Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750796AbWIOJ30 (ORCPT ); Fri, 15 Sep 2006 05:29:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750801AbWIOJ30 (ORCPT ); Fri, 15 Sep 2006 05:29:26 -0400 Received: from jaguar.mkp.net ([192.139.46.146]:56475 "EHLO jaguar.mkp.net") by vger.kernel.org with ESMTP id S1750796AbWIOJ3Z (ORCPT ); Fri, 15 Sep 2006 05:29:25 -0400 To: Ingo Molnar Cc: Martin Bligh , Roman Zippel , Mathieu Desnoyers , linux-kernel@vger.kernel.org, Christoph Hellwig , Andrew Morton , Ingo Molnar , Greg Kroah-Hartman , Thomas Gleixner , Tom Zanussi , ltt-dev@shafik.org, Michel Dagenais , fche@redhat.com Subject: Re: [PATCH 0/11] LTTng-core (basic tracing infrastructure) 0.5.108 References: <20060914033826.GA2194@Krystal> <20060914112718.GA7065@elte.hu> <20060914135548.GA24393@elte.hu> <20060914171320.GB1105@elte.hu> <4509BAD4.8010206@mbligh.org> <20060914203430.GB9252@elte.hu> From: Jes Sorensen Date: 15 Sep 2006 05:29:24 -0400 In-Reply-To: <20060914203430.GB9252@elte.hu> Message-ID: User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.4 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1791 Lines: 33 >>>>> "Ingo" == Ingo Molnar writes: Ingo> * Martin Bligh wrote: >> I don't think anyone is saying that static tracepoints do not have >> their limitations, or that dynamic tracepointing is useless. But >> that's not the point ... why can't we have one infrastructure that >> supports both? Preferably in a fairly simple, consistent way. Ingo> primarily because i fail to see any property of static tracers Ingo> that are not met by dynamic tracers. So to me dynamic tracers Ingo> like SystemTap are a superset of static tracers. Ingo> So my position is that what we should concentrate on is to make Ingo> the life of dynamic tracers easier (be that a handful of Ingo> generic, parametric hooks that gather debuginfo information and Ingo> add NOPs for easy patching), while realizing that static tracers Ingo> have no advantage over dynamic tracers. The parallel that springs to mind here is C++ kernel components 'I promise to only use the good parts', then next week someone else adds another pile in a worse place. Once the points are in we will never get rid of them, look at how long it took to get rid of devfs :( In addition it is guaranteed that people will not be able to agree on which points to put where, despite the claim that there will be only 30 points - sorry, I am not buying that, we have plenty of evidence to show the opposite. I looked at the old LTT code a while ago and it was pretty appalling, maybe LTTng is better, but I can't say the old code gave me a warm fuzzy feeling. 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/