Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753557Ab1BGQZv (ORCPT ); Mon, 7 Feb 2011 11:25:51 -0500 Received: from mx1.redhat.com ([209.132.183.28]:54290 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751318Ab1BGQZu (ORCPT ); Mon, 7 Feb 2011 11:25:50 -0500 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: X-Attribution: Tom Date: Mon, 07 Feb 2011 09:25:33 -0700 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 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1278 Lines: 30 >>>>> ">" == 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 -- 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/