Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932538AbWIVOcB (ORCPT ); Fri, 22 Sep 2006 10:32:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932537AbWIVOcB (ORCPT ); Fri, 22 Sep 2006 10:32:01 -0400 Received: from pentafluge.infradead.org ([213.146.154.40]:19948 "EHLO pentafluge.infradead.org") by vger.kernel.org with ESMTP id S932538AbWIVOcA (ORCPT ); Fri, 22 Sep 2006 10:32:00 -0400 Date: Fri, 22 Sep 2006 15:31:02 +0100 From: Christoph Hellwig To: Mathieu Desnoyers Cc: Ingo Molnar , Martin Bligh , "Frank Ch. Eigler" , Masami Hiramatsu , prasanna@in.ibm.com, Andrew Morton , Paul Mundt , linux-kernel , Jes Sorensen , Tom Zanussi , Richard J Moore , Michel Dagenais , Christoph Hellwig , Greg Kroah-Hartman , Thomas Gleixner , William Cohen , ltt-dev@shafik.org, systemtap@sources.redhat.com, Alan Cox Subject: Re: [PATCH] Linux Kernel Markers 0.5 for Linux 2.6.17 (with probe management) Message-ID: <20060922143102.GA24414@infradead.org> Mail-Followup-To: Christoph Hellwig , Mathieu Desnoyers , Ingo Molnar , Martin Bligh , "Frank Ch. Eigler" , Masami Hiramatsu , prasanna@in.ibm.com, Andrew Morton , Paul Mundt , linux-kernel , Jes Sorensen , Tom Zanussi , Richard J Moore , Michel Dagenais , Greg Kroah-Hartman , Thomas Gleixner , William Cohen , ltt-dev@shafik.org, systemtap@sources.redhat.com, Alan Cox References: <20060921160009.GA30115@Krystal> <20060921160656.GA24774@elte.hu> <20060921214248.GA10097@Krystal> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060921214248.GA10097@Krystal> User-Agent: Mutt/1.4.2.1i X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1800 Lines: 36 I hate AOL-style me-toos, but there's nothing to add to this mail. Thanks for this coherent writeup Mathieu. On Thu, Sep 21, 2006 at 05:42:48PM -0400, Mathieu Desnoyers wrote: > Hi Ingo, > > I clearly expressed my position in the previous emails, so did you. You argued > about a use of tracing that is not relevant to my vision of reality, which is : > > - Embedded systems developers won't want a breakpoint-based probe > - High performance computing users won't want a breakpoint-based probe > - djprobe is far away from being in an acceptable state on architectures with > very inconvenient erratas (x86). > - kprobe and djprobe cannot access local variables in every cases > > For those reasons, I prefer a jump-over-call approach which lets gcc give us the > local variables. No need of DWARF or SystemTAP macro Kung Fu. Just C and a > loadable module. > > By no means is it a replacement for a completely dynamic breakpoint-based > instrumentation mechanism. I really think that both mechanism should coexist. > > This is my position : I let the distribution/user decide what is appropriate for > their use. My goal is to provide them a flexible mechanism that takes the > multiple variety of uses in account without performance impact if they are not > willing to pay it to benefit from tracing. > > With all due respect, yes, there are Linux users different from the typical > Redhat client. If your vision is still limited to this scope after a 500 > emails debate, I am afraid that there is very little I can do about it in > one more. - 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/