Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  hrtimer: prevent migration of per CPU hrtimers
  hrtimer: mark migration state
  hrtimer: fix migration of CB_IRQSAFE_NO_SOFTIRQ hrtimers
  hrtimer: migrate pending list on cpu offline

Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

1 files changed, 14 insertions, 4 deletions

diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index 6d93dce61cbb..2f245fe63bda 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -47,14 +47,22 @@ enum hrtimer_restart {
  *      HRTIMER_CB_IRQSAFE:             Callback may run in hardirq context
  *      HRTIMER_CB_IRQSAFE_NO_RESTART:  Callback may run in hardirq context and
  *                                      does not restart the timer
- *      HRTIMER_CB_IRQSAFE_NO_SOFTIRQ:  Callback must run in hardirq context
- *                                      Special mode for tick emultation
+ *      HRTIMER_CB_IRQSAFE_PERCPU:      Callback must run in hardirq context
+ *                                      Special mode for tick emulation and
+ *                                      scheduler timer. Such timers are per
+ *                                      cpu and not allowed to be migrated on
+ *                                      cpu unplug.
+ *      HRTIMER_CB_IRQSAFE_UNLOCKED:    Callback should run in hardirq context
+ *                                      with timer->base lock unlocked
+ *                                      used for timers which call wakeup to
+ *                                      avoid lock order problems with rq->lock
  */
 enum hrtimer_cb_mode {
         HRTIMER_CB_SOFTIRQ,
         HRTIMER_CB_IRQSAFE,
         HRTIMER_CB_IRQSAFE_NO_RESTART,
-        HRTIMER_CB_IRQSAFE_NO_SOFTIRQ,
+        HRTIMER_CB_IRQSAFE_PERCPU,
+        HRTIMER_CB_IRQSAFE_UNLOCKED,
 };
 
 /*
@@ -67,9 +75,10 @@ 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 +96,7 @@ 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