On 30/8/07 18:01, "Mark Langsdorf" <mark...@amd.com> 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
7 messages in com.xensource.lists.xen-develRE: [Xen-devel] [PATCH][Retry 1] 4/4:...