Re: [PATCH] - Fix get_model_name() for mixed cpu type systems

Stephane Eranian
2006-10-18T22:25:49Z

Jack,

On Wed, Oct 18, 2006 at 04:55:30PM -0500, Jack Steiner wrote:
> On Wed, Oct 18, 2006 at 02:44:13PM -0700, Stephane Eranian wrote:
> > Jack,
> >
> > The perfmon subsystem will not work correctly if you mix
> > Madison and Montecito in the same box. And there is not an
> > easy way to make it work with such configuration. Performance
> > counters are different between the two models.
>
> The failing case that I ran into was a mixture of rev 5 & rev 7
> montecitos:
> Intel(r) Itanium(r) 2 Processor 1.6GHz with 24M L3 Cache for 533MHz Platforms
> Intel(r) Itanium(r) 2 Processor 1.6GHz with 18M L3 Cache for 533MHz Platforms
>
> I assume that will work ok. Right?
>
Yes, I think for this you are ok.

> However, there is also a patch that Russ Anderson pushed last week (at least
> I think he pushed it). We are planning to support systems with mixtures of both
> madison & montecito. Sounds like we have a problem :-(
>
Yes, I recall seeing something along those lines not too long ago...
With the existing perfmon v2.0, All the PMU description tables are compiled in.

I think what we could do is to detect we have a mixed (family) configuration
and drop to the generic (architected) PMU with only 4 counters and 2 events. That
is, I am afraid, the best we could do.

--
-Stephane