---

yaml
---
r: 110090
b: refs/heads/master
c: b00c1a9
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 41e1022eae71707f1ce6801a746f70b1e57b7567
+refs/heads/master: b00c1a99e7758f794923c61e5cd55268d61c9469

trunk/include/linux/hrtimer.h

@@ -67,9 +67,10 @@ enum hrtimer_cb_mode {
  * 0x02		callback function running
  * 0x04		callback pending (high resolution mode)
  *
- * Special case:
+ * Special cases:
  * 0x03		callback function running and enqueued
  *		(was requeued on another CPU)
+ * 0x09		timer was migrated on CPU hotunplug
  * The "callback function running and enqueued" status is only possible on
  * SMP. It happens for example when a posix timer expired and the callback
  * queued a signal. Between dropping the lock which protects the posix timer
@@ -87,6 +88,7 @@ enum hrtimer_cb_mode {
 #define HRTIMER_STATE_ENQUEUED	0x01
 #define HRTIMER_STATE_CALLBACK	0x02
 #define HRTIMER_STATE_PENDING	0x04
+#define HRTIMER_STATE_MIGRATE	0x08
 
 /**
  * struct hrtimer - the basic hrtimer structure

trunk/kernel/hrtimer.c

@@ -1602,7 +1602,13 @@ static int migrate_hrtimer_list(struct hrtimer_clock_base *old_base,
 		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);
+
+		/*
+		 * 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
@@ -1620,13 +1626,15 @@ static int migrate_hrtimer_list(struct hrtimer_clock_base *old_base,
 		 * state, we need to do that otherwise we end up with
 		 * a stale timer.
 		 */
-		if (timer->state == HRTIMER_STATE_INACTIVE) {
+		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;
 }