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    SubjectRe: [PATCH 0/13] Time: Generic Timeofday Subsystem (v B10)
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    On Tue, 2005-11-15 at 21:53 +0100, Ingo Molnar wrote:
    > * john stultz <johnstul@us.ibm.com> wrote:
    >
    > > > idle=poll does seem to fix the major clock drift problem. There may
    > > > still be an issue, but it's much smaller:
    > > >
    > > > 2.6.14-mm2-todb10:
    > > > 14 Nov 21:50:57 offset: -0.025373 drift: -22404.0 ppm
    > > > 14 Nov 21:51:59 offset: -1.577053 drift: -24985.4603175 ppm
    > > > 14 Nov 21:53:00 offset: -3.104569 drift: -25012.9032258 ppm
    > > >
    > > > 2.6.14-mm2-todb10 with idle=poll:
    > > > 14 Nov 21:37:59 offset: 5.9e-05 drift: 63.0 ppm
    > > > 14 Nov 21:39:00 offset: 0.003207 drift: 51.7903225806 ppm
    > >
    > > Hmm. It seems the c3 compensation is triggering when it shouldn't, or
    > > maybe its over compensating.
    > >
    > > I can't reproduce it on my laptop. Do you recall if in previous tests
    > > you saw anything like this? I'm trying to narrow down if its just a
    > > difference in hardware or if something in the c3 idle code changed.
    >
    > it's with an earlier queue of yours, but maybe it's related: i have a
    > report that HPET causes HRT inaccuracies (e.g. sleeps for 20 msecs last
    > 21 msecs). If all HPET options are turned off in the .config then
    > everything is fine and accurate.

    Hmm. HPET would be separate from this, I believe. I suspect that could
    be related to the HPET legacy replacement functionality, where the HPET
    is triggering the timer interrupts. Not something I changed, but
    probably should be looked into.

    thanks
    -john




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