Merge commit 'linus/master' into merge-linus

[pandora-kernel.git] / kernel / hrtimer.c

diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 2bd230b..51ee90b 100644 (file)
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -672,13 +672,14 @@ static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
                         */
                        BUG_ON(timer->function(timer) != HRTIMER_NORESTART);
                        return 1;
-               case HRTIMER_CB_IRQSAFE_NO_SOFTIRQ:
+               case HRTIMER_CB_IRQSAFE_PERCPU:
+               case HRTIMER_CB_IRQSAFE_UNLOCKED:
                        /*
                         * This is solely for the sched tick emulation with
                         * dynamic tick support to ensure that we do not
                         * restart the tick right on the edge and end up with
                         * the tick timer in the softirq ! The calling site
-                        * takes care of this.
+                        * takes care of this. Also used for hrtimer sleeper !
                         */
                        debug_hrtimer_deactivate(timer);
                        return 1;
@@ -1266,7 +1267,8 @@ static void __run_hrtimer(struct hrtimer *timer)
        timer_stats_account_hrtimer(timer);
 
        fn = timer->function;
-       if (timer->cb_mode == HRTIMER_CB_IRQSAFE_NO_SOFTIRQ) {
+       if (timer->cb_mode == HRTIMER_CB_IRQSAFE_PERCPU ||
+           timer->cb_mode == HRTIMER_CB_IRQSAFE_UNLOCKED) {
                /*
                 * Used for scheduler timers, avoid lock inversion with
                 * rq->lock and tasklist_lock.
@@ -1517,7 +1519,7 @@ void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *task)
        sl->timer.function = hrtimer_wakeup;
        sl->task = task;
 #ifdef CONFIG_HIGH_RES_TIMERS
-       sl->timer.cb_mode = HRTIMER_CB_IRQSAFE_NO_SOFTIRQ;
+       sl->timer.cb_mode = HRTIMER_CB_IRQSAFE_UNLOCKED;
 #endif
 }
 
@@ -1661,29 +1663,95 @@ static void __cpuinit init_hrtimers_cpu(int cpu)
 
 #ifdef CONFIG_HOTPLUG_CPU
 
-static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base,
-                               struct hrtimer_clock_base *new_base)
+static int migrate_hrtimer_list(struct hrtimer_clock_base *old_base,
+                               struct hrtimer_clock_base *new_base, int dcpu)
 {
        struct hrtimer *timer;
        struct rb_node *node;
+       int raise = 0;
 
        while ((node = rb_first(&old_base->active))) {
                timer = rb_entry(node, struct hrtimer, node);
                BUG_ON(hrtimer_callback_running(timer));
                debug_hrtimer_deactivate(timer);
-               __remove_hrtimer(timer, old_base, HRTIMER_STATE_INACTIVE, 0);
+
+               /*
+                * Should not happen. Per CPU timers should be
+                * canceled _before_ the migration code is called
+                */
+               if (timer->cb_mode == HRTIMER_CB_IRQSAFE_PERCPU) {
+                       __remove_hrtimer(timer, old_base,
+                                        HRTIMER_STATE_INACTIVE, 0);
+                       WARN(1, "hrtimer (%p %p)active but cpu %d dead\n",
+                            timer, timer->function, dcpu);
+                       continue;
+               }
+
+               /*
+                * Mark it as STATE_MIGRATE not INACTIVE otherwise the
+                * timer could be seen as !active and just vanish away
+                * under us on another CPU
+                */
+               __remove_hrtimer(timer, old_base, HRTIMER_STATE_MIGRATE, 0);
                timer->base = new_base;
                /*
                 * Enqueue the timer. Allow reprogramming of the event device
                 */
                enqueue_hrtimer(timer, new_base, 1);
+
+#ifdef CONFIG_HIGH_RES_TIMERS
+               /*
+                * Happens with high res enabled when the timer was
+                * already expired and the callback mode is
+                * HRTIMER_CB_IRQSAFE_UNLOCKED (hrtimer_sleeper). The
+                * enqueue code does not move them to the soft irq
+                * pending list for performance/latency reasons, but
+                * in the migration state, we need to do that
+                * otherwise we end up with a stale timer.
+                */
+               if (timer->state == HRTIMER_STATE_MIGRATE) {
+                       timer->state = HRTIMER_STATE_PENDING;
+                       list_add_tail(&timer->cb_entry,
+                                     &new_base->cpu_base->cb_pending);
+                       raise = 1;
+               }
+#endif
+               /* Clear the migration state bit */
+               timer->state &= ~HRTIMER_STATE_MIGRATE;
+       }
+       return raise;
+}
+
+#ifdef CONFIG_HIGH_RES_TIMERS
+static int migrate_hrtimer_pending(struct hrtimer_cpu_base *old_base,
+                                  struct hrtimer_cpu_base *new_base)
+{
+       struct hrtimer *timer;
+       int raise = 0;
+
+       while (!list_empty(&old_base->cb_pending)) {
+               timer = list_entry(old_base->cb_pending.next,
+                                  struct hrtimer, cb_entry);
+
+               __remove_hrtimer(timer, timer->base, HRTIMER_STATE_PENDING, 0);
+               timer->base = &new_base->clock_base[timer->base->index];
+               list_add_tail(&timer->cb_entry, &new_base->cb_pending);
+               raise = 1;
        }
+       return raise;
+}
+#else
+static int migrate_hrtimer_pending(struct hrtimer_cpu_base *old_base,
+                                  struct hrtimer_cpu_base *new_base)
+{
+       return 0;
 }
+#endif
 
 static void migrate_hrtimers(int cpu)
 {
        struct hrtimer_cpu_base *old_base, *new_base;
-       int i;
+       int i, raise = 0;
 
        BUG_ON(cpu_online(cpu));
        old_base = &per_cpu(hrtimer_bases, cpu);
@@ -1696,14 +1764,21 @@ static void migrate_hrtimers(int cpu)
        spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING);
 
        for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
-               migrate_hrtimer_list(&old_base->clock_base[i],
-                                    &new_base->clock_base[i]);
+               if (migrate_hrtimer_list(&old_base->clock_base[i],
+                                        &new_base->clock_base[i], cpu))
+                       raise = 1;
        }
 
+       if (migrate_hrtimer_pending(old_base, new_base))
+               raise = 1;
+
        spin_unlock(&old_base->lock);
        spin_unlock(&new_base->lock);
        local_irq_enable();
        put_cpu_var(hrtimer_bases);
+
+       if (raise)
+               hrtimer_raise_softirq();
 }
 #endif /* CONFIG_HOTPLUG_CPU */