hrtimer: fixup comments
authorThomas Gleixner <tglx@linutronix.de>
Mon, 5 Jan 2009 10:28:23 +0000 (11:28 +0100)
committerIngo Molnar <mingo@elte.hu>
Mon, 5 Jan 2009 12:14:34 +0000 (13:14 +0100)
Clean up the comments

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
kernel/hrtimer.c

index b68e98f..aa024f2 100644 (file)
@@ -1143,9 +1143,9 @@ static void __run_hrtimer(struct hrtimer *timer)
        spin_lock(&cpu_base->lock);
 
        /*
-        * Note: We clear the CALLBACK bit after enqueue_hrtimer to avoid
-        * reprogramming of the event hardware. This happens at the end of this
-        * function anyway.
+        * Note: We clear the CALLBACK bit after enqueue_hrtimer and
+        * we do not reprogramm the event hardware. Happens either in
+        * hrtimer_start_range_ns() or in hrtimer_interrupt()
         */
        if (restart != HRTIMER_NORESTART) {
                BUG_ON(timer->state != HRTIMER_STATE_CALLBACK);
@@ -1514,14 +1514,12 @@ static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base,
                __remove_hrtimer(timer, old_base, HRTIMER_STATE_MIGRATE, 0);
                timer->base = new_base;
                /*
-                * Enqueue the timers on the new cpu, but do not reprogram 
-                * the timer as that would enable a deadlock between
-                * hrtimer_enqueue_reprogramm() running the timer and us still
-                * holding a nested base lock.
-                *
-                * Instead we tickle the hrtimer interrupt after the migration
-                * is done, which will run all expired timers and re-programm
-                * the timer device.
+                * Enqueue the timers on the new cpu. This does not
+                * reprogram the event device in case the timer
+                * expires before the earliest on this CPU, but we run
+                * hrtimer_interrupt after we migrated everything to
+                * sort out already expired timers and reprogram the
+                * event device.
                 */
                enqueue_hrtimer(timer, new_base);