Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932203AbWIVCGb (ORCPT ); Thu, 21 Sep 2006 22:06:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932204AbWIVCGb (ORCPT ); Thu, 21 Sep 2006 22:06:31 -0400 Received: from tomts13.bellnexxia.net ([209.226.175.34]:9864 "EHLO tomts13-srv.bellnexxia.net") by vger.kernel.org with ESMTP id S932203AbWIVCGa (ORCPT ); Thu, 21 Sep 2006 22:06:30 -0400 Date: Thu, 21 Sep 2006 22:01:19 -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 Subject: Re: [PATCH] Linux Kernel Markers 0.7 for 2.6.17 (with type checking!) Message-ID: <20060922020119.GA28712@Krystal> References: <20060921232024.GA16155@Krystal> <451331A1.3020601@goop.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline In-Reply-To: <451331A1.3020601@goop.org> X-Editor: vi X-Info: http://krystal.dyndns.org:8080 X-Operating-System: Linux/2.4.32-grsec (i686) X-Uptime: 21:17:21 up 29 days, 22:26, 1 user, load average: 0.12, 0.14, 0.15 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: 1648 Lines: 51 * Jeremy Fitzhardinge (jeremy@goop.org) wrote: > Mathieu Desnoyers wrote: > >+#ifdef CONFIG_MARK_SYMBOL > >+#define MARK_SYM(name) \ > >+ do { \ > >+ __label__ here; \ > >+ here: asm volatile \ > >+ (MARK_KPROBE_PREFIX#name " = %0" : : "m" (*&&here)); > >\ > >+ } while(0) > >+#else > >+#define MARK_SYM(name) > >+#endif > > BTW, this won't work if you put the MARK_SYM in a loop which gcc > unrolls; you'll only get the mark in the last unrolled iteration > (because the symbol assignments will override each other). > > Do make this work properly, you really need to put the mark entries into > a separate section, so that if gcc duplicates the code, you get > duplicated markers too. > Good point, I will change it to : #define MARK_SYM(name) \ do { \ __label__ here; \ volatile static void *__mark_kprobe_##name \ asm (MARK_CALL_PREFIX#name) \ __attribute__((unused)) = &&here; \ here: \ do { } while(0); \ } while(0) Which fixes the problem. Some tests showed me that the compiler does not unroll an otherwise unrolled loop when this specific macro is called. (test done with -funroll-all-loops). Regards, 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/