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| author | Thomas Gleixner <tglx@linutronix.de> | 2008-09-03 21:36:57 +0000 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2008-09-05 11:11:51 +0200 |
| commit | d4496b39559c6d43f83e4c08b899984f8b8089b5 (patch) | |
| tree | 2d2007eab7942fef1c4dee43f7be24e3bfbcfe62 /kernel | |
| parent | 7c1e76897492d92b6a1c2d6892494d39ded9680c (diff) | |
| download | lwn-d4496b39559c6d43f83e4c08b899984f8b8089b5.tar.gz lwn-d4496b39559c6d43f83e4c08b899984f8b8089b5.zip | |
clockevents: prevent endless loop in periodic broadcast handler
The reprogramming of the periodic broadcast handler was broken,
when the first programming returned -ETIME. The clockevents code
stores the new expiry value in the clock events device next_event field
only when the programming time has not been elapsed yet. The loop in
question calculates the new expiry value from the next_event value
and therefor never increases.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/time/tick-broadcast.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c index 31463d370b94..3044a88357fa 100644 --- a/kernel/time/tick-broadcast.c +++ b/kernel/time/tick-broadcast.c @@ -175,6 +175,8 @@ static void tick_do_periodic_broadcast(void) */ static void tick_handle_periodic_broadcast(struct clock_event_device *dev) { + ktime_t next; + tick_do_periodic_broadcast(); /* @@ -185,10 +187,13 @@ static void tick_handle_periodic_broadcast(struct clock_event_device *dev) /* * Setup the next period for devices, which do not have - * periodic mode: + * periodic mode. We read dev->next_event first and add to it + * when the event alrady expired. clockevents_program_event() + * sets dev->next_event only when the event is really + * programmed to the device. */ - for (;;) { - ktime_t next = ktime_add(dev->next_event, tick_period); + for (next = dev->next_event; ;) { + next = ktime_add(next, tick_period); if (!clockevents_program_event(dev, next, ktime_get())) return; |