john stultz wrote:
> On Thu, 2009-02-26 at 22:35 +0100, Jesper Krogh wrote:
>> john stultz wrote:
>>> On Thu, Feb 26, 2009 at 12:43 PM, Jesper Krogh <[email protected]> wrote:
>>>> Linus Torvalds wrote:
>>>>> On Thu, 26 Feb 2009, Jesper Krogh wrote:
>>>>>> 2.6.26.8 doesnt have this problem.
>>>>>>
>>>>>> The "current_clocsource" is the same on both systems.
>>>>>>
>>>>>> $ cat /sys/devices/system/clocksource/clocksource0/current_clocksource
>>>>>> tsc
>>>>> What does the frequency calibrate to? It should be in the dmesg. Does it
>>>>> differ by a big amount?
>>>> Non-working:
>>>> $ dmesg | grep -i freq
>>>> [ 0.004007] Calibrating delay loop (skipped), value calculated using
>>>> timer frequency.. 4620.05 BogoMIPS (lpj=9240104)
>>>>
>>>> 2.6.26.8 doesn't have that information.
>>> I'm surprised the clocksource watchdog isn't catching it.
>>>
>>> What's the output from:
>>> cat /sys/devices/system/clocksource/clocksource0/available_clocksource
>> $ cat /sys/devices/system/clocksource/clocksource0/available_clocksource
>> tsc acpi_pm jiffies
>
> Hmm. Does booting w/ "clocksourc=acpi_pm" also show the severe (~550ppm,
> which NTP can't handle) drift?
>
>>From the dmesg, I don't see any major calibration difference right off.
>
> So I'd suspect something like TSC halting in idle could be causing
> problems, but the watchdog should catch that as well. My only guess at
> this point is that the ACPI PM is halting in idle along with the TSC.
>
> And you said this only happens under load?
That wasn't true.. I got some real sunday testing done today. A fresh
2.6.28.7 has the same problem with a load of 0.00 0.00 0.00
2.6.27.19 doesn't have problems keeping time.
--
Jesper