cpufreq and changing driver

[Marco Calviani]

Hi list,

2005/12/2, Bruno Ducrot <ducrot at poupinou.org>:


> > I don't see why you can't run powerd more frequently, I do.. Unless your ACPI
> > has a problem that means the transition is slow.
>
> I'm sure this could not be done under Linux without a lot of
> problems (it is required to use the /proc things and it's too slow in
> that case).
>
> > I can't imagine that doing 5 (or even 50) syscalls a second is a big CPU load
> > unless there is a specific problem with sysctls or the cpufreq
> > infrastructure.
>
> If that's possible being not so intrusive with, say 50 syscalls under FreeBSD,
> then all I said above is indeed stupid crap.
>
> > I run powerd like this ->
> > /usr/sbin/powerd -i 90 -r 30 -a adaptive -b adaptive -n adaptive -p 200
> >

Well, i've tried decreasing the polling interval, but there is an
increased powerd cpu load: at 100ms polling interval the cpu load is
to an astonishing 20% circa, which i think it's too much for a normal
use. The sampling rate with ondemand governor in linux kernel is 10ms
but cpufreqd is at 0.6% on average cpu load.

Regards,
MC