Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754717AbYLSW5i (ORCPT ); Fri, 19 Dec 2008 17:57:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751742AbYLSW5a (ORCPT ); Fri, 19 Dec 2008 17:57:30 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:49080 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751068AbYLSW5a (ORCPT ); Fri, 19 Dec 2008 17:57:30 -0500 Date: Fri, 19 Dec 2008 23:57:17 +0100 From: Ingo Molnar To: Pekka Paalanen Cc: Steven Rostedt , =?iso-8859-1?Q?Fr=E9d=E9ric?= Weisbecker , Pekka J Enberg , linux-kernel@vger.kernel.org, Markus Metzger Subject: Re: ftrace behaviour (was: [PATCH] ftrace: introduce tracing_reset_online_cpus() helper) Message-ID: <20081219225717.GK13409@elte.hu> References: <20081220004453.50aec846@daedalus.pq.iki.fi> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20081220004453.50aec846@daedalus.pq.iki.fi> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 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: 1017 Lines: 26 * Pekka Paalanen wrote: > > I'm actually against the idea of reseting a trace everytime we enable it. > > That is: > > > > echo 1 > /debug/tracing/tracing_enabled > > > > This should not reset the tracer. I actually do tracing where I disable > > and enable it around areas I am interested in. I want all tracing, not > > just the last one. > > But doesn't this go against the fact, that you need to write 0 there to > be able to change the ring buffer size? hm, that ftrace behavior is silly. Steve, i think i mentioned this a long time ago and i thought it got fixed? Changing the ring buffer size is a slow op, it should include an implicit reset and should be plug-and-play with no dependencies of having to stop the trace or something. 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/