Re: cpufreq default governor

From: William Heimbigner
Date: Tue Apr 24 2007 - 09:25:58 EST

On Tue, 24 Apr 2007, Michal Piotrowski wrote:
On 24/04/07, William Heimbigner <icxcnika@xxxxxxxxxx> wrote:
On Tue, 24 Apr 2007, Michal Piotrowski wrote:

> On 24/04/07, William Heimbigner <icxcnika@xxxxxxxxxx> wrote:
> > On Tue, 24 Apr 2007, Michal Piotrowski wrote:
> > > > > Hi William,
> > > > > > On 24/04/07, William Heimbigner <icxcnika@xxxxxxxxxx> wrote:
> > > > Question: is there some reason that kconfig does not allow for
> > > > default
> > > > governors of conservative/ondemand/powersave?
> > > > > > Performance?
> > > > > > > I'm not aware of any reason why one of those governors could not > > > > be
> > > > used
> > > > as default.
> > > > > > My hardware doesn't work properly with ondemand governor. I hear
> > > strange noises when frequency is changed.
> > > > > > > That doesn't mean it isn't working, though.
> > I didn't say that cpufreq ondemand is broken. It's a hardware problem.
> > > I here weird noises if the cpu
> > is clocked anywhere from 333MHz to 1GHz (sounds like an RD-D2 beeping
> > noises in ultra high pitch?)
> > Yes, something like that.

Is it actually "not working" though, even at the hardware level?

It works, but for me this sounds are very weird ;)

To my
knowledge those noises are normal, and aren't even signs of a harware
problem. I believe it is the natural result of changing frequencies at any
time. If you change frequencies, especially in the low end of available
frequencies, you should hear a very brief noise. A governor such as
ondemand, which is rapidly switching the frequency from say, 333 MHz to
2.66 GHz, is likely to make this much more noticable.

Ok, it might be normal behavior. I might be wrong, but IMO users
prefer speed and no strange sounds as default setting.

I agree! My suggestion, however, is that if they do want a different scheduler as the default, they can choose one.

There are some cases in which this could be very useful. A couple examples would be the processor with poor cooling that overheats easily, or a laptop with a poor battery.

However, on second thought with regards to Kconfig, would it be feasible to have performance always be the default, unless a "cpufreqgov=conservative" arguement was specified on the command line?

This would be less susceptible to users complaining that their cpu is chirping all of a sudden.

William Heimbigner
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