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Date: Mon, 09 Sep 2013 07:11:11 -0700
From: David Ahern <dsahern@gmail.com>
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To: Jiri Olsa <jolsa@redhat.com>
CC: Peter Zijlstra <peterz@infradead.org>, linux-kernel@vger.kernel.org,
        Corey Ashford <cjashfor@linux.vnet.ibm.com>,
        Frederic Weisbecker <fweisbec@gmail.com>, Ingo Molnar <mingo@elte.hu>,
        Namhyung Kim <namhyung@kernel.org>, Paul Mackerras <paulus@samba.org>,
        Arnaldo Carvalho de Melo <acme@redhat.com>,
        Andi Kleen <ak@linux.intel.com>
Subject: Re: [PATCHv2 00/25] perf tool: Add support for multiple data file
 storage
References: <1378031796-17892-1-git-send-email-jolsa@redhat.com> <20130909111749.GP31370@twins.programming.kicks-ass.net> <20130909113640.GA16401@krava.redhat.com> <20130909115518.GA26785@twins.programming.kicks-ass.net> <20130909140339.GB16401@krava.redhat.com>
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On 9/9/13 7:03 AM, Jiri Olsa wrote:
> my usage currently is to having this running during the day:
> (well whenever I remember to run it.. ;-) )
>
>    [jolsa@krava perf]$ sudo ./perf record -g -M 1m -a
>
> and checking report when the system or app get stuck
>
> with multiple files I can just easily (or automaticaly)
> remove old ones without restarting session

Aren't you losing potentially important events by doing that -- FORK, 
COMM, MMAP?

I have a flight recorder style command that address this problem 
(long-running/daemons) by processing task events and then stashing the 
sample events on a time-ordered list with chopping to maintain the time 
window.

David