Re: [PATCH] Dynamic tick for x86 version 050610-1

Benjamin Herrenschmidt
2005-07-19T13:57:58Z

On Tue, 2005-07-19 at 14:51 +0800, hugang@soulinfo.com wrote:
> On Sat, Jun 18, 2005 at 04:30:32PM +1000, Benjamin Herrenschmidt wrote:
> >
> > > I'm try to port it powerpc, Here is a patch.
> > >
> > > Port Dynamic Tick Timer to new platform is easy. :)
> > > 1) Find the reprogram timer interface.
> > > 2) do a hook in the idle function.
> > >
> > > That worked on my PowerBookG4 12'.
> >
> > Did you get a measurable gain on power consumption ?
> >
> > Last time I toyed with this, I didn't.
>
> Today I do a measurable about it.
>
> First I using 2.6.12 without dynamic enable and unplug the AC power,
> I check the /proc/pmu/battery_0, like this.
> --
> flags : 00000011
> charge : 907
> max_charge : 2863
> current : -987
> voltage : 10950
> time rem. : 3600
> --
> I only intresting with current, that show the system power load.
>
> When I enable dynamic, The current can low at -900.

The numbers are repeatable ? I mean, if you actually let it settle down
in both cases ? Also, you should be careful about "parasites" in the
measurement, like pbbuttons dimming the backlight, the hard disk going
to sleep etc...

>From your numbers you get something like 10% improvement, which isn't
too bad.

Ben.