Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751662AbWIROrK (ORCPT ); Mon, 18 Sep 2006 10:47:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751695AbWIROrK (ORCPT ); Mon, 18 Sep 2006 10:47:10 -0400 Received: from tomts36-srv.bellnexxia.net ([209.226.175.93]:40154 "EHLO tomts36-srv.bellnexxia.net") by vger.kernel.org with ESMTP id S1751662AbWIROrJ (ORCPT ); Mon, 18 Sep 2006 10:47:09 -0400 Date: Mon, 18 Sep 2006 10:46:58 -0400 From: Mathieu Desnoyers To: Jes Sorensen Cc: karim@opersys.com, Andrew Morton , Ingo Molnar , tglx@linutronix.de, Paul Mundt , Roman Zippel , 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: <20060918144658.GC15605@Krystal> References: <450AB957.2050206@opersys.com> <20060915142836.GA9288@localhost.usen.ad.jp> <450ABE08.2060107@opersys.com> <1158332447.5724.423.camel@localhost.localdomain> <20060915111644.c857b2cf.akpm@osdl.org> <20060915181907.GB17581@elte.hu> <20060915131317.aaadf568.akpm@osdl.org> <450BCF97.3000901@sgi.com> <450C20C7.30604@opersys.com> <450E5540.4080205@sgi.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline In-Reply-To: <450E5540.4080205@sgi.com> X-Editor: vi X-Info: http://krystal.dyndns.org:8080 X-Operating-System: Linux/2.4.32-grsec (i686) X-Uptime: 10:42:47 up 26 days, 11:51, 4 users, load average: 1.42, 1.41, 1.40 User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1102 Lines: 29 Hi Jes, * Jes Sorensen (jes@sgi.com) wrote: > Everything has performance limitations, you keep running around touting > that static is the only thing thats not a problem. Now show us the > numbers! > If I may : I showed in a precedent thread that kprobes impact doubled LTTng's impact on the system. If you are interested in numbers about LTTng, here they are : "The LTTng tracer : A Low Impact Performance and Behavior Monitor for GNU/Linux" (OLS2006) http://ltt.polymtl.ca/papers/desnoyers-ols2006.pdf (and for Ingo : I haven't rerun the tests on your modified kprobes, it will come in time. But I do not really expect that 30-50 cycles compared to 1500 will make a very big difference.) Mathieu OpenPGP public key: http://krystal.dyndns.org:8080/key/compudj.gpg Key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68 - 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/