Messages in this thread | | | Subject | Re: hangcheck watchdog triggers if clock=pit. Missing code in monotonic_clock_pit()? | From | john stultz <> | Date | Mon, 12 Apr 2004 11:16:25 -0700 |
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On Sat, 2004-04-10 at 06:35, Denis Vlasenko wrote: > linux-2.6.5/arch/i386/kernel/time.c: > ==================================== > /* monotonic_clock(): returns # of nanoseconds passed since time_init() > * Note: This function is required to return accurate > * time even in the absence of multiple timer ticks. > */ [snip] > linux-2.6.5/arch/i386/kernel/timers/timer_pit.c: > ================================================ > static unsigned long long monotonic_clock_pit(void) > { > return 0; > }
Part of the problem is that the PIT timesource cannot account for lost ticks, thus we cannot strictly conform to the monotonic_clock()interface.
So either we just return (jiffies_64 * TICK_NSEC), and just have an exception to the rule, or the hangcheck watchdog needs to know what to do when monotonic_clock always returns zero.
Joel: Do you have a preference?
thanks -john
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