timers: Create detach_if_pending() and use it

Most callers of detach_timer() have the same pattern around
them. Check whether the timer is pending and eventually updating
base->next_timer.

Create detach_if_pending() and replace the duplicated code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Gilad Ben-Yossef <gilad@benyossef.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20120525214819.131246037@linutronix.de

diff --git a/kernel/timer.c b/kernel/timer.c
index 6ec7e7e0db435d722cecd601090ca4a8b3dc994a..0f70deb201516262886e3d986def0ce7620d6b2e 100644 (file)
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -654,8 +654,7 @@ void init_timer_deferrable_key(struct timer_list *timer,
 }
 EXPORT_SYMBOL(init_timer_deferrable_key);
 
-static inline void detach_timer(struct timer_list *timer,
-                               int clear_pending)
+static inline void detach_timer(struct timer_list *timer, bool clear_pending)
 {
        struct list_head *entry = &timer->entry;
 
@@ -667,6 +666,19 @@ static inline void detach_timer(struct timer_list *timer,
        entry->prev = LIST_POISON2;
 }
 
+static int detach_if_pending(struct timer_list *timer, struct tvec_base *base,
+                            bool clear_pending)
+{
+       if (!timer_pending(timer))
+               return 0;
+
+       detach_timer(timer, clear_pending);
+       if (timer->expires == base->next_timer &&
+           !tbase_get_deferrable(timer->base))
+               base->next_timer = base->timer_jiffies;
+       return 1;
+}
+
 /*
  * We are using hashed locking: holding per_cpu(tvec_bases).lock
  * means that all timers which are tied to this base via timer->base are
@@ -712,16 +724,9 @@ __mod_timer(struct timer_list *timer, unsigned long expires,
 
        base = lock_timer_base(timer, &flags);
 
-       if (timer_pending(timer)) {
-               detach_timer(timer, 0);
-               if (timer->expires == base->next_timer &&
-                   !tbase_get_deferrable(timer->base))
-                       base->next_timer = base->timer_jiffies;
-               ret = 1;
-       } else {
-               if (pending_only)
-                       goto out_unlock;
-       }
+       ret = detach_if_pending(timer, base, false);
+       if (!ret && pending_only)
+               goto out_unlock;
 
        debug_activate(timer, expires);
 
@@ -959,13 +964,7 @@ int del_timer(struct timer_list *timer)
        timer_stats_timer_clear_start_info(timer);
        if (timer_pending(timer)) {
                base = lock_timer_base(timer, &flags);
-               if (timer_pending(timer)) {
-                       detach_timer(timer, 1);
-                       if (timer->expires == base->next_timer &&
-                           !tbase_get_deferrable(timer->base))
-                               base->next_timer = base->timer_jiffies;
-                       ret = 1;
-               }
+               ret = detach_if_pending(timer, base, true);
                spin_unlock_irqrestore(&base->lock, flags);
        }
 
@@ -990,19 +989,10 @@ int try_to_del_timer_sync(struct timer_list *timer)
 
        base = lock_timer_base(timer, &flags);
 
-       if (base->running_timer == timer)
-               goto out;
-
-       timer_stats_timer_clear_start_info(timer);
-       ret = 0;
-       if (timer_pending(timer)) {
-               detach_timer(timer, 1);
-               if (timer->expires == base->next_timer &&
-                   !tbase_get_deferrable(timer->base))
-                       base->next_timer = base->timer_jiffies;
-               ret = 1;
+       if (base->running_timer != timer) {
+               timer_stats_timer_clear_start_info(timer);
+               ret = detach_if_pending(timer, base, true);
        }
-out:
        spin_unlock_irqrestore(&base->lock, flags);
 
        return ret;
@@ -1178,7 +1168,7 @@ static inline void __run_timers(struct tvec_base *base)
                        timer_stats_account_timer(timer);
 
                        base->running_timer = timer;
-                       detach_timer(timer, 1);
+                       detach_timer(timer, true);
 
                        spin_unlock_irq(&base->lock);
                        call_timer_fn(timer, fn, data);
@@ -1714,7 +1704,7 @@ static void migrate_timer_list(struct tvec_base *new_base, struct list_head *hea
 
        while (!list_empty(head)) {
                timer = list_first_entry(head, struct timer_list, entry);
-               detach_timer(timer, 0);
+               detach_timer(timer, false);
                timer_set_base(timer, new_base);
                if (time_before(timer->expires, new_base->next_timer) &&
                    !tbase_get_deferrable(timer->base))