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To: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: mingo@elte.hu, Linus Torvalds <torvalds@osdl.org>,
       linux-kernel@vger.kernel.org, Stephane Eranian <eranian@google.com>
Subject: Re: [PATCH 0/2] perf: Use LBR for machine/oops debugging
From: Andi Kleen <andi@firstfloor.org>
References: <20100329122021.765109681@chello.nl>
Date: Mon, 29 Mar 2010 15:08:03 +0200
In-Reply-To: <20100329122021.765109681@chello.nl> (Peter Zijlstra's message of "Mon, 29 Mar 2010 14:20:21 +0200")
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Peter Zijlstra <a.p.zijlstra@chello.nl> writes:

> The LBRs are relatively cheap to keep enabled and provide some history
> to OOPSen, also some CPUs are reported to keep them over soft-reset,
> which allows us to use them to debug things like tripple faults.
>
> Therefore introduce a boot option: lbr_debug=on, which always enable
> the LBRs and will print the LBRs on CPU init and die().


die is too late. they will only contain the oops code then.

-Andi

-- 
ak@linux.intel.com -- Speaking for myself only.