RE: ACPI throttling changes

On Wed, 10 Dec 2003, John Baldwin wrote:
> On 10-Dec-2003 Nate Lawson 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.
>
> We need to support using throttling for passive cooling btw.  My new laptop
> I just got has no active cooling support, but does have _TC1 and _TC2 objects
> in its thermal zone.  Are you going to add that?

Eventually.  The first step is to get a general frequency control driver
working.  It will also do throttling as well as speedstep, longrun, etc.
The step after that is to change acpi_thermal to use that driver for
passive cooling.

-Nate