cpufreq and changing driver

[Bruno Ducrot]

On Fri, Dec 02, 2005 at 08:35:54PM +1030, Daniel O'Connor wrote:
> On Fri, 2 Dec 2005 19:35, Marco Calviani wrote:
> > > It's not present under powerd for the simple fact that to be efficient
> > > in term of not being too intrusive (kernel to user data transfers, etc),
> > > powerd can only provide a limited number of check per second (at this
> > > time, 2 per second).  But the current algorithm present in powerd is
> > > not well suited in that case.  You have to wait one demi-second
> > > for the processor being put to full speed if the system was idle
> > > before.
> >
> > Are there on the horizon any sort of plans to implement a newer and
> > more efficient algorithm to increase the number of transition per
> > second? Sorry but i've not understood why linux-cpufreqd is able to
> > cope with those without being so intrusive.....
> 
> 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
> 

-- 
Bruno Ducrot

--  Which is worse:  ignorance or apathy?
--  Don't know.  Don't care.