clock too slow - big time offset with ntpdate
smithi at nimnet.asn.au
Thu May 3 05:24:03 UTC 2007
On Thu, 3 May 2007, Martin Dieringer wrote:
> On Wed, 2 May 2007, Doug Barton wrote:
> > Martin Dieringer wrote:
> >> On Wed, 2 May 2007, John Walthall wrote:
> >>> On Tue, May 01, 2007 at 08:50:10PM +0200, Martin Dieringer wrote:
> >>>> I think it has to do with powerd, if I kill that, the time stays correct.
> >>> With powerd enabled, are you able to maintain a "reasonably"
> >>> correct time with frequent NTP syncronizations? Sorry if it's just
> >>> me, but I am not quite clear about that, from what has been written
> >>> already.
> >> I would have to update every minute at least and would still be more
> >> than 5 seconds off.
> > I think you misunderstand how ntpd works vs. how ntpdate works.
> > ntpd is a daemon, so you don't run it every minute, it runs in the
> > background and keeps the clock up to date.
> > Turn off all of the power management, and any other service that
> > might be affecting the clock, and then reboot. If your system is
> > able to maintain correct time under these circumstances, start
> > adding things in until you find the culprit and let us know.
> both laptops can keep the time without powerd. apm is enabled, but not
> acpi. as soon as I start powerd or change cpu speed, time gets a few
> seconds off.
> It doesn't matter whether I use ntpd or ntpdate.
> (ntpdate at system startup makes no sense as I have to dialup first).
If using ppp or mpd, you could run ntpdate from a link-up script.
But to address the underlying problem, quoting from earlier, you said:
> > Now I got following while playing sound on the Compaq:
> > kernel: calcru: runtime went backwards from 183711700 usec to 183167434 usec for pid 12 (swi4: clock sio)
> > here I have a working clock, but also intermittent sound output
To which I suggested, after a bit of hunting:
> http://lists.freebsd.org/pipermail/freebsd-stable/ searching for
> 'calcru: runtime went backwards' provides many hits, as does google;
> seems it could be a number of things, perhaps choice of timecounter.
Also a bit further down in the FAQ:
'5.25. Why does the clock on my laptop keep incorrect time?'
Have you had a look at those FAQ entries? Might they be relevant?
How about showing us /var/run/dmesg.boot for at least one of these two
machines? I'm still curious as to what Timecounter & HZ is selected:
show us 'sysctl kern.timecounter' and 'sysctl -a | grep -i cpu' ?
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