Re: High interrupt load on VIA C3 machine

On 2007-Aug-31 20:52:58 +0100, Bruce Cran <bruce_at_cran.org.uk> wrote:
>This appears to be an issue with powerd/cpufreq - disabling powerd reduces 
>the interrupt load to a couple of percent at most, and the clock interrupt 
>task now only accumulates CPU time very slowly (previously it was using 7% 
>CPU all the time).

I'm not familiar with the VIA CPUs but how slowly can powerd make the
CPU run?  The top extract you posted show the system was idle so its
likely that powerd had wound the clock to a minimum.  The amount of
code executed by the interrupt handlers remains the same but will take
longer at slower clock speeds so the percenatage is higher.

You can experiment for yourself by enabling only cpufreq and using
sysctl.  dev.cpu.0.freq_levels lists all supported possible CPU rates
and you can change the clock frequency by assigning dev.cpu.0.freq.

-- 
Peter Jeremy