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Date: Mon, 11 Nov 2013 13:17:10 +0100
From: Ingo Molnar <mingo@kernel.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Namhyung Kim <namhyung@kernel.org>, Pekka Enberg <penberg@kernel.org>,
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        Rodrigo Campos <rodrigo@sdfg.com.ar>, Arun Sharma <asharma@fb.com>
Subject: Re: [RFC/PATCHSET 00/14] perf report: Add support to accumulate hist
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* Peter Zijlstra <peterz@infradead.org> wrote:

> On Wed, Nov 06, 2013 at 12:47:01PM +0100, Ingo Molnar wrote:
>
> > I'm not too worried about call-graph 'legacies': it generates such 
> > huge perf.data files which is parsed so slowly at the moment that 
> > there's very little user base ... Anyone who absolutely needs 
> > call-graph profiling uses SysProf which performs well.
> 
> Uhm, say what? I use it, and I don't use sysprof since that thing is 
> totally not usable ;-)

You aren't a typical case at all! :-)

Just look back the example where Linus tried to use call-graph profiling 
to profile a mild 60-seconds workload (a kernel build) and came away 
reporting that his perf session locked up.

I think many other people ran into that performance problem. Those who are 
using it must be using it for far shorter workloads.

Anyway, that's all fixed now, and I do think that call-graph profiling is 
one of perf's killer features - I thought that from day 1 on when I 
suggested to Frederic that it would be really important to implement it 
;-)

Thanks,

	Ingo