cpuspeed [Re: ACPI throttling]

[Per Bjornsson]

On Thu, 2004-07-01 at 07:58, Matthias Saou wrote:
>  IIRC, the default /etc/cpuspeed.conf sets the CPU to run at the
> lowest speed all the time when running on the battery, and also checks
> temperature.

If you look carefully at the default /etc/cpuspeed.conf that line is
actually commented out so cpuspeed is effectively only run with the '-d'
option, nothing else is changed from the compiled-in defaults (which I
believe are effectively '-p 10 25' and nothing else). On my laptop it
certainly seems to change speeds even when running on battery (and
that's the way I want it, keeping it at the slowest state is just
annoying for processor-intensive tasks.)

> I'm not sure I see the point of checking the load to change the CPU speed,
> as many other things than CPU usage can make it increase (disk I/O and
> network I/O come to mind). Anyway, the way cpuspeed works with my Centrino
> laptop by default is fine for me : 600MHz, and it increases when I start
> compiling stuff, then goes down again when it finishes :-)

Seems more or less fine for me too, except that I have a hard time
getting it to speed up/slow down quickly enough for my taste, I adjusted
it to check every 0.2 seconds instead of every 2 s and it still seems to
take a few seconds to speed up and slow down, at least if the
/proc/cpuinfo is to be trusted... I would like for the processor to
speed up quickly and then drop dead real fast when it's not needed any
longer!

/Per

-- 
Per Bjornsson <perbj at stanford.edu>
Ph.D. Candidate, Department of Applied Physics, Stanford University