Re: P4/i845 Strange clock drifting

[Chris Wilson <chris@jakdaw.org>]

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An update...
 
> I've now applied your patch so that APIC's get enabled even though the
> bios has disabled them. 
> 
> I really should have saved the dmi messages to another machine when the
> machine first came up as it appears to have crashed now :(
> 
> The machine was completely idle other than for an ssh session running
> ntpdate every ten minutes (my original problem is that the clock appears
> to stop/slow down periodically). 

Back without APIC now - and the machine is stable again. Clock is still
screwed however.

> > This should work (and is known to work on many P6 and K7 boards),
> > but your BIOS may have problems with the local APIC.
> > - does apm --suspend work? does the resume afterwards work?
> 
> I don't have APM support compiled in and will have disabled anything power
> management related in the BIOS setup.

Last night I set another machine doing:

(while sleep 600; do ssh screwedbox ntpdate goodbox; done) | tee ntp.log

The results (attached) are interesting. It appears that my clock drift
problem occurs every hour.  Perhaps it is APM related?? Load doesn't seem
to make any difference. And there's never two consecutive ntpdate's that
are a long way out - suggesting that whenever the problem occurs it's then
fixed temporarily when ntpdate sets the clock.

Anyone have any suggestions as to what to try next? Shall I try compiling
a kernel with APM support and see if I can turn off anything that might be
causing troubs? I'm *sure* I turned off any mention of power management in
the BIOS....

Regards,

Chris

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