Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932322AbWIPIcF (ORCPT ); Sat, 16 Sep 2006 04:32:05 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964776AbWIPIcF (ORCPT ); Sat, 16 Sep 2006 04:32:05 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:54984 "EHLO mx2.mail.elte.hu") by vger.kernel.org with ESMTP id S932322AbWIPIcC (ORCPT ); Sat, 16 Sep 2006 04:32:02 -0400 Date: Sat, 16 Sep 2006 10:23:28 +0200 From: Ingo Molnar To: Roman Zippel Cc: Thomas Gleixner , karim@opersys.com, Andrew Morton , Paul Mundt , Jes Sorensen , Mathieu Desnoyers , linux-kernel@vger.kernel.org, Christoph Hellwig , Ingo Molnar , Greg Kroah-Hartman , Tom Zanussi , ltt-dev@shafik.org, Michel Dagenais Subject: Re: [PATCH 0/11] LTTng-core (basic tracing infrastructure) 0.5.108 Message-ID: <20060916082328.GF6317@elte.hu> References: <1158348954.5724.481.camel@localhost.localdomain> <450B0585.5070700@opersys.com> <1158351780.5724.507.camel@localhost.localdomain> <20060915204812.GA6909@elte.hu> <20060915215112.GB12789@elte.hu> <20060915231419.GA24731@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.1i X-ELTE-SpamScore: -2.9 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.9 required=5.9 tests=ALL_TRUSTED,AWL,BAYES_50 autolearn=no SpamAssassin version=3.0.3 -3.3 ALL_TRUSTED Did not pass through any untrusted hosts 0.5 BAYES_50 BODY: Bayesian spam probability is 40 to 60% [score: 0.4998] -0.1 AWL AWL: From: address is in the auto white-list X-ELTE-VirusStatus: clean Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1376 Lines: 31 * Roman Zippel wrote: > > > > Secondly, even people who intend to _eventually_ make use of > > > > tracing, dont use it most of the time. So why should they have > > > > more overhead when they are not tracing? Again: the point is not > > > > moot because even though the user intends to use tracing, but > > > > does not always want to trace. > > > > > > I've used kernels which included static tracing and the perfomance > > > overhead is negligible for occasional use. > > > > how does this suddenly make my point, that "a marker for dynamic > > tracing has lower performance impact than a static tracepoint, on > > systems that are not being traced", "moot"? > > Why exactly is the point relevant in first place? How exactly is the > added (minor!) overhead such a fundamental problem? how could a fundamental performance difference between two markup schemes be not relevant to kernel design decisions? Which performance difference i claim derives straight from the conceptual difference between the two approaches and is thus "unfixable" (and not an "implementational issue"). 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/