Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751579AbWIRIeK (ORCPT ); Mon, 18 Sep 2006 04:34:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751592AbWIRIeJ (ORCPT ); Mon, 18 Sep 2006 04:34:09 -0400 Received: from omx1-ext.sgi.com ([192.48.179.11]:62696 "EHLO omx1.americas.sgi.com") by vger.kernel.org with ESMTP id S1751579AbWIRIeI (ORCPT ); Mon, 18 Sep 2006 04:34:08 -0400 Message-ID: <450E59D3.8070003@sgi.com> Date: Mon, 18 Sep 2006 10:33:23 +0200 From: Jes Sorensen User-Agent: Thunderbird 1.5.0.4 (X11/20060527) MIME-Version: 1.0 To: Mathieu Desnoyers Cc: Ingo Molnar , Roman Zippel , Andrew Morton , tglx@linutronix.de, karim@opersys.com, Paul Mundt , 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 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> <20060915200559.GB30459@elte.hu> <20060915202233.GA23318@Krystal> <450BCAF1.2030205@sgi.com> <20060916172419.GA15427@Krystal> In-Reply-To: <20060916172419.GA15427@Krystal> X-Enigmail-Version: 0.94.0.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1671 Lines: 38 Mathieu Desnoyers wrote: > The bottom line is : > > LTTng impact on the studied phenomenon : 35% slower > > LTTng+kprobes impact on the studied phenomenon : 73% slower > > Therefore, I conclude that on this type of high event rate workload, kprobes > doubles the tracer impact on the system. For this specific benchmark, for which we have not seen the code, nor do we know what system configuration it was run on. Sorry, but even M$'s sham benchmarks generally tell you which system they used for their tests. In addition, some profiling would be interesting so we can see exactly where things go wrong and fix it. Ingo seems to be doing a good job at that even without you providing this basic info.... Anyway, despite what Karim likes to claim, this *is* the Linux way! Things don't get fixed if they are not reported broken and when they are, whoever is interested in the item will try and fix it. We are not going to cease Linux kernel development just to please Karim. The point of this discussion is that the concept of dynamic tracing is the way to go. If the code isn't 100% there today, then it should be fixed, thats *not* an excuse to add a lot of cruft based on the wrong design when we know which path to take. I know it's hard for someone to accept when he's thrown so much personal time into a project, but as Ingo keeps saying, there is a lot of value in LTT, the actual markup isn't the big issue. Jes - 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/