Re: [PATCH 1/2] x86, perf: Remove warning for zero PEBS status

From	Peter Zijlstra <peterz@infradead.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH 1/2] x86, perf: Remove warning for zero PEBS status
Date	2015-12-03 22:30 +0100
Message-ID	<qBJBU-22d-5@gated-at.bofh.it> (permalink)
References	<qBJBU-22d-3@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Thu, Dec 03, 2015 at 01:22:19PM -0800, Andi Kleen wrote:
> From: Andi Kleen <ak@linux.intel.com>
> 
> The recent change 75f80859b1 (... Robustify PEBS buffer drain)
> causes lots of warnings on different CPUs before Skylake
> when running PEBS intensive workloads.
> 
> They can have a zero status field in the PEBS record when
> PEBS is racing with clearing of GLOBAl_STATUS.

Ah, so _that_ is the explanation! Please put that in a comment near that
code. This has long puzzled me.

Thanks for digging into that.
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[PATCH 1/2] x86, perf: Remove warning for zero PEBS status Andi Kleen <andi@firstfloor.org> - 2015-12-03 22:30 +0100
  Re: [PATCH 1/2] x86, perf: Remove warning for zero PEBS status Peter Zijlstra <peterz@infradead.org> - 2015-12-03 22:30 +0100

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