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authorThomas Gleixner <tglx@linutronix.de>2009-01-05 11:28:23 +0100
committerIngo Molnar <mingo@elte.hu>2009-01-05 13:14:34 +0100
commite3f1d883740b09e5116d4d4e30a6a6987264a83c (patch)
treecdc2f35a46b094197a9ea8c8280a7c8f209cc501 /kernel
parenta6037b61c2f5fc99c57c15b26d7cfa58bbb34008 (diff)
downloadop-kernel-dev-e3f1d883740b09e5116d4d4e30a6a6987264a83c.zip
op-kernel-dev-e3f1d883740b09e5116d4d4e30a6a6987264a83c.tar.gz
hrtimer: fixup comments
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>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/hrtimer.c20
1 files changed, 9 insertions, 11 deletions
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index b68e98f..aa024f2 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -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);
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