RE: [Xen-devel] [PATCH][Retry 1] 4/4: cpufreq/PowerNow! in Xen: PowerNow! changes

["Langsdorf, Mark" <mark.langsdorf@xxxxxxx>]

> On 30/8/07 18:01, "Mark Langsdorf" <mark.langsdorf@xxxxxxx> wrote:
> 
> > Patch 4 covers the changes necessary to the PowerNow! driver
> > to make it correctly associate shared cores under Xen.
> 
> Should we have a copy of that file in powernow-k8-xen.c? Can 
> the patched file work correctly in a native Linux build?

The patch is the same patch I submitted upstream for the native
2.6.23 Linux kernel.  

In native mode, the kernel creates a cpumask for each cpu that
lists its sibling cores.  Unfortunately, Xen doesn't do that.
The patch instead reads and parses the _PSD ACPI structure,
which indicates which cores share pstates with other cores.  
(Frankly, _PSD is the right way to do it, but the other way
was easier until Linux got ACPI support for _PSD).  If Xen
were using the same kernel version as Linux, the patch wouldn't
be necessary.

-Mark Langsdorf
Operating System Research Center
AMD



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel