1
linux/kernel/time
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
..
clockevents.c [PATCH] clockevents: remove bad designed sysfs support for now 2007-03-26 14:07:23 -07:00
clocksource.c clocksource: fix lock order in the resume path 2007-05-15 08:54:00 -07:00
jiffies.c [PATCH] fix jiffies clocksource inittime 2007-04-04 21:12:47 -07:00
Kconfig [PATCH] hrtimers: add high resolution timer support 2007-02-16 08:13:59 -08:00
Makefile Move timekeeping code to timekeeping.c 2007-05-08 11:15:06 -07:00
ntp.c Detach sched.h from mm.h 2007-05-21 09:18:19 -07:00
tick-broadcast.c Ignore bogus ACPI info for offline CPUs 2007-05-23 20:14:11 -07:00
tick-common.c highres/dyntick: prevent xtime lock contention 2007-05-08 11:15:10 -07:00
tick-internal.h highres/dyntick: prevent xtime lock contention 2007-05-08 11:15:10 -07:00
tick-oneshot.c [PATCH] clockevents: Fix suspend/resume to disk hangs 2007-03-16 19:35:25 -07:00
tick-sched.c NOHZ: prevent multiplication overflow - stop timer for huge timeouts 2007-05-29 18:11:10 -07:00
timekeeping.c timekeeping fix patch got mis-applied 2007-05-14 12:13:11 -07:00
timer_list.c Fix printk format warnings in timer_list.c 2007-05-09 12:30:50 -07:00
timer_stats.c Fix race between cat /proc/*/wchan and rmmod et al 2007-05-08 11:15:08 -07:00