Date: Wed, 5 Nov 2014 10:21:45 +0100
From: Peter Zijlstra <peterz@infradead.org>
To: Kan Liang <kan.liang@intel.com>
Cc: eranian@google.com, linux-kernel@vger.kernel.org, mingo@redhat.com,
        paulus@samba.org, acme@kernel.org, jolsa@redhat.com,
        ak@linux.intel.com
Subject: Re: [PATCH V7 13/17] perf, x86: enable LBR callstack when recording
 callchain
Message-ID: <20141105092145.GP10501@worktop.programming.kicks-ass.net>
References: <1415156173-10035-1-git-send-email-kan.liang@intel.com>
 <1415156173-10035-14-git-send-email-kan.liang@intel.com>
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On Tue, Nov 04, 2014 at 09:56:09PM -0500, Kan Liang wrote:
> From: Yan, Zheng <zheng.z.yan@intel.com>
> 
> Only enable LBR callstack when user requires fp callgraph. The feature
> is not available when PERF_SAMPLE_BRANCH_STACK or PERF_SAMPLE_STACK_USER
> is required.
> Also, this feature only affects how to get user callchain. The kernel
> callchain is always got by frame pointers.

Since FP callchains should not change, this doesn't appear to make any
sense either.
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