powerd freezes system on lower cpu speeds
jhb at freebsd.org
Thu Aug 28 02:27:13 UTC 2008
On Wednesday 27 August 2008 09:40:20 am cpghost wrote:
> I'm building a new system with an AMD Phenom 9350e Quad-Core:
> FreeBSD phenom.example.net 7.1-PRERELEASE FreeBSD 7.1-PRERELEASE #0:
> Tue Aug 26 19:49:24 UTC 2008 root at phenom.example.net:/usr/obj/usr/\
> src/sys/GENERIC i386
> Everything's running smoothly, until I start powerd. As soon as
> that happens, the system freezes hard. Trying powerd in the foreground
> with -v shows that it decreased the frequencies a few times, but then
> hangs the system.
> So I've tried this manually:
> # sysctl dev.cpu.0.freq_levels
> dev.cpu.0.freq_levels: 1985/-1 1736/-1 1488/-1 1240/-1 992/-1 744/-1
> 496/-1 248/-1
> # sysctl dev.cpu.0.freq
> dev.cpu.0.freq: 1985
> powerd freezed the system after reaching 1240 when trying 992. If I set
> the frequency manually down to 1240 with:
> # sysctl dev.cpu.0.freq=1240
> everything's fine. But as soon as I try setting it further down
> (992, 744, 496 or 248), the system freezes too, just the same
> as with powerd. This is 100% reproducible.
> So what's going on here?
Hard to say. My HP nc6220 laptop gets into a lockup where it spends all its
time processing ACPI events (I think for some of the thermal monitoring the
BIOS does) if I drop the CPU speed below 400. I just set
debug.cpufreq.lowest in /boot/loader.conf.
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