Re: cpufreq scaling strangely, system feels warm

[Steven Noonan <steven@uplinklabs.net>]

On Sat, Oct 3, 2009 at 5:54 PM, Steven Noonan <steven@uplinklabs.net> wrote:
> I have a system that's behaving as though it's under a moderate load,
> but nothing's happening and the load average is zero. If I change my
> cpufreq governor to 'conservative' or 'ondemand', the CPU immediately
> scales up to the maximum clock frequency (as though something was
> demanding that much power). The system is also very warm, which is
> abnormal even when the machine is always clocked at its maximum
> frequency.
>
> Top shows that there are no processes which are hogging the CPU, and
> /proc/interrupts doesn't reveal anything interesting (i.e. an
> interrupt storm). The only way to get my system to stay cool is to
> change the cpufreq governor to 'powersave' or 'userspace' (and then
> clock it at the lowest, manually).
>

Scratch that. It's probably an interrupt storm. 'perf top' shows
19,000 IRQs per second. And I recall that 500-1500 per second was
normal for this machine. Now the problem is figuring out where the
interrupt storm is coming from...

> I've tried 2.6.31.1 and Linus' current git tree
> (2.6.32-rc1-301-gf0a221e). My configs are attached.
>
> My system is a MacBookPro2,2. I'm running an x86_64 kernel.
>
> Any ideas of what could be going on? Am I missing something horribly obvious?
>
> - Steven
>