Re: MSR support for x86
Stephan Meyer (sensei@wiesel.de)
Mon, 3 Mar 1997 22:11:52 +0100 (MET)
On Mon, 3 Mar 1997, Tim Hollebeek wrote:
> H. Peter Anvin writes ...
> >
> > > >
> > > > I think /dev/msr on a multiprocessor should read the CPU the process
> > > > is running on.
> > >
> > > That may be a different CPU at different points however.
> > >
> >
> > Tricky situation. Maybe we should either have when the port is
> > opened, or have /dev/msr0, /dev/msr1... on its own major #.
>
> How about writing the cpu # you want to a field in
> /dev/msr, then reading the stats?
This is just as problematic as writing to a special field in /dev/hda
<ironic on>.
For the processor instructions, a full 32-bit are used to identify the
needed register. What if Intel places a new MSR right at the position of
the "special field"
cheers, Stephan
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Stephan Meyer
+49-89-4301114
Stephan.Meyer@munich.netsurf.de
http://fatman.mathematik.tu-muenchen.de/~meyer/
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