEAT(TTWU_QUEUE, true) +SCHED_FEAT(TTWU_QUEUE, false) #ifdef HAVE_RT_PUSH_IPI /* |