Messages in this thread | | | Subject | Re: System time drifts when processor idle. | From | john stultz <> | Date | Thu, 09 Sep 2010 10:42:05 -0700 |
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On Fri, 2010-09-03 at 14:23 +0200, jean-philippe francois wrote: > 2010/8/27 john stultz <johnstul@us.ibm.com>: > > On Fri, 2010-08-27 at 16:12 +0200, jean-philippe francois wrote: > >> My Timekeeping bug is still present, here is an updated script and log. > >> I am willing to make test, but I don't know what kind of debugging > >> info is needed. > >> > >> cat /sys/devices/system/clocksource/clocksource0/available_clocksource > >> hpet acpi_pm > >> cat /sys/devices/system/clocksource/clocksource0/current_clocksource > >> hpet > > > > Huh. hpet was not what I would have expected. > > > > > > So first, two experiments: > > > > 1) Does booting with "clock=acpi_pm" cause the issue to disappear? > > > > Hi, > > The same bug happens with clock=acpi_pm. > My apologies for a previous mail where I said it was not hapenning with acpi_pm. > > With both clock, the timekeeping gap augments by amount of 5 minutes.
Huh. So this still seems strange, but assuming we're still using the hpet for irqs, its possible the event somehow gets pushed back 5 minutes and we miss an timekeeping interval accumulation (with acpi_pm, the counter wraps ever 5 seconds or so, so we could miss many accumulation intervals and still be 5 minutes off if the tick timer was late).
Again, seeing if the issue goes away with nohz=off would be helpful.
thanks -john
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