Messages in this thread | | | Subject | Re: [patch] i386, numaq: enable TSCs again | From | Dave Hansen <> | Date | Fri, 25 May 2007 11:16:18 -0700 |
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On Fri, 2007-05-25 at 10:41 +0200, Ingo Molnar wrote: > * William Lee Irwin III <wli@holomorphy.com> wrote: > > > yes, that's what i meant under 'slightly async'. Some AMD CPUs are > > > like that too and sched_clock() now handles that fine. So we should > > > try my patch. > > > > Sorry, then. I took slight to mean something else. In any event I was > > only quantifying things. I've no opinion whatsoever on the impact of > > the code on NUMA-Q, only some recall of its operating characteristics. > > there's no need to apologize at all! Thanks for reminding us about the > time-scale and nature of the TSC drift on NUMAQ. I was worried that > maybe the TSC was totally unusable for some reason - but that's > fortunately not the case. So we now have one quirk less, hopefully :-)
Last I remember, it was totally useless for timekeeping, but was useful for cpu-local time measurements.
John, it's still useless for time, right? Does sched_clock() really fix it?
-- Dave
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