Messages in this thread | | | Date | Wed, 5 Feb 2014 14:29:36 -0500 (EST) | From | Vince Weaver <> | Subject | Re: [PATCH] perf,x86,p6: Add userspace RDPMC quirk for P6 |
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On Wed, 5 Feb 2014, Peter Zijlstra wrote:
> On Wed, Feb 05, 2014 at 02:16:43PM -0500, Vince Weaver wrote: > > On Wed, 5 Feb 2014, Peter Zijlstra wrote: > > > > > P6 class machines can die hard when PCE gets enabled due to CPU > > > errata. The safe way it so disable it by default and keep it disabled. > > > > > > See errata 26: > > > > so you take an errata applicable to a subset of Pentium Pro steppings and > > apply it to the whole p6 line (which includes the whole way up to Pentium > > III)? > > > > Or am I missing something in the documentation you link to? > > I forgot it went all the way to P-III, let me try and find the other > erratas.
from the document you linked it looks like it was fixed by the Pentium Pro stepping sB1 (6.1.9).
Has someone actually hit this bug? People used PAPI/perfctr on these machines for years, and it uses rdpmc by default so I would think it would show up if it were an issue. I should check the perfctr code to see if it had some sort of check.
Vince
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