Dell Latitude 610 CPU clock rate degrading (debug info included)

[Ted Faber]

On Tue, Jul 20, 2004 at 12:00:59PM -0700, Nate Lawson wrote:
> Ted Faber wrote:
> >My Dell Latatude 610 is having its clock rate go from 1000 Mhz to 733
> >Mhz under -CURRENT that was cvsupped and installed yesterday.  I'm
> >honestly not sure how long this has been happening, since I only got the
> >clock speed monitor (the one that runs under gkrellm) hooked up a couple
> >weeks ago.  I hooked it up because the machine seemed slow.  It had been
> >happening for a couple weeks at least.
> >
> >The rate seems to change after using the CPU hard for a while - a big
> >compile, like make buildworld seems to do it, though even a few minutes
> >of compilation seems sufficient.
> >
> >When the CPU speed changes I get a message in the logs saying 
> >
> >cpu0: Performance states changed
> >
> >The state never seems to change back to a high performance one.  I've
> >configured the BIOS not to do power management with the AC connected,
> >and this happens with the AC connected.
> 
> This transition is being done by the BIOS for passive cooling.  We can't 
> control it until the cpufreq driver is committed.  When the system gets 
> hot, the BIOS steps the processor down to 733 mhz but the timecounters have 
> no way of knowing it happened.

Thanks for the info.  If you've got a list of people to ping when the
cpufreq driver appears, put me on it.  I'll be watching for the HEADSUP
in any case.

> 
> >I tried booting without ACPI, but my time of day clock ran consistenty
> >slow - which might mean that the same degredation was occurring without
> >the OS readjusting for it.  In any case it wasn't clear that no ACPI
> >helped.
> 
> Same problem.  What timecounter are you using?  Switching away from TSC 
> would help this.

With ACPI there's no clock skew problem, so that's how I've been
running.  Just for my information, how might I switch timecounters?  (It
sounds like it won't solve the problem to switch away from ACPI, but I'm
curious).

Thanks again for your quick response.

-- 
Ted Faber
http://www.isi.edu/~faber           PGP: http://www.isi.edu/~faber/pubkeys.asc
Unexpected attachment on this mail? See http://www.isi.edu/~faber/FAQ.html#SIG 
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