diff options
| -rw-r--r-- | include/linux/timer.h | 4 | ||||
| -rw-r--r-- | kernel/timer.c | 53 |
2 files changed, 36 insertions, 21 deletions
diff --git a/include/linux/timer.h b/include/linux/timer.h index 2e78fedfc069..221f81ac2002 100644 --- a/include/linux/timer.h +++ b/include/linux/timer.h @@ -76,9 +76,11 @@ static inline void add_timer(struct timer_list * timer) } #ifdef CONFIG_SMP + extern int try_to_del_timer_sync(struct timer_list *timer); extern int del_timer_sync(struct timer_list *timer); #else -# define del_timer_sync(t) del_timer(t) +# define try_to_del_timer_sync(t) del_timer(t) +# define del_timer_sync(t) del_timer(t) #endif #define del_singleshot_timer_sync(t) del_timer_sync(t) diff --git a/kernel/timer.c b/kernel/timer.c index 8aadc62efd65..1f986c16d89f 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -365,6 +365,34 @@ int del_timer(struct timer_list *timer) EXPORT_SYMBOL(del_timer); #ifdef CONFIG_SMP +/* + * This function tries to deactivate a timer. Upon successful (ret >= 0) + * exit the timer is not queued and the handler is not running on any CPU. + * + * It must not be called from interrupt contexts. + */ +int try_to_del_timer_sync(struct timer_list *timer) +{ + timer_base_t *base; + unsigned long flags; + int ret = -1; + + base = lock_timer_base(timer, &flags); + + if (base->running_timer == timer) + goto out; + + ret = 0; + if (timer_pending(timer)) { + detach_timer(timer, 1); + ret = 1; + } +out: + spin_unlock_irqrestore(&base->lock, flags); + + return ret; +} + /*** * del_timer_sync - deactivate a timer and wait for the handler to finish. * @timer: the timer to be deactivated @@ -384,28 +412,13 @@ EXPORT_SYMBOL(del_timer); */ int del_timer_sync(struct timer_list *timer) { - timer_base_t *base; - unsigned long flags; - int ret = -1; - check_timer(timer); - do { - base = lock_timer_base(timer, &flags); - - if (base->running_timer == timer) - goto unlock; - - ret = 0; - if (timer_pending(timer)) { - detach_timer(timer, 1); - ret = 1; - } -unlock: - spin_unlock_irqrestore(&base->lock, flags); - } while (ret < 0); - - return ret; + for (;;) { + int ret = try_to_del_timer_sync(timer); + if (ret >= 0) + return ret; + } } EXPORT_SYMBOL(del_timer_sync); |