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

Tony Lindgren
2005-07-25T10:12:38Z

* Benjamin Herrenschmidt <benh@kernel.crashing.org> [050719 06:55]:
> 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.

Just quick update here, I'm back from vacation and will try to
post updated dyn-tick patch soon with the PPC patch integrated.

Tony