| From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> |
| Date: Wed 02 Dec 2015 11:34:07 +0100 |
| Subject: rtmutex: trylock is okay on -RT |
| |
| non-RT kernel could deadlock on rt_mutex_trylock() in softirq context. On |
| -RT we don't run softirqs in IRQ context but in thread context so it is |
| not a issue here. |
| |
| Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> |
| --- |
| kernel/locking/rtmutex.c | 4 ++++ |
| 1 file changed, 4 insertions(+) |
| |
| --- a/kernel/locking/rtmutex.c |
| +++ b/kernel/locking/rtmutex.c |
| @@ -1547,7 +1547,11 @@ EXPORT_SYMBOL_GPL(rt_mutex_timed_lock); |
| */ |
| int __sched rt_mutex_trylock(struct rt_mutex *lock) |
| { |
| +#ifdef CONFIG_PREEMPT_RT_FULL |
| + if (WARN_ON_ONCE(in_irq() || in_nmi())) |
| +#else |
| if (WARN_ON_ONCE(in_irq() || in_nmi() || in_serving_softirq())) |
| +#endif |
| return 0; |
| |
| return rt_mutex_fasttrylock(lock, rt_mutex_slowtrylock); |
