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| author | Thomas Gleixner <tglx@linutronix.de> | 2015-11-15 18:40:17 +0100 |
|---|---|---|
| committer | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2016-02-13 00:36:24 +0100 |
| commit | 3382a172b546cea7778e0c937f6786af1735b147 (patch) | |
| tree | b288f784a13e9f220a1e39f1bc7d3a16fbe778fa | |
| parent | 93b0cba2ec75deff1b3a664d2fac9ad8b8292d8f (diff) | |
| download | rt-linux-3382a172b546cea7778e0c937f6786af1735b147.tar.gz | |
irqwork: Move irq safe work to irq context
On architectures where arch_irq_work_has_interrupt() returns false, we
end up running the irq safe work from the softirq context. That
results in a potential deadlock in the scheduler irq work which
expects that function to be called with interrupts disabled.
Split the irq_work_tick() function into a hard and soft variant. Call
the hard variant from the tick interrupt and add the soft variant to
the timer softirq.
Reported-and-tested-by: Yanjiang Jin <yanjiang.jin@windriver.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable-rt@vger.kernel.org
| -rw-r--r-- | include/linux/irq_work.h | 6 | ||||
| -rw-r--r-- | kernel/irq_work.c | 9 | ||||
| -rw-r--r-- | kernel/time/timer.c | 6 |
3 files changed, 17 insertions, 4 deletions
diff --git a/include/linux/irq_work.h b/include/linux/irq_work.h index 0e427a9997f3bd..2543aab05daa05 100644 --- a/include/linux/irq_work.h +++ b/include/linux/irq_work.h @@ -52,4 +52,10 @@ static inline bool irq_work_needs_cpu(void) { return false; } static inline void irq_work_run(void) { } #endif +#if defined(CONFIG_IRQ_WORK) && defined(CONFIG_PREEMPT_RT_FULL) +void irq_work_tick_soft(void); +#else +static inline void irq_work_tick_soft(void) { } +#endif + #endif /* _LINUX_IRQ_WORK_H */ diff --git a/kernel/irq_work.c b/kernel/irq_work.c index 0ddaf1e66d8c92..2899ba0d23d175 100644 --- a/kernel/irq_work.c +++ b/kernel/irq_work.c @@ -200,8 +200,17 @@ void irq_work_tick(void) if (!llist_empty(raised) && !arch_irq_work_has_interrupt()) irq_work_run_list(raised); + + if (!IS_ENABLED(CONFIG_PREEMPT_RT_FULL)) + irq_work_run_list(this_cpu_ptr(&lazy_list)); +} + +#if defined(CONFIG_IRQ_WORK) && defined(CONFIG_PREEMPT_RT_FULL) +void irq_work_tick_soft(void) +{ irq_work_run_list(this_cpu_ptr(&lazy_list)); } +#endif /* * Synchronize against the irq_work @entry, ensures the entry is not diff --git a/kernel/time/timer.c b/kernel/time/timer.c index 606580f85ac568..fee8682c209e3f 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -1484,7 +1484,7 @@ void update_process_times(int user_tick) scheduler_tick(); run_local_timers(); rcu_check_callbacks(user_tick); -#if defined(CONFIG_IRQ_WORK) && !defined(CONFIG_PREEMPT_RT_FULL) +#if defined(CONFIG_IRQ_WORK) if (in_irq()) irq_work_tick(); #endif @@ -1498,9 +1498,7 @@ static void run_timer_softirq(struct softirq_action *h) { struct tvec_base *base = this_cpu_ptr(&tvec_bases); -#if defined(CONFIG_IRQ_WORK) && defined(CONFIG_PREEMPT_RT_FULL) - irq_work_tick(); -#endif + irq_work_tick_soft(); if (time_after_eq(jiffies, base->timer_jiffies)) __run_timers(base); |