Date: Tue, 20 Jul 2004 12:00:59 -0700 From: Nate Lawson <nate@root.org> To: Ted Faber <faber@ISI.EDU> Cc: frebsd-hackers@freebsd.org Subject: Re: Dell Latitude 610 CPU clock rate degrading (debug info included) Message-ID: <40FD6BEB.4060102@root.org> In-Reply-To: <20040720165016.GA35412@pun.isi.edu> References: <20040720165016.GA35412@pun.isi.edu>
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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. > 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. > Attached are a sysctl hw.acpi before and after the speed change and a > dmesg from a -v boot up to when the states change. The attachments are > in that order. ASL is at > http://www.isi.edu/~faber/tmp/faber-dell-L610.asl > > Please let me know if I can help debug this. -Nate
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