From mboxrd@z Thu Jan  1 00:00:00 1970
From: john stultz <johnstul@us.ibm.com>
Subject: Re: System time drifts when processor idle.
Date: Fri, 27 Aug 2010 11:11:48 -0700
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To: jean-philippe francois <jp.francois@cynove.com>
Cc: Lin Ming <lin@ming.vg>, venki@google.com, "H. Peter Anvin" <hpa@zytor.com>, linux-acpi@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>, jslaby@suse.cz

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?

2) Does booting with "nohz=off" cause the issue to disappear?


Venkatesh: You have any experience with HPETs that halt in idle?

thanks
-john