linux-kernel - Re: [PATCH] tools, perf: Allow the user to disable time stamps

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Message-ID: <20140325210109.GH15074@tassilo.jf.intel.com>
Date:	Tue, 25 Mar 2014 14:01:09 -0700
From:	Andi Kleen <ak@...ux.intel.com>
To:	Stephane Eranian <eranian@...gle.com>
Cc:	Andi Kleen <andi@...stfloor.org>,
	Arnaldo Carvalho de Melo <acme@...radead.org>,
	Ingo Molnar <mingo@...nel.org>,
	LKML <linux-kernel@...r.kernel.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Namhyung Kim <namhyung@...nel.org>,
	Jiri Olsa <jolsa@...hat.com>
Subject: Re: [PATCH] tools, perf: Allow the user to disable time stamps

> 
> Timestamp are useful to order samples during reporting.
> How do you do with it if you monitor multi-threaded (multi-cpu)
> workloads. This is only good for single thread or single CPU
> measurements. Or am I missing something?

For a perf report order doesn't matter (except against mmaps)
The CPUs are still separated of course

You're right for some special analysis it matters, that is why
it is only an option. 

But for the standard "only care about perf report and 
don't care about about program startup" case it's a nice saving.

-Andi
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