88 lines
2.8 KiB
Diff
88 lines
2.8 KiB
Diff
From 4602d705c8d62807ab76a3eedc71fd9e944ca0b3 Mon Sep 17 00:00:00 2001
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From: Thomas Gleixner <tglx@linutronix.de>
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Date: Sun, 15 Nov 2015 18:40:17 +0100
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Subject: [PATCH 243/365] irqwork: Move irq safe work to irq context
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On architectures where arch_irq_work_has_interrupt() returns false, we
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end up running the irq safe work from the softirq context. That
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results in a potential deadlock in the scheduler irq work which
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expects that function to be called with interrupts disabled.
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Split the irq_work_tick() function into a hard and soft variant. Call
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the hard variant from the tick interrupt and add the soft variant to
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the timer softirq.
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Reported-and-tested-by: Yanjiang Jin <yanjiang.jin@windriver.com>
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Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Cc: stable-rt@vger.kernel.org
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---
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include/linux/irq_work.h | 6 ++++++
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kernel/irq_work.c | 9 +++++++++
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kernel/time/timer.c | 6 ++----
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3 files changed, 17 insertions(+), 4 deletions(-)
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diff --git a/include/linux/irq_work.h b/include/linux/irq_work.h
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index 0e427a9997f3..2543aab05daa 100644
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--- a/include/linux/irq_work.h
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+++ b/include/linux/irq_work.h
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@@ -52,4 +52,10 @@ static inline bool irq_work_needs_cpu(void) { return false; }
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static inline void irq_work_run(void) { }
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#endif
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+#if defined(CONFIG_IRQ_WORK) && defined(CONFIG_PREEMPT_RT_FULL)
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+void irq_work_tick_soft(void);
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+#else
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+static inline void irq_work_tick_soft(void) { }
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+#endif
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+
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#endif /* _LINUX_IRQ_WORK_H */
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diff --git a/kernel/irq_work.c b/kernel/irq_work.c
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index 0ddaf1e66d8c..2899ba0d23d1 100644
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--- a/kernel/irq_work.c
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+++ b/kernel/irq_work.c
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@@ -200,8 +200,17 @@ void irq_work_tick(void)
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if (!llist_empty(raised) && !arch_irq_work_has_interrupt())
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irq_work_run_list(raised);
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+
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+ if (!IS_ENABLED(CONFIG_PREEMPT_RT_FULL))
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+ irq_work_run_list(this_cpu_ptr(&lazy_list));
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+}
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+
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+#if defined(CONFIG_IRQ_WORK) && defined(CONFIG_PREEMPT_RT_FULL)
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+void irq_work_tick_soft(void)
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+{
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irq_work_run_list(this_cpu_ptr(&lazy_list));
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}
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+#endif
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/*
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* Synchronize against the irq_work @entry, ensures the entry is not
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diff --git a/kernel/time/timer.c b/kernel/time/timer.c
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index b742e84cbe1c..af9d338103a9 100644
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--- a/kernel/time/timer.c
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+++ b/kernel/time/timer.c
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@@ -1664,7 +1664,7 @@ void update_process_times(int user_tick)
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scheduler_tick();
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run_local_timers();
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rcu_check_callbacks(user_tick);
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-#if defined(CONFIG_IRQ_WORK) && !defined(CONFIG_PREEMPT_RT_FULL)
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+#if defined(CONFIG_IRQ_WORK)
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if (in_irq())
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irq_work_tick();
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#endif
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@@ -1720,9 +1720,7 @@ static __latent_entropy void run_timer_softirq(struct softirq_action *h)
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{
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struct timer_base *base = this_cpu_ptr(&timer_bases[BASE_STD]);
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-#if defined(CONFIG_IRQ_WORK) && defined(CONFIG_PREEMPT_RT_FULL)
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- irq_work_tick();
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-#endif
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+ irq_work_tick_soft();
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__run_timers(base);
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if (IS_ENABLED(CONFIG_NO_HZ_COMMON))
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--
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2.28.0
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