2018-08-27 14:32:32 +00:00
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From: Thomas Gleixner <tglx@linutronix.de>
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Date: Tue, 13 Sep 2011 16:42:35 +0200
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2019-11-25 00:04:39 +00:00
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Subject: [PATCH 113/290] sched: Disable TTWU_QUEUE on RT
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Origin: https://git.kernel.org/cgit/linux/kernel/git/rt/linux-stable-rt.git/commit?id=f1730e401e00fbd36906e5083279d065661f685a
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2018-08-27 14:32:32 +00:00
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The queued remote wakeup mechanism can introduce rather large
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latencies if the number of migrated tasks is high. Disable it for RT.
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Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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---
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2019-04-08 23:49:20 +00:00
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kernel/sched/features.h | 5 +++++
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2018-08-27 14:32:32 +00:00
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1 file changed, 5 insertions(+)
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2019-04-08 23:49:20 +00:00
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diff --git a/kernel/sched/features.h b/kernel/sched/features.h
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index 85ae8488039c..68de18405857 100644
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2018-08-27 14:32:32 +00:00
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--- a/kernel/sched/features.h
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+++ b/kernel/sched/features.h
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@@ -46,11 +46,16 @@ SCHED_FEAT(LB_BIAS, true)
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*/
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SCHED_FEAT(NONTASK_CAPACITY, true)
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+#ifdef CONFIG_PREEMPT_RT_FULL
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+SCHED_FEAT(TTWU_QUEUE, false)
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+#else
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+
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/*
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* Queue remote wakeups on the target CPU and process them
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* using the scheduler IPI. Reduces rq->lock contention/bounces.
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*/
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SCHED_FEAT(TTWU_QUEUE, true)
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+#endif
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/*
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* When doing wakeups, attempt to limit superfluous scans of the LLC domain.
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