Commit 9b13df3f authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

timers: Rename del_timer_sync() to timer_delete_sync() 



The timer related functions do not have a strict timer_ prefixed namespace
which is really annoying.

Rename del_timer_sync() to timer_delete_sync() and provide del_timer_sync()
as a wrapper. Document that del_timer_sync() is not for new code.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Tested-by: default avatarGuenter Roeck <linux@roeck-us.net>
Reviewed-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
Reviewed-by: default avatarJacob Keller <jacob.e.keller@intel.com>
Reviewed-by: default avatarAnna-Maria Behnsen <anna-maria@linutronix.de>
Link: https://lore.kernel.org/r/20221123201624.954785441@linutronix.de
parent 168f6b6f

include/linux/timer.h

+14 −1
Original line number Diff line number Diff line
@@ -183,7 +183,20 @@ extern int timer_reduce(struct timer_list *timer, unsigned long expires); 
extern void add_timer(struct timer_list *timer);



extern int try_to_del_timer_sync(struct timer_list *timer);

extern int del_timer_sync(struct timer_list *timer);

extern int timer_delete_sync(struct timer_list *timer);



/**

 * del_timer_sync - Delete a pending timer and wait for a running callback

 * @timer:	The timer to be deleted

 *

 * See timer_delete_sync() for detailed explanation.

 *

 * Do not use in new code. Use timer_delete_sync() instead.

 */

static inline int del_timer_sync(struct timer_list *timer)

{

	return timer_delete_sync(timer);

}



extern void init_timers(void);

struct hrtimer;

kernel/time/timer.c

+9 −9
Original line number Diff line number Diff line
@@ -1083,7 +1083,7 @@ __mod_timer(struct timer_list *timer, unsigned long expires, unsigned int option 
		/*

		 * We are trying to schedule the timer on the new base.

		 * However we can't change timer's base while it is running,

		 * otherwise del_timer_sync() can't detect that the timer's

		 * otherwise timer_delete_sync() can't detect that the timer's

		 * handler yet has not finished. This also guarantees that the

		 * timer is serialized wrt itself.

		 */
@@ -1261,7 +1261,7 @@ EXPORT_SYMBOL_GPL(add_timer_on); 
 * @timer:	The timer to be deactivated

 *

 * The function only deactivates a pending timer, but contrary to

 * del_timer_sync() it does not take into account whether the timer's

 * timer_delete_sync() it does not take into account whether the timer's

 * callback function is concurrently executed on a different CPU or not.

 * It neither prevents rearming of the timer. If @timer can be rearmed

 * concurrently then the return value of this function is meaningless.
@@ -1397,7 +1397,7 @@ static inline void del_timer_wait_running(struct timer_list *timer) { } 
#endif



/**

 * del_timer_sync - Deactivate a timer and wait for the handler to finish.

 * timer_delete_sync - Deactivate a timer and wait for the handler to finish.

 * @timer:	The timer to be deactivated

 *

 * Synchronization rules: Callers must prevent restarting of the timer,
@@ -1419,10 +1419,10 @@ static inline void del_timer_wait_running(struct timer_list *timer) { } 
 *    spin_lock_irq(somelock);

 *                                     <IRQ>

 *                                        spin_lock(somelock);

 *    del_timer_sync(mytimer);

 *    timer_delete_sync(mytimer);

 *    while (base->running_timer == mytimer);

 *

 * Now del_timer_sync() will never return and never release somelock.

 * Now timer_delete_sync() will never return and never release somelock.

 * The interrupt on the other CPU is waiting to grab somelock but it has

 * interrupted the softirq that CPU0 is waiting to finish.

 *
@@ -1435,7 +1435,7 @@ static inline void del_timer_wait_running(struct timer_list *timer) { } 
 * * %0	- The timer was not pending

 * * %1	- The timer was pending and deactivated

 */

int del_timer_sync(struct timer_list *timer)

int timer_delete_sync(struct timer_list *timer)

{

	int ret;
@@ -1475,7 +1475,7 @@ int del_timer_sync(struct timer_list *timer) 


	return ret;

}

EXPORT_SYMBOL(del_timer_sync);

EXPORT_SYMBOL(timer_delete_sync);



static void call_timer_fn(struct timer_list *timer,

			  void (*fn)(struct timer_list *),
@@ -1497,8 +1497,8 @@ static void call_timer_fn(struct timer_list *timer, 
#endif

	/*

	 * Couple the lock chain with the lock chain at

	 * del_timer_sync() by acquiring the lock_map around the fn()

	 * call here and in del_timer_sync().

	 * timer_delete_sync() by acquiring the lock_map around the fn()

	 * call here and in timer_delete_sync().

	 */

	lock_map_acquire(&lockdep_map);