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Subject: Re: [RFC][PATCH 08/11] perf, x86: Implement simple LBR support
From: Peter Zijlstra <peterz@infradead.org>
To: Stephane Eranian <eranian@google.com>
Cc: mingo@elte.hu, linux-kernel@vger.kernel.org, paulus@samba.org,
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Date: Thu, 04 Mar 2010 21:23:25 +0100
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On Thu, 2010-03-04 at 19:18 +0100, Peter Zijlstra wrote:
> What is currently implemented is that we loose history at the point a
> new task schedules in an LBR using event.
> 
This also matches CPU errata AX14, AJ52 and AAK109 which states that a
task switch may produce faulty LBR state, so clearing history after a
task switch seems the best thing to do.