ACPI throttling changes

Nate Lawson nate at root.org
Fri Dec 12 16:36:35 PST 2003


On Fri, 12 Dec 2003, Alexandre Sunny Kovalenko wrote:
> On Tue, 9 Dec 2003 17:57:53 -0800 (PST)
> Nate Lawson <nate at root.org> wrote:
>
> > I'm working on a shared CPU frequency control driver.  One step is to
> > remove some of the autonomy of the throttling portion of acpi_cpu.
> > Please test this patch if you have a machine which supports throttling.
> > With this patch, throttling can be changed by doing:
> >
> >    sysctl hw.acpi.cpu.current_speed=X
> >
> > where X is some number between 1 and hw.acpi.cpu.max_speed.  It is no
> > longer driven by AC line transitions.  Run a CPU benchmark like this one
> > to make sure the throttling transition still works with this patch.
> >
> >     dd if=/dev/zero bs=1m count=500 | md5
> >
> > This is part of a larger work.  Don't worry, it won't be committed until
> > general CPU frequency control is done so no loss of functionality will be
> > committed.
> >
> > -Nate
>
> I do not know if it's still of any use (I just caught up on my reading),
> but for whatever it worth, results are below. To be fair results are a
> little bit surprising to myself as I "feel" better response with 'economy'
> set to 4 then with 'economy' set to 2, but of course this in unscientific.

Please cvsup, a fix for this has been committed.

-Nate


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