Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754938AbZLJHIN (ORCPT ); Thu, 10 Dec 2009 02:08:13 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753804AbZLJHIM (ORCPT ); Thu, 10 Dec 2009 02:08:12 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:40772 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753636AbZLJHIM (ORCPT ); Thu, 10 Dec 2009 02:08:12 -0500 Date: Thu, 10 Dec 2009 08:08:00 +0100 From: Ingo Molnar To: Tim Bird , Andrew Morton , Peter Zijlstra , Arnaldo Carvalho de Melo , Li Zefan , Thomas Gleixner Cc: linux kernel , Frederic Weisbecker , Steven Rostedt Subject: Re: [PATCH 2/4] ftrace - add function_duration tracer Message-ID: <20091210070800.GB16874@elte.hu> References: <4B202778.4030801@am.sony.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4B202778.4030801@am.sony.com> User-Agent: Mutt/1.5.20 (2009-08-17) X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.5 -2.0 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1541 Lines: 40 * Tim Bird wrote: > Add function duration tracer. > > Signed-off-by: Tim Bird > --- > kernel/trace/Kconfig | 8 > kernel/trace/Makefile | 1 > kernel/trace/trace.c | 32 ++ > kernel/trace/trace_duration.c | 527 ++++++++++++++++++++++++++++++++++++++++++ > 4 files changed, 568 insertions(+) Please do it in a cleaner an more generic fashion: add a "function event" that perf can see and process, so all the output embellishment can be done outside of the kernel, in tools/perf/. We want to wind down the current maze of ftrace plugins, not extend them. We already obsoleted the following ftrace plugins: scheduler, sysprof, blktrace, kmem, scheduler, etc. There's more work ongoing and broad agreement between folks developing it that this is the way forward. The function tracer / function graph tracer is a holdout due to its complexity - but that by no means weakens the argument and the necessity to migrate it. ftrace plugins were a nice idea originally and a clear improvement over existing alternatives, but now that we've got a technicaly superior, unified event framework that can do what the old plugins did and much more, we want to improve that and not look back ... Thanks, ingo -- 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/