49 lines
1.4 KiB
Diff
49 lines
1.4 KiB
Diff
From 155cf657f6ddcade424253eb58d03a170dc9f64f Mon Sep 17 00:00:00 2001
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From: Nicholas Mc Guire <der.herr@hofr.at>
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Date: Wed, 20 Nov 2013 07:22:09 +0800
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Subject: [PATCH 1/2] allow preemption in recursive migrate_disable call
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Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.0/patches-4.0.8-rt6.tar.xz
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Minor cleanup in migrate_disable/migrate_enable. The recursive case
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does not need to disable preemption as it is "pinned" to the current
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cpu any way so it is safe to preempt it.
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Signed-off-by: Nicholas Mc Guire <der.herr@hofr.at>
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Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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---
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kernel/sched/core.c | 6 ++----
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1 file changed, 2 insertions(+), 4 deletions(-)
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--- a/kernel/sched/core.c
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+++ b/kernel/sched/core.c
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@@ -2803,13 +2803,12 @@ void migrate_disable(void)
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WARN_ON_ONCE(p->migrate_disable_atomic);
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#endif
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- preempt_disable();
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if (p->migrate_disable) {
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p->migrate_disable++;
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- preempt_enable();
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return;
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}
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+ preempt_disable();
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pin_current_cpu();
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p->migrate_disable = 1;
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preempt_enable();
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@@ -2835,13 +2834,12 @@ void migrate_enable(void)
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#endif
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WARN_ON_ONCE(p->migrate_disable <= 0);
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- preempt_disable();
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if (migrate_disable_count(p) > 1) {
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p->migrate_disable--;
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- preempt_enable();
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return;
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}
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+ preempt_disable();
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if (unlikely(migrate_disabled_updated(p))) {
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/*
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* See comment in update_migrate_disable() about locking.
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