Re: [patch] i386 dynamic ticks 2.6.13-rc4 (code reordered)

Con Kolivas
2005-08-02T07:37:05Z

On Tue, 2 Aug 2005 05:17 pm, Tony Lindgren wrote:
> * Lee Revell <rlrevell@joe-job.com> [050801 23:24]:
> > On Tue, 2005-08-02 at 15:56 +1000, Con Kolivas wrote:
> > > On Tue, 2 Aug 2005 03:52 pm, Lee Revell wrote:
> > > > On Tue, 2005-08-02 at 15:49 +1000, Con Kolivas wrote:
> > > > > As a crude data point of idle system running a full kde desktop
> > > > > environment on
> > > > > powersave with minimal backlight and just chatting on IRC I find
> > > > > it's just
> > > > > under 10% battery life difference.
> > > >
> > > > Have you tried the same test but without artsd, or with it configured
> > > > to release the sound device after some reasonable time, like 1-2s?
> > >
> > > I have it on release after 1 second already.
> >
> > Is there any difference in power use between this, and not running artsd
> > at all?
>
> Please have the pmstats from http://www.muru.com/linux/dyntick running
> in once console with pmstats 5, and then just kill programs to find out
> which ones use lots of timers. CPU monitors etc.
>
> You should get X running at about 25HZ, (which is the PIT limit usually)
> Higher ticks means means polling somewhere which totally kills any power
> savings.

Ok I seem to be bottoming out at 130Hz. I can't seem to kill off anything
more.

>
> There's still some places in kernel that also do polling as far as I
> remember:
>
> - AT keyboard if no keyboard connected
> - Netfilter code (Unverified)
>
> But this you can verify by booting to single user mode and then running
> pmstats 5, and if ticks is not below 25HZ, there's something in the kernel
> polling.

I'm removing modules and they don't seem to do anything so I'm not sure what
else to try.

Cheers,
Con