Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932478AbWIZTOO (ORCPT ); Tue, 26 Sep 2006 15:14:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932479AbWIZTON (ORCPT ); Tue, 26 Sep 2006 15:14:13 -0400 Received: from tomts36.bellnexxia.net ([209.226.175.93]:8606 "EHLO tomts36-srv.bellnexxia.net") by vger.kernel.org with ESMTP id S932478AbWIZTON (ORCPT ); Tue, 26 Sep 2006 15:14:13 -0400 Date: Tue, 26 Sep 2006 15:08:49 -0400 From: Mathieu Desnoyers To: Jeremy Fitzhardinge Cc: Martin Bligh , "Frank Ch. Eigler" , Masami Hiramatsu , prasanna@in.ibm.com, Andrew Morton , Ingo Molnar , 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 , Karim Yaghmour , Pavel Machek , Joe Perches , "Randy.Dunlap" , "Jose R. Santos" Subject: Re: [PATCH] Linux Kernel Markers 0.13 for 2.6.17 Message-ID: <20060926190849.GA2280@Krystal> References: <20060925233349.GA2352@Krystal> <20060925235617.GA3147@Krystal> <45187146.8040302@goop.org> <20060926002551.GA18276@Krystal> <20060926004535.GA2978@Krystal> <45187C0E.1080601@goop.org> <20060926025924.GA27366@Krystal> <4518B4A0.6070509@goop.org> <20060926180414.GA10497@Krystal> <4519781D.9040503@goop.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline In-Reply-To: <4519781D.9040503@goop.org> X-Editor: vi X-Info: http://krystal.dyndns.org:8080 X-Operating-System: Linux/2.4.32-grsec (i686) X-Uptime: 15:05:00 up 34 days, 16:13, 4 users, load average: 0.31, 0.15, 0.13 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: 1822 Lines: 48 * Jeremy Fitzhardinge (jeremy@goop.org) wrote: > Mathieu Desnoyers wrote: > >Hi, > > > >Ok, so as far as I can see, we can only control the execution flow by > >modifying > >values in the output list of the asm. > > > >Do you think the following would work ? > > > > > >#define MARK_JUMP(name, format, args...) \ > > do { \ > > char condition; \ > > asm volatile( ".section .markers, \"a\";\n\t" \ > > ".long 0f;\n\t" \ > > ".previous;\n\t" \ > > "0:\n\t" \ > > "movb $0,%1;\n\t" \ > > : "+m" (__marker_sequencer), \ > > "=r" (condition) : ); \ > > if(unlikely(condition)) { \ > > MARK_CALL(name, format, ## args); \ > > } \ > > } while(0) > > > > Yep, that looks reasonable. Though you could just directly test a > per-marker enable flag, rather than using "condition"... > The goal of the local variable "condition" here is that it will be forced to be a register (=r in asm output), so there is no memory load involved (immediate value). I am not sure I understand your suggestion correctly.. do you mean having a per-marker flag that would be loaded and tested at every marker site ? Mathieu OpenPGP public key: http://krystal.dyndns.org:8080/key/compudj.gpg Key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68 - 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/