From: Peter Zijlstra <peterz@infradead.org>
To: kan.liang@intel.com
Cc: eranian@google.com, linux-kernel@vger.kernel.org,
mingo@redhat.com, paulus@samba.org, acme@kernel.org,
ak@linux.intel.com, "Yan, Zheng" <zheng.z.yan@intel.com>
Subject: Re: [PATCH V5 14/16] perf, x86: enable LBR callstack when recording callchain
Date: Wed, 24 Sep 2014 16:21:10 +0200 [thread overview]
Message-ID: <20140924142110.GG2805@worktop.programming.kicks-ass.net> (raw)
In-Reply-To: <1410358153-421-15-git-send-email-kan.liang@intel.com>
On Wed, Sep 10, 2014 at 10:09:11AM -0400, kan.liang@intel.com wrote:
> From: Kan Liang <kan.liang@intel.com>
>
> If a task specific event wants user space callchain but does not want
> branch stack sampling, enable the LBR call stack facility implicitly.
> The LBR call stack facility can help perf to get user space callchain
> in case of there is no frame pointer.
>
> Note: this feature only affects how to get user callchain. The kernel
> callchain is always got by frame pointers.
Yeah, don't like this either. Suppose you have sane userspace (with
framepointers enabled) then you're now loosing the better option.
next prev parent reply other threads:[~2014-09-24 14:21 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-10 14:08 [PATCH V5 00/16] perf, x86: Haswell LBR call stack support kan.liang
2014-09-10 14:08 ` [PATCH V5 01/16] perf, x86: Reduce lbr_sel_map size kan.liang
2014-09-24 10:50 ` Peter Zijlstra
2014-09-10 14:08 ` [PATCH V5 02/16] perf, core: introduce pmu context switch callback kan.liang
2014-09-24 11:23 ` Peter Zijlstra
2014-09-24 13:13 ` Peter Zijlstra
2014-09-10 14:09 ` [PATCH V5 03/16] perf, x86: use context switch callback to flush LBR stack kan.liang
2014-09-10 14:09 ` [PATCH V5 04/16] perf, x86: Basic Haswell LBR call stack support kan.liang
2014-09-10 14:09 ` [PATCH V5 05/16] perf, core: pmu specific data for perf task context kan.liang
2014-09-10 14:09 ` [PATCH V5 06/16] perf, core: always switch pmu specific data during context switch kan.liang
2014-09-10 14:09 ` [PATCH V5 07/16] perf, x86: allocate space for storing LBR stack kan.liang
2014-09-10 14:09 ` [PATCH V5 08/16] perf, x86: track number of events that use LBR callstack kan.liang
2014-09-24 12:53 ` Peter Zijlstra
2014-10-07 2:59 ` Liang, Kan
2014-10-07 15:19 ` Peter Zijlstra
2014-09-10 14:09 ` [PATCH V5 09/16] perf, x86: Save/resotre LBR stack during context switch kan.liang
2014-09-24 13:33 ` Peter Zijlstra
2014-09-10 14:09 ` [PATCH V5 10/16] perf, core: simplify need branch stack check kan.liang
2014-09-24 13:55 ` Peter Zijlstra
2014-09-10 14:09 ` [PATCH V5 11/16] perf, core: Pass perf_sample_data to perf_callchain() kan.liang
2014-09-24 14:15 ` Peter Zijlstra
2014-10-07 3:00 ` Liang, Kan
2014-10-07 15:24 ` Peter Zijlstra
2014-10-07 15:50 ` Liang, Kan
2014-10-07 16:29 ` Peter Zijlstra
2014-09-10 14:09 ` [PATCH V5 12/16] perf, x86: use LBR call stack to get user callchain kan.liang
2014-09-10 14:09 ` [PATCH V5 13/16] perf, x86: re-organize code that implicitly enables LBR/PEBS kan.liang
2014-09-10 14:09 ` [PATCH V5 14/16] perf, x86: enable LBR callstack when recording callchain kan.liang
2014-09-24 14:21 ` Peter Zijlstra [this message]
2014-10-07 3:00 ` Liang, Kan
2014-10-07 15:25 ` Peter Zijlstra
2014-10-07 16:04 ` Liang, Kan
2014-09-10 14:09 ` [PATCH V5 15/16] perf, x86: disable FREEZE_LBRS_ON_PMI when LBR operates in callstack mode kan.liang
2014-09-10 14:09 ` [PATCH V5 16/16] perf, x86: Discard zero length call entries in LBR call stack kan.liang
-- strict thread matches above, loose matches on Subject: below --
2014-07-07 6:28 [PATCH v5 00/16] perf, x86: Haswell LBR call stack support Yan, Zheng
2014-07-07 6:28 ` [PATCH v5 14/16] perf, x86: enable LBR callstack when recording callchain Yan, Zheng
2001-01-08 2:31 [PATCH V5 10/16] perf, core: simplify need branch stack check kan.liang
2001-01-08 2:32 ` [PATCH V5 14/16] perf, x86: enable LBR callstack when recording callchain kan.liang
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