Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965355AbWIRElF (ORCPT ); Mon, 18 Sep 2006 00:41:05 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965334AbWIRElF (ORCPT ); Mon, 18 Sep 2006 00:41:05 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:36254 "EHLO mx2.mail.elte.hu") by vger.kernel.org with ESMTP id S965355AbWIRElC (ORCPT ); Mon, 18 Sep 2006 00:41:02 -0400 Date: Mon, 18 Sep 2006 06:32:48 +0200 From: Ingo Molnar To: Karim Yaghmour Cc: Theodore Tso , Nicholas Miell , Paul Mundt , linux-kernel , Ingo Molnar , Jes Sorensen , Andrew Morton , Roman Zippel , Tom Zanussi , Richard J Moore , "Frank Ch. Eigler" , Michel Dagenais , Mathieu Desnoyers , Christoph Hellwig , Greg Kroah-Hartman , Thomas Gleixner , William Cohen , "Martin J. Bligh" Subject: Re: tracepoint maintainance models Message-ID: <20060918043248.GB19843@elte.hu> References: <20060917112128.GA3170@localhost.usen.ad.jp> <20060917143623.GB15534@elte.hu> <1158524390.2471.49.camel@entropy> <20060917230623.GD8791@elte.hu> <450DEEA5.7080808@opersys.com> <20060918005624.GA30835@elte.hu> <450DFFC8.5080005@opersys.com> <20060918033027.GB11894@elte.hu> <20060918035216.GF9049@thunk.org> <450E1F6F.7040401@opersys.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <450E1F6F.7040401@opersys.com> 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: 0.5000] -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: 1925 Lines: 42 * Karim Yaghmour wrote: > Theodore Tso wrote: > > I *think* what Karim is trying to claim is that LTT also has some > > dynamic capabilities, and isn't a pure static tracing system. But if > > that's the case, I don't understand why LTT and SystemTap can't just > > merge and play nice together.... > > That's been the thrust of my intervention here. [...] indeed, and i severely misunderstood your points in this regard. Now i have re-read some of your earlier points, and in particular: >> And finally, do realize that in 2000 I personally contacted the head >> of the DProbes project IBM in order to foster common development, >> following which ltt was effectively modified in order to allow >> dynamic instrumentation of the kernel ... and now i'm red faced - i was wrong about this fundamental aspect of your position. Please accept my apologies! so regarding the big picture we are largely on the same page in essence i think - sub-issues non-withstanding :-) As long as LTT comes with a facility that allows the painless moving of a static LTT markup to a SystemTap script, that would come quite a bit closer to being acceptable for upstream acceptance in my opinion. The curious bit is: why doesnt LTT integrate SystemTap yet? Is it the performance aspect? Some of the extensive hooking you do in LTT could be aleviated to a great degree if you used dynamic probes. For example the syscall entry hackery in LTT looks truly scary. I cannot understand that someone who does tracing doesnt see the fundamental strength of SystemTap - i think that in part must have lead to my mistake of assuming that you opposed SystemTap. 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/