Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753788Ab0AYOsX (ORCPT ); Mon, 25 Jan 2010 09:48:23 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752374Ab0AYOsX (ORCPT ); Mon, 25 Jan 2010 09:48:23 -0500 Received: from casper.infradead.org ([85.118.1.10]:44624 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752165Ab0AYOsV (ORCPT ); Mon, 25 Jan 2010 09:48:21 -0500 Subject: Re: [PATCH 00/12] perf lock: New subcommand "perf lock", for analyzing lock statistics From: Peter Zijlstra To: Hitoshi Mitake Cc: Jason Baron , Ingo Molnar , linux-kernel@vger.kernel.org, Paul Mackerras , Tom Zanussi , Steven Rostedt , Thomas Gleixner , Greg Kroah-Hartman In-Reply-To: References: <1264167553-6510-1-git-send-email-mitake@dcl.info.waseda.ac.jp> <20100122164248.GA2651@redhat.com> Content-Type: text/plain; charset="UTF-8" Date: Mon, 25 Jan 2010 15:48:03 +0100 Message-ID: <1264430883.4283.1907.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1234 Lines: 33 On Mon, 2010-01-25 at 23:15 +0900, Hitoshi Mitake wrote: > > As Peter told, this patch series depends on lockdep. > But, checking dependency and tracing lock events are > essentially different things. So I think dividing these is possible. Still you need quite a lot of instrumentation at the actual lock sites, not something you'd want to have on your production machine. > But, perf depends on debugfs. > I don't know about production box well, > does your production box turns on debugfs? > It seems that debugfs is not a thing for production box... debugfs isn't a problem to have. > And I'm interesting in in-kernel histogram of locks. > Is there requirement of it? > I have some ideas (not done yet, completely). No real concrete ideas yet.. One possibility is to add a range, bucket_size tuple to perf_event_attr and store the histrogram in the mmap() area instead of samples. One difficulty is how to specify what to make that histogram over. Anyway, its all open still.. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/