Re: [PATCH 01/17] perf util: Save pid-cmdline mapping into tracing header

From: Namhyung Kim
Date: Mon Aug 05 2013 - 03:18:00 EST

Hi Arnaldo,

On Wed, 31 Jul 2013 11:07:46 -0300, Arnaldo Carvalho de Melo wrote:
> Em Wed, Jul 31, 2013 at 09:51:54AM +0900, Namhyung Kim escreveu:
>> 2013-07-30 ìí 10:28, Arnaldo Carvalho de Melo ì ê:
>> >Em Tue, Jul 30, 2013 at 06:18:58PM +0900, Namhyung Kim escreveu:
>> >>Current trace info data lacks the saved cmdline mapping which is
>> >>needed for pevent to find out the comm of a task. Add this and bump
>> >>up the version number so that perf can determine its presence when
>> >>reading.
>> >Can't we get this from the PERF_RECORD_COMM synthesized at the beginning
>> >of the session + the kernel generated ones for new threads?
>> >We would just call machine__find_thread() and use thread->comm, etc, no?
>> Yes, I think it's doable. However it needs an additional perf event
>> only to generate the COMM events. So I decided not to do it and
> I don't think this is a problem, its in line with Ingo's suggestion of a
> new perf ioctl to ask the kernel to generate PERF_RECORD_MMAP events for
> existing threads.

Hmm.. could you please give me a link of the thread?

And what kind of event should be used then?

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