1 files changed, 25 insertions, 3 deletions

diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 580bc66ae136..ac2f6d6d4868 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -1591,11 +1591,12 @@ static void __cpuinit init_hrtimers_cpu(int cpu)
 
 #ifdef CONFIG_HOTPLUG_CPU
 
-static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base,
+static int migrate_hrtimer_list(struct hrtimer_clock_base *old_base,
                                 struct hrtimer_clock_base *new_base)
 {
         struct hrtimer *timer;
         struct rb_node *node;
+        int raise = 0;
 
         while ((node = rb_first(&old_base->active))) {
                 timer = rb_entry(node, struct hrtimer, node);
@@ -1607,7 +1608,27 @@ static void migrate_hrtimer_list(struct hrtimer_clock_base *old_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_NO_SOFTIRQ
+                 * (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_INACTIVE) {
+                        timer->state = HRTIMER_STATE_PENDING;
+                        list_add_tail(&timer->cb_entry,
+                                      &new_base->cpu_base->cb_pending);
+                        raise = 1;
+                }
+#endif
         }
+        return raise;
 }
 
 #ifdef CONFIG_HIGH_RES_TIMERS
@@ -1652,8 +1673,9 @@ 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]))
+                        raise = 1;
         }
 
         if (migrate_hrtimer_pending(old_base, new_base))