Date: Mon, 1 Feb 2010 10:22:39 +0100
From: Ingo Molnar <mingo@elte.hu>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>,
       Jens Axboe <jens.axboe@oracle.com>,
       Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>,
       linux-kernel@vger.kernel.org, Paul Mackerras <paulus@samba.org>,
       Tom Zanussi <tzanussi@gmail.com>, Steven Rostedt <srostedt@redhat.com>,
       Thomas Gleixner <tglx@linutronix.de>,
       Greg Kroah-Hartman <gregkh@suse.de>
Subject: Re: [PATCH 00/12] perf lock: New subcommand "perf lock", for
 analyzing  lock statistics
Message-ID: <20100201092239.GA22578@elte.hu>
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 <4B641F4D.6090704@dcl.info.waseda.ac.jp>
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* Peter Zijlstra <peterz@infradead.org> wrote:

> On Sun, 2010-01-31 at 22:07 +0100, Frederic Weisbecker wrote:
> > 
> > - We are using the -M option from perf tools which multiplexes every
> >   event buffers, which means every cpu commit their lock events in
> >   the same buffer. Couple that with the two above reasons, it's supposed
> >   to scale at worst.
> 
> Why are you doing that? That seems like asking for trouble.. 

But as i said i already tried with -M off and it didnt cure the slowdown.

that -M was just copied over from perf sched (where it makes sense).

	Ingo
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