From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 16234 invoked by alias); 7 Feb 2011 16:25:50 -0000 Received: (qmail 16215 invoked by uid 22791); 7 Feb 2011 16:25:48 -0000 X-SWARE-Spam-Status: No, hits=-6.8 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_HI,SPF_HELO_PASS,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Mon, 07 Feb 2011 16:25:44 +0000 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id p17GPY5S011258 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Mon, 7 Feb 2011 11:25:35 -0500 Received: from ns3.rdu.redhat.com (ns3.rdu.redhat.com [10.11.255.199]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id p17GPYh2002707; Mon, 7 Feb 2011 11:25:34 -0500 Received: from opsy.redhat.com (ovpn01.gateway.prod.ext.phx2.redhat.com [10.5.9.1]) by ns3.rdu.redhat.com (8.13.8/8.13.8) with ESMTP id p17GPX0u024712; Mon, 7 Feb 2011 11:25:33 -0500 Received: by opsy.redhat.com (Postfix, from userid 500) id 1D457378326; Mon, 7 Feb 2011 09:25:33 -0700 (MST) From: Tom Tromey To: Hui Zhu Cc: linux-kernel@vger.kernel.org, Michael Snyder , Marc Khouzam , Thiago Jung Bauermann , Steven , colyli@gmail.com, Christoph Hellwig , "gdb\@sourceware.org" Subject: Re: [PATCH] Linux Kernel GDB tracepoint module 2011-02-05 References: Date: Mon, 07 Feb 2011 16:25:00 -0000 In-Reply-To: (Hui Zhu's message of "Sun, 6 Feb 2011 00:37:37 +0800") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Mailing-List: contact gdb-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sourceware.org X-SW-Source: 2011-02/txt/msg00040.txt.bz2 >>>>> ">" == Hui Zhu writes: >> We have trouble for this printf is GDB is still not accept the patch >> that make tracepoint support printf, So if you want use it, you need >> patch the patch in >> http://sourceware.org/ml/gdb-patches/2011-02/msg00063.html and build >> your GDB with yourself. Thanks, I think this example was helpful. >> Sometimes, GDB will output some value like: >> inode has been optimized out of existence. >> res has been optimized out of existence. >> That is because value of inode and res is optimized. Linux Kernel is >> built with -O2 so you will get this trouble sometimes. If you do not >> care about the speed when you debug the Kernel, you can use the patch >> for Linux Kernel in I am curious to know what version of GCC you are using. IME, the VTA patches really helped with this problem a lot -- though not completely. If you are not using a VTA-enabled GCC, you should. And if you are, I think bug reports about values that are still optimized out would be useful. Tom