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| author | Thomas Gleixner <tglx@linutronix.de> | 2008-09-03 21:36:57 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2008-10-08 19:44:42 -0700 |
| commit | fbbece349081a689d5687d9ebc769a847fdf423a (patch) | |
| tree | 63624f2c095af45a530965aff76c77be0d401a81 | |
| parent | 6141266c43db890ada7df589358b8553de2e6322 (diff) | |
| download | lwn-fbbece349081a689d5687d9ebc769a847fdf423a.tar.gz lwn-fbbece349081a689d5687d9ebc769a847fdf423a.zip | |
clockevents: prevent endless loop in periodic broadcast handler
commit d4496b39559c6d43f83e4c08b899984f8b8089b5 upstream
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -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 e1bd50cbbf5d..910b3d33867b 100644 --- a/kernel/time/tick-broadcast.c +++ b/kernel/time/tick-broadcast.c @@ -174,6 +174,8 @@ 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(); /* @@ -184,10 +186,13 @@ 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; |