timer: Make try_to_del_timer_sync() the same on SMP and UP

On UP try_to_del_timer_sync() is mapped to del_timer() which does not
take the running timer callback into account, so it has different
semantics.

Remove the SMP dependency of try_to_del_timer_sync() by using
base->running_timer in the UP case as well.

[ tglx: Removed set_running_timer() inline and tweaked the changelog ]

Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Yong Zhang 2010-10-20 15:57:31 -07:00 committed by Thomas Gleixner
parent 20f33a03f0
commit 6f1bc451e6
2 changed files with 5 additions and 16 deletions

View File

@ -274,11 +274,11 @@ static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
extern void add_timer(struct timer_list *timer);
extern int try_to_del_timer_sync(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 try_to_del_timer_sync(t) del_timer(t)
# define del_timer_sync(t) del_timer(t)
#endif

View File

@ -330,15 +330,6 @@ void set_timer_slack(struct timer_list *timer, int slack_hz)
}
EXPORT_SYMBOL_GPL(set_timer_slack);
static inline void set_running_timer(struct tvec_base *base,
struct timer_list *timer)
{
#ifdef CONFIG_SMP
base->running_timer = timer;
#endif
}
static void internal_add_timer(struct tvec_base *base, struct timer_list *timer)
{
unsigned long expires = timer->expires;
@ -923,15 +914,12 @@ int del_timer(struct timer_list *timer)
}
EXPORT_SYMBOL(del_timer);
#ifdef CONFIG_SMP
/**
* try_to_del_timer_sync - Try to deactivate a timer
* @timer: timer do del
*
* 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)
{
@ -960,6 +948,7 @@ out:
}
EXPORT_SYMBOL(try_to_del_timer_sync);
#ifdef CONFIG_SMP
/**
* del_timer_sync - deactivate a timer and wait for the handler to finish.
* @timer: the timer to be deactivated
@ -1098,7 +1087,7 @@ static inline void __run_timers(struct tvec_base *base)
timer_stats_account_timer(timer);
set_running_timer(base, timer);
base->running_timer = timer;
detach_timer(timer, 1);
spin_unlock_irq(&base->lock);
@ -1106,7 +1095,7 @@ static inline void __run_timers(struct tvec_base *base)
spin_lock_irq(&base->lock);
}
}
set_running_timer(base, NULL);
base->running_timer = NULL;
spin_unlock_irq(&base->lock);
}