81 lines
2.4 KiB
Diff
81 lines
2.4 KiB
Diff
From: Mike Galbraith <efault@gmx.de>
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Date: Fri, 20 Jan 2017 18:10:20 +0100
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Subject: [PATCH] softirq: wake the timer softirq if needed
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Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.14/older/patches-4.14-rt1.tar.xz
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The irq-exit path only checks the "normal"-softirq thread if it is
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running and ignores the state of the "timer"-softirq thread. It is possible
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that the timer-softirq thread is and has work pending which leads to the
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following warning:
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[ 84.087571] NOHZ: local_softirq_pending 02
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[ 84.087593] NOHZ: local_softirq_pending 02
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[ 84.087598] NOHZ: local_softirq_pending 02
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[ 84.087904] NOHZ: local_softirq_pending 02
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[ 84.088526] NOHZ: local_softirq_pending 02
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[ 84.088899] NOHZ: local_softirq_pending 02
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[ 84.089463] NOHZ: local_softirq_pending 02
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[ 115.013470] NOHZ: local_softirq_pending 02
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[ 115.013601] NOHZ: local_softirq_pending 02
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[ 115.013709] NOHZ: local_softirq_pending 02
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This was introduced during the timer-softirq split.
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Cc: stable-rt@vger.kernel.org
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Signed-off-by: Mike Galbraith <efault@gmx.de>
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Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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---
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kernel/softirq.c | 11 +++++------
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1 file changed, 5 insertions(+), 6 deletions(-)
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--- a/kernel/softirq.c
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+++ b/kernel/softirq.c
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@@ -28,6 +28,7 @@
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#include <linux/tick.h>
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#include <linux/locallock.h>
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#include <linux/irq.h>
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+#include <linux/sched/types.h>
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#define CREATE_TRACE_POINTS
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#include <trace/events/irq.h>
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@@ -206,6 +207,7 @@ static void handle_softirq(unsigned int
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}
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}
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+#ifndef CONFIG_PREEMPT_RT_FULL
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/*
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* If ksoftirqd is scheduled, we do not want to process pending softirqs
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* right now. Let ksoftirqd handle this at its own rate, to get fairness.
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@@ -217,7 +219,6 @@ static bool ksoftirqd_running(void)
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return tsk && (tsk->state == TASK_RUNNING);
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}
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-#ifndef CONFIG_PREEMPT_RT_FULL
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static inline int ksoftirqd_softirq_pending(void)
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{
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return local_softirq_pending();
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@@ -773,13 +774,10 @@ void irq_enter(void)
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static inline void invoke_softirq(void)
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{
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-#ifdef CONFIG_PREEMPT_RT_FULL
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- unsigned long flags;
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-#endif
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-
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+#ifndef CONFIG_PREEMPT_RT_FULL
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if (ksoftirqd_running())
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return;
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-#ifndef CONFIG_PREEMPT_RT_FULL
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+
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if (!force_irqthreads) {
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#ifdef CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK
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/*
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@@ -800,6 +798,7 @@ static inline void invoke_softirq(void)
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wakeup_softirqd();
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}
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#else /* PREEMPT_RT_FULL */
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+ unsigned long flags;
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local_irq_save(flags);
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if (__this_cpu_read(ksoftirqd) &&
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