From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx2.redhat.com ([66.187.237.31]) by bombadil.infradead.org with esmtp (Exim 4.69 #1 (Red Hat Linux)) id 1LPIRu-0006RL-Gy for kexec@lists.infradead.org; Tue, 20 Jan 2009 15:23:33 +0000 Date: Tue, 20 Jan 2009 10:22:56 -0500 From: Vivek Goyal Subject: Re: [PATCH]: add dmesg log symbols to /proc/vmcoreinfo lists Message-ID: <20090120152255.GB5125@redhat.com> References: <20090119212127.GA13157@hmsreliant.think-freely.org> <20090120141551.GA5125@redhat.com> <20090120150958.GB18207@hmsreliant.think-freely.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20090120150958.GB18207@hmsreliant.think-freely.org> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: kexec-bounces@lists.infradead.org Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Neil Horman Cc: hbabu@us.ibm.com, akpm@linux-foundation.org, horms@verge.net.au, kexec@lists.infradead.org, linux-kernel@vger.kernel.org On Tue, Jan 20, 2009 at 10:09:58AM -0500, Neil Horman wrote: > On Tue, Jan 20, 2009 at 09:15:51AM -0500, Vivek Goyal wrote: > > On Mon, Jan 19, 2009 at 04:21:27PM -0500, Neil Horman wrote: > > > Hey all- > > > It would be nice to be able to extract the dmesg log from a vmcore file > > > without needing to keep the debug symbols for the running kernel handy all the > > > time. We have a facility to do this in /proc/vmcore. This patch adds the > > > log_buf and log_end symbols to the vmcoreinfo area so that tools (like > > > makedumpfile) can easily extract the dmesg logs from a vmcore image. > > > > > > > It would be nice to get dmesg log if debug symbols are not around. Can't > > we use System.map for getting symbol addresses? vmcoreinfo had started > > small and seems to be growing now. I am thinking down the line will making > > use of System.map for such cases make sense? > > > > System.map only include exported and public symbols. log_buf and log_end are > static, and not reported in the System.map. Its a nice idea, but not > comprehensive for everything in the kernel. > > > > > > > Will it be an issue if we make log_buf and log_end non static and directly > > access these in kexec.c? > > > I had considered that, but was a bit hesitant to do so, since it exposes the > internal implementation of the dmesg buffer. In the event someone disables > CONFIG_PRINTK, thats just more code we need to ifdef. With this implementation > we just stub out the log_buf_setup function, and let that be that. It seems > more consice to me this way. > Makes sense to me. Acked-by: Vivek Goyal Thanks Vivek _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec