33 lines
960 B
Diff
33 lines
960 B
Diff
Subject: sched: Disable TTWU_QUEUE on RT
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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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Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.25-rt16.tar.xz
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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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kernel/sched/features.h | 5 +++++
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1 file changed, 5 insertions(+)
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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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