Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751818AbWIZAGk (ORCPT ); Mon, 25 Sep 2006 20:06:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751819AbWIZAGk (ORCPT ); Mon, 25 Sep 2006 20:06:40 -0400 Received: from tomts22-srv.bellnexxia.net ([209.226.175.184]:44211 "EHLO tomts22-srv.bellnexxia.net") by vger.kernel.org with ESMTP id S1751818AbWIZAGj (ORCPT ); Mon, 25 Sep 2006 20:06:39 -0400 Date: Mon, 25 Sep 2006 19:56:17 -0400 From: Mathieu Desnoyers To: 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 , Jeremy Fitzhardinge , 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: <20060925235617.GA3147@Krystal> References: <20060925233349.GA2352@Krystal> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline In-Reply-To: <20060925233349.GA2352@Krystal> X-Editor: vi X-Info: http://krystal.dyndns.org:8080 X-Operating-System: Linux/2.4.32-grsec (i686) X-Uptime: 19:51:23 up 33 days, 21:00, 3 users, load average: 0.29, 0.13, 0.16 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: 2551 Lines: 85 Just as a precision : The following sequence (please refer to the code below for local symbols 1 and 2) : 1: preempt_disable() call (*__mark_call_##name)(format, ## args); preempt_enable_no_resched() 2: is insured because : 1 is part of an inline assembly with rw dependency on __marker_sequencer the call is surrounded by memory barriers. 2 is part of an inline assembly with rw dependency on __marker_sequencer Mathieu * Mathieu Desnoyers (compudj@krystal.dyndns.org) wrote: > +++ b/include/asm-generic/marker.h > @@ -0,0 +1,22 @@ > +/* > + * marker.h > + * > + * Code markup for dynamic and static tracing. Generic header. > + * > + * This file is released under the GPLv2. > + * See the file COPYING for more details. > + */ > + > +#define MARK_CALL(name, format, args...) \ > + do { \ > + static marker_probe_func *__mark_call_##name = \ > + __mark_empty_function; \ > + asm volatile( ".section .markers, \"a\";\n\t" \ > + ".long %1, %2;\n\t" \ > + ".previous;\n\t" : "+m" (__marker_sequencer) : \ > + "m" (__mark_call_##name), \ > + "m" (*format)); \ > + preempt_disable(); \ > + (*__mark_call_##name)(format, ## args); \ > + preempt_enable_no_resched(); \ > + } while(0) > --- /dev/null > +++ b/include/asm-i386/marker.h > @@ -0,0 +1,30 @@ > +/* > + * marker.h > + * > + * Code markup for dynamic and static tracing. i386 architecture optimisations. > + * > + * (C) Copyright 2006 Mathieu Desnoyers > + * > + * This file is released under the GPLv2. > + * See the file COPYING for more details. > + */ > + > +#include > + > +#define ARCH_HAS_MARK_JUMP > + > +/* Note : max 256 bytes between over_label and near_jump */ > +#define MARK_JUMP(name, format, args...) \ > + do { \ > + asm volatile( ".section .markers, \"a\";\n\t" \ > + ".long 0f, 1f, 2f;\n\t" \ > + ".previous;\n\t" \ > + ".align 16;\n\t" \ > + ".byte 0xeb;\n\t" \ > + "0:\n\t" \ > + ".byte 2f-1f;\n\t" \ > + "1:\n\t" \ > + : "+m" (__marker_sequencer) : ); \ > + MARK_CALL(name, format, ## args); \ > + asm volatile ( "2:\n\t" : "+m" (__marker_sequencer) : ); \ > + } while(0) 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/