Merge branch 'drm-patches' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied...

[linux-2.6] / kernel / timer.c

diff --git a/kernel/timer.c b/kernel/timer.c
index d355d5a4d5ae608d2572c8f08b018952c7e52050..f35b3939e9372c5139f0588a9f728b681d225d17 100644 (file)
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -383,23 +383,19 @@ EXPORT_SYMBOL(del_timer_sync);
 static int cascade(tvec_base_t *base, tvec_t *tv, int index)
 {
        /* cascade all the timers from tv up one level */
-       struct list_head *head, *curr;
+       struct timer_list *timer, *tmp;
+       struct list_head tv_list;
+
+       list_replace_init(tv->vec + index, &tv_list);
 
-       head = tv->vec + index;
-       curr = head->next;
        /*
-        * We are removing _all_ timers from the list, so we don't  have to
-        * detach them individually, just clear the list afterwards.
+        * We are removing _all_ timers from the list, so we
+        * don't have to detach them individually.
         */
-       while (curr != head) {
-               struct timer_list *tmp;
-
-               tmp = list_entry(curr, struct timer_list, entry);
-               BUG_ON(tmp->base != base);
-               curr = curr->next;
-               internal_add_timer(base, tmp);
+       list_for_each_entry_safe(timer, tmp, &tv_list, entry) {
+               BUG_ON(timer->base != base);
+               internal_add_timer(base, timer);
        }
-       INIT_LIST_HEAD(head);
 
        return index;
 }
@@ -419,10 +415,10 @@ static inline void __run_timers(tvec_base_t *base)
 
        spin_lock_irq(&base->lock);
        while (time_after_eq(jiffies, base->timer_jiffies)) {
-               struct list_head work_list = LIST_HEAD_INIT(work_list);
+               struct list_head work_list;
                struct list_head *head = &work_list;
                int index = base->timer_jiffies & TVR_MASK;
- 
+
                /*
                 * Cascade timers:
                 */
@@ -431,8 +427,8 @@ static inline void __run_timers(tvec_base_t *base)
                                (!cascade(base, &base->tv3, INDEX(1))) &&
                                        !cascade(base, &base->tv4, INDEX(2)))
                        cascade(base, &base->tv5, INDEX(3));
-               ++base->timer_jiffies; 
-               list_splice_init(base->tv1.vec + index, &work_list);
+               ++base->timer_jiffies;
+               list_replace_init(base->tv1.vec + index, &work_list);
                while (!list_empty(head)) {
                        void (*fn)(unsigned long);
                        unsigned long data;
@@ -541,6 +537,22 @@ found:
        }
        spin_unlock(&base->lock);
 
+       /*
+        * It can happen that other CPUs service timer IRQs and increment
+        * jiffies, but we have not yet got a local timer tick to process
+        * the timer wheels.  In that case, the expiry time can be before
+        * jiffies, but since the high-resolution timer here is relative to
+        * jiffies, the default expression when high-resolution timers are
+        * not active,
+        *
+        *   time_before(MAX_JIFFY_OFFSET + jiffies, expires)
+        *
+        * would falsely evaluate to true.  If that is the case, just
+        * return jiffies so that we can immediately fire the local timer
+        */
+       if (time_before(expires, jiffies))
+               return jiffies;
+
        if (time_before(hr_expires, expires))
                return hr_expires;
 
@@ -1314,7 +1326,7 @@ static void __devinit migrate_timers(int cpu)
 }
 #endif /* CONFIG_HOTPLUG_CPU */
 
-static int __devinit timer_cpu_notify(struct notifier_block *self, 
+static int timer_cpu_notify(struct notifier_block *self,
                                unsigned long action, void *hcpu)
 {
        long cpu = (long)hcpu;