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Subject: Re: [DRAFT PATCH 2/3] perf: Implement Nehalem uncore pmu
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Stephane Eranian <eranian@google.com>
Cc: Lin Ming <ming.m.lin@intel.com>, Ingo Molnar <mingo@redhat.com>,
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Date: Thu, 04 Nov 2010 20:28:49 +0100
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On Tue, 2010-11-02 at 17:59 +0100, Stephane Eranian wrote:
> I think using uncore PMU to measure per-thread is pretty much useless.
> Maybe it should not even be allowed. There is no way you can correlate
> the counts you're getting to a place in your program. Or put differently,
> sampling in per-thread mode using uncore is useless. 

Right, per-task uncore event should not be allowed. I think it as simple
as setting pmu::task_ctx_nr = perf_invalid_context.