Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751478AbWION5X (ORCPT ); Fri, 15 Sep 2006 09:57:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751475AbWION5X (ORCPT ); Fri, 15 Sep 2006 09:57:23 -0400 Received: from smtp.ocgnet.org ([64.20.243.3]:746 "EHLO smtp.ocgnet.org") by vger.kernel.org with ESMTP id S1751469AbWION5W (ORCPT ); Fri, 15 Sep 2006 09:57:22 -0400 Date: Fri, 15 Sep 2006 22:57:09 +0900 From: Paul Mundt To: Roman Zippel Cc: Karim Yaghmour , Jes Sorensen , Ingo Molnar , 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 Subject: Re: [PATCH 0/11] LTTng-core (basic tracing infrastructure) 0.5.108 Message-ID: <20060915135709.GB8723@localhost.usen.ad.jp> References: <20060914135548.GA24393@elte.hu> <20060914171320.GB1105@elte.hu> <20060914181557.GA22469@elte.hu> <4509A54C.1050905@opersys.com> <450A9EC9.9080307@opersys.com> <20060915132052.GA7843@localhost.usen.ad.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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: 1661 Lines: 31 On Fri, Sep 15, 2006 at 03:41:03PM +0200, Roman Zippel wrote: > > On Fri, Sep 15, 2006 at 08:38:33AM -0400, Karim Yaghmour wrote: > > I didn't get the "instrumentation is evil" mantra from this thread, > > rather "static tracepoints are good, so long as someone else is > > maintaining them". The issue comes down to who ends up maintaining the > > trace points, > > The claim that these tracepoints would be maintainance burden is pretty > much unproven so far. The static tracepoint haters just assume the kernel > will be littered with thousands of unrelated tracepoints, where a good > tracepoint would only document what already happens in that function, so > that the tracepoint would be far from something obscure, which only few > people could understand and maintain. > Again, this works fine so long as the number of static tracepoints is small and manageable, but it seems like there's a division between what the subsystem developer deems as meaningful and what someone doing the tracing might want to look at. Static tracepoints are completely subjective, LTT proved that this was a problem regarding general code-level intrusiveness when the number of tracepoints in relatively close locality started piling up based on what people considered arbitrarily useful, and LTTng doesn't appear to do anything to address this. This doesn't really match my definition of a neglible maintenance burden.. - 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/