Messages in this thread | | | Subject | Re: [PATCH] perf/x86: check ucode before disabling PEBS on SandyBridge | From | Peter Zijlstra <> | Date | Wed, 13 Jun 2012 17:37:52 +0200 |
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On Wed, 2012-06-13 at 07:00 -0700, H. Peter Anvin wrote: > On 06/13/2012 01:38 AM, Peter Zijlstra wrote: > > On Tue, 2012-06-12 at 13:58 -0700, H. Peter Anvin wrote: > >> even things like Nehalem + Westmere in the same system > > > > Uhm,.. how well do you expect Linux to run on a franken-system like > > that? I'm pretty sure perf will malfunction in such a setup. > > > > perf might, but I have seen such frankensystems in the field and they > work (although I haven't seen that particular combo, I have to admit.)
Thing is, if we boot on the wsm, perf could fault the system with nonexistent MSR accesses, if we boot on the nhm worst is wrong numbers I think.
I'm not really inclined to 'fix' this.. the best I'm willing to accept is a patch that would detect this situation and simply disable all hardware perf support for the platform.
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