Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751115AbWITLAS (ORCPT ); Wed, 20 Sep 2006 07:00:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751116AbWITLAS (ORCPT ); Wed, 20 Sep 2006 07:00:18 -0400 Received: from mail4.hitachi.co.jp ([133.145.228.5]:37562 "EHLO mail4.hitachi.co.jp") by vger.kernel.org with ESMTP id S1751115AbWITLAP (ORCPT ); Wed, 20 Sep 2006 07:00:15 -0400 Message-ID: <45111F37.2060607@hitachi.com> Date: Wed, 20 Sep 2006 20:00:07 +0900 From: Masami Hiramatsu Organization: Systems Development Lab., Hitachi, Ltd., Japan User-Agent: Thunderbird 1.5.0.7 (Windows/20060909) MIME-Version: 1.0 To: prasanna@in.ibm.com Cc: Martin Bligh , Vara Prasad , Andrew Morton , "Frank Ch. Eigler" , Ingo Molnar , Mathieu Desnoyers , 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 References: <20060919081124.GA30394@elte.hu> <451008AC.6030006@google.com> <20060919154612.GU3951@redhat.com> <4510151B.5070304@google.com> <20060919093935.4ddcefc3.akpm@osdl.org> <45101DBA.7000901@google.com> <20060919063821.GB23836@in.ibm.com> <45102641.7000101@google.com> <4510413F.2030200@us.ibm.com> <45104468.50106@google.com> <20060919093056.GA21618@in.ibm.com> In-Reply-To: <20060919093056.GA21618@in.ibm.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1114 Lines: 31 Hi, S. P. Prasanna wrote: > Some more coplicated method. > How about inserting a (instruction size) number of breakpoints and > wait untill all the threads gets scheduled atleast once (so that > threads would hit the breakpoint, if their IPs are in the middle of > instruction we want to replace with jump) and then replace with > jump instruction. I think there is no need to insert so many breakpoints. Instead of that, you merely wait that all the threads which are running on each processors at that time gets scheduled, if the kernel is *NOT* preemptive. If the kernel is preemptive, some threads might sleep on the target address. In this case, we can use freeze_processes() to ensure safety. This idea was proposed by Ingo. Thanks, -- Masami HIRAMATSU 2nd Research Dept. Hitachi, Ltd., Systems Development Laboratory E-mail: masami.hiramatsu.pt@hitachi.com - 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/