Re: [PATCH] cpufreq: Fix ondemand governor powersave_bias executiontime misuse

[Arjan van de Ven]

On 11/8/2010 6:45 AM, Youquan Song wrote:
> > On 11/5/2010 11:19 AM, Youquan Song wrote:
> > > Ondemand governor use powersave_bias tunable to do aggressive power save by
> > > decrease CPU average frequency. The average frequency achieve by adjust low and
> > > high frequency's execution time proportion during one sample time interval.
> > >
> > > Current kernel, only the high frequency executes in time proportion, but the low
> > > frequency wrongly execute in one whole sample time interval when powersave_bias
> > > is set.
> > >
> > > The patch fix it by set low frequency execution time to it deserved.
> > >
> > > Signed-off-by: Youquan Song<youquan.song@xxxxxxxxx>
> > > ---
> >
> > while your patch looks correct, I think the whole feature is wonky and
> > likely ought to be removed...........
> powersave_bias should be a useful feature, which give user an
> opportunity to set the CPU to work at wider average frequency accord to real
>   workload requirement, not just CPU frequency specific at P0,P1,...Pn.
> At the same time, it meets end user power comsumpation requirement in
> some degree.
> Unfortunately, it does not work for a long time.

in all measurements I've done... the intermediate states (between P1 and 
Pn) seem to not be power efficient.....

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