Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932076AbWITRVK (ORCPT ); Wed, 20 Sep 2006 13:21:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932081AbWITRVK (ORCPT ); Wed, 20 Sep 2006 13:21:10 -0400 Received: from tomts25-srv.bellnexxia.net ([209.226.175.188]:61124 "EHLO tomts25-srv.bellnexxia.net") by vger.kernel.org with ESMTP id S932077AbWITRVI (ORCPT ); Wed, 20 Sep 2006 13:21:08 -0400 Date: Wed, 20 Sep 2006 13:15:54 -0400 From: Mathieu Desnoyers To: Karim Yaghmour Cc: Masami Hiramatsu , Martin Bligh , prasanna@in.ibm.com, Andrew Morton , "Frank Ch. Eigler" , 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 Message-ID: <20060920171554.GB18333@Krystal> References: <4510151B.5070304@google.com> <20060919093935.4ddcefc3.akpm@osdl.org> <45101DBA.7000901@google.com> <20060919063821.GB23836@in.ibm.com> <45102641.7000101@google.com> <20060919070516.GD23836@in.ibm.com> <451030A6.6040801@google.com> <45105B5E.9080107@opersys.com> <451141B1.40803@hitachi.com> <451178B0.9030205@opersys.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline In-Reply-To: <451178B0.9030205@opersys.com> X-Editor: vi X-Info: http://krystal.dyndns.org:8080 X-Operating-System: Linux/2.4.32-grsec (i686) X-Uptime: 13:14:44 up 28 days, 14:23, 5 users, load average: 0.47, 0.47, 0.40 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: 1345 Lines: 36 * Karim Yaghmour (karim@opersys.com) wrote: > > Masami Hiramatsu wrote: > > This method is very similar to the djprobe. > > And I had gotten the same idea to support preemptive kernel. > ... > > This means the below code, doesn't this? > > --- > > jmp 1f /* short jump consumes 2 bytes */ > > nop > > nop > > nop > > 1: > > Actually this is slightly different (and requires more support > on behalf of the underlying mechanism then what I was suggesting.) > Basically, as was discussed elsewhere, there is some complex > mechanisms required for taking care of the case where you got > an interrupt at, say, the second or third nop. With the > mechanism I'm suggesting (replacing a 5 byte jmp with a 5 byte > jmp), the underlying mechanics do not require having to take > care of the above-mentioned case. > Karim, the jmp already there targets the end of the region : no possible executioni of the three following nops. Clever :) 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/