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Subject: Re: [RFC] perf record: missing buildid for callstack modules
From: Namhyung Kim <namhyung@gmail.com>
Date: Fri, 08 Jan 2016 07:47:03 +0900
To: Stephane Eranian <eranian@google.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>
CC: LKML <linux-kernel@vger.kernel.org>, Jiri Olsa <jolsa@kernel.org>,
        Namhyung Kim <namhyung@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@kernel.org>,
        Adrian Hunter <adrian.hunter@intel.com>,
        "ak@linux.intel.com" <ak@linux.intel.com>
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On January 8, 2016 7:00:35 AM GMT+09:00, Stephane Eranian <eranian@google.com> wrote:
>On Thu, Jan 7, 2016 at 1:59 PM, Arnaldo Carvalho de Melo
><acme@kernel.org> wrote:
>> Em Thu, Jan 07, 2016 at 01:56:14PM -0800, Stephane Eranian escreveu:
>>> Hi,
>>>
>>> Whenever you do:
>>>
>>>     $ perf record -g -a sleep 10
>>>
>>> Perf will collect the callstack for each sample. At the end of the
>>> run, perf record
>>> adds the buildid for all dso with at least one sample. But when it
>does this, it
>>> only looks at the sampled IP and ignore the modules traversed by the
>callstack.
>>> That means that, it is not possible to uniquely identify the modules
>executed,
>>> unless they had at least one IP sample captured. But this is not
>>> always the case.
>>>
>>> How about providing an option to perf record to force collecting
>>> buildid for all IPs
>>> captured in the callstack? I understand that would cost more at the
>end of the
>>> collection, but this would be beneficial to several monitoring
>scenarios.
>>
>> I agree, would consider applying a patch that provides the option but
>> does not do this by default.
>>
>I agree, not the default.

Hi Stephane,

Please see

https://lkml.org/lkml/2015/3/22/249

Thanks,
Namhyung

-- 
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