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Date: Sun, 6 Apr 2008 11:01:21 +0200
From: Guido van Rooij <guido@gvr.org>
To: Peter Jeremy <peterjeremy@optushome.com.au>
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Cc: freebsd-stable@freebsd.org
Subject: Re: NTP on amd74 + powernow issues
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On Sat, Apr 05, 2008 at 09:15:32AM +1100, Peter Jeremy wrote:
> On Fri, Apr 04, 2008 at 07:46:05PM +0200, Guido van Rooij wrote:
> >I've got a amd64 system where I;m using powernow. I am using th i8254
> >timecounter.
> 
> I'm using ACPI-fast on amd64 without problems.  i8254 should not be
> affected by PowerNow! but ACPI-fast should be listed as preferable.
> Do you have a particular reason for using the i8254?
> 
> >Especially the largers resets (+10 seconds) are annoying as e.g. dovecot
> >bails out.
> >
> >Any clue on how this could be fixed?
> 
> Any time resets are abnormal.  There's nothing obviously wrong with
> your NTP servers.  I have had problems in the past with the ntpd PLL
> saturating and demonstrating symptoms similar to what you are seeing.
> 
> What does your ntp.drift contain?  My guess is that it's either +500
> or -500.  If this is true, I suggest you:

gvr# cat /var/db/ntpd.drift 
-288.731

> - stop ntpd
> - delete ntp.drift
> - enable loopstats collection in your ntp.conf (optional)
> - run "ntptime -f 0"
> - run "/etc/rc.d/ntpdate start"
> - run "/etc/rc.d/ntpd start"
> 
> This will force ntpd to re-calibrate and, hopefully, it will stabilise,
> though this can take a day or so.

Didn't work :-(

-Guido