Commit-ID: 8ed92e51f99c2199c64cb33b4ba95ab12940a94c Gitweb: http://git.kernel.org/tip/8ed92e51f99c2199c64cb33b4ba95ab12940a94c Author: Ingo Molnar <mingo@xxxxxxx> AuthorDate: Sun, 14 Oct 2012 14:28:50 +0200 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Tue, 16 Oct 2012 10:05:27 +0200 sched: Add WAKEUP_PREEMPTION feature flag, on by default As per the recent discussion with Mike and Linus, make it easier to test with/without this feature. No change in default behavior. Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> Cc: Mike Galbraith <efault@xxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Link: http://lkml.kernel.org/n/tip-izoxq4haeg4mTognnDbwcevt@xxxxxxxxxxxxxx --- kernel/sched/fair.c | 2 +- kernel/sched/features.h | 5 +++++ 2 files changed, 6 insertions(+), 1 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 6b800a1..f936552 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -2907,7 +2907,7 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_ * Batch and idle tasks do not preempt non-idle tasks (their preemption * is driven by the tick): */ - if (unlikely(p->policy != SCHED_NORMAL)) + if (unlikely(p->policy != SCHED_NORMAL) || !sched_feat(WAKEUP_PREEMPTION)) return; find_matching_se(&se, &pse); diff --git a/kernel/sched/features.h b/kernel/sched/features.h index eebefca..e68e69a 100644 --- a/kernel/sched/features.h +++ b/kernel/sched/features.h @@ -32,6 +32,11 @@ SCHED_FEAT(LAST_BUDDY, true) SCHED_FEAT(CACHE_HOT_BUDDY, true) /* + * Allow wakeup-time preemption of the current task: + */ +SCHED_FEAT(WAKEUP_PREEMPTION, true) + +/* * Use arch dependent cpu power functions */ SCHED_FEAT(ARCH_POWER, true) -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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