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Subject: Re: PIT, TSC and power management [was: Re: 2.6.0-test3 "loosing
	ticks"]
From: john stultz <johnstul@us.ibm.com>
To: Jamie Lokier <jamie@shareable.org>
Cc: Charles Lepple <clepple@ghz.cc>, lkml <linux-kernel@vger.kernel.org>
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On Fri, 2003-08-15 at 16:12, Jamie Lokier wrote:
> john stultz wrote:
> > Well, depending on how ntp is compiled, it could use stime, rather then
> > settimeofday. This causes ntp to set the time on average .5 seconds off
> > the desired time. Since .5 is outside the .128 sec slew boundary, ntp 
> > will do another step adjustment which has the same poor accuracy. This
> > results in ntp just hopping back and forth around the desired time. 
> 
> On my more-or-less Red Hat 9 system, it would be quite surprising if
> the ntpd which works with 2.4 suddenly stopped working...

Yea, I don't think this is the issue. RH9 doesn't have this problem. I
was just explaining why I asked if ntpdate -b <server> set the time
properly on his box.

Really I think the amd76x_pm module is cause, as it seems to changes the
cpu frequency and I'm suspecting it doesn't use the cpu_freq notifiers.
I'd be quite interested to see if the issue still appears when you're
not running that module. 

thanks
-john




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