Thomas Gleixner eaad084bb0 NOHZ: prevent multiplication overflow - stop timer for huge timeouts
get_next_timer_interrupt() returns a delta of (LONG_MAX > 1) in case
there is no timer pending. On 64 bit machines this results in a
multiplication overflow in tick_nohz_stop_sched_tick().

Reported by: Dave Miller <davem@davemloft.net>

Make the return value a constant and limit the return value to a 32 bit
value.

When the max timeout value is returned, we can safely stop the tick
timer device. The max jiffies delta results in a 12 days timeout for
HZ=1000.

In the long term the get_next_timer_interrupt() code needs to be
reworked to return ktime instead of jiffies, but we have to wait until
the last users of the original NO_IDLE_HZ code are converted.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-29 18:11:10 -07:00
..
2007-05-23 20:14:14 -07:00
2007-05-11 05:38:25 -04:00
2007-05-11 05:38:26 -04:00
2007-05-23 20:14:12 -07:00
2007-05-23 20:14:11 -07:00
2007-05-09 12:30:55 -07:00
2007-05-09 12:30:55 -07:00
2006-12-07 08:39:36 -08:00
2006-12-04 02:00:22 -05:00
2007-05-09 07:26:28 +02:00
2007-05-09 12:30:56 -07:00
2007-05-21 09:18:19 -07:00
2007-05-11 05:38:25 -04:00
2007-05-09 12:30:55 -07:00
2007-05-09 12:30:55 -07:00
2005-04-16 15:20:36 -07:00
2007-05-23 20:14:12 -07:00
2007-05-11 08:29:35 -07:00
2006-12-07 08:39:25 -08:00
2007-05-09 08:57:56 +02:00