Re: [GIT PULL] TSC sched_clock overflow workaround

[Ingo Molnar <mingo@elte.hu>]

* John Stultz <johnstul@us.ibm.com> wrote:

> Hey Thomas, Ingo,
> 	I thought Peter had sent this on, but apparently its not landed yet, so
> I wanted to make sure you got it.
> 
> After ~208 days, the sched_clock multiplication overflows and 
> causes some false positives in the softlockup watchdog. I don't 
> think there are any actual panics going on, as an earlier related 
> div by zero issue was already fixed. However, the false positives 
> do continue to worry folks.
> 
> We still need a proper fix, which will probably be in part making 
> sched_clock do periodic accumulation, as well as possibly changing 
> users of sched_clock (like the softlockup watchdog) use timekeeping 
> timestamps rather then sched_clock.

I'd *much* rather see a real fix for this than an ugly workaround 
that disables a very real speedup.

Thanks,

	Ingo