From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]) by casper.infradead.org with esmtp (Exim 4.69 #1 (Red Hat Linux)) id 1MxiXF-00081i-Qd for kexec@lists.infradead.org; Tue, 13 Oct 2009 14:39:40 +0000 Date: Tue, 13 Oct 2009 10:39:21 -0400 (EDT) From: Dave Anderson Message-ID: <356335727.118701255444761636.JavaMail.root@zmail05.collab.prod.int.phx2.redhat.com> In-Reply-To: <1053635400.117951255444447388.JavaMail.root@zmail05.collab.prod.int.phx2.redhat.com> Subject: Re: VMCore from makedumpfile -d 2 Failed to be Read by Crash MIME-Version: 1.0 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: oomichi@mxs.nes.nec.co.jp, tachibana@mxm.nes.nec.co.jp, kexec@lists.infradead.org, CAI Qian ----- "Dave Anderson" wrote: > ----- "Neil Horman" wrote: > > > On Sat, Oct 10, 2009 at 10:56:32AM +0800, CAI Qian wrote: > > > Hallo! > > > > > > The crash utility failed to initialize when read the VMCore from > > > makedumpfile -d 2. > > > > > > # crash -d 7 vmlinux vmcore.2 > > > > > > > > > GNU_GET_DATATYPE[runqueue]: returned via gdb_error_hook (1 buffer i use) > > > GNU_GET_DATATYPE[runqueue]: returned via gdb_error_hook (1 buffer in use) > > > GNU_GET_DATATYPE[prio_array]: returned via gdb_error_hook (1 buffer in use) > > > GNU_GET_DATATYPE[prio_array]: returned via gdb_error_hook (1 buffer in use) > > > GNU_GET_DATATYPE[prio_array]: returned via gdb_error_hook (1 buffer in use) > > > > > > > > > > > > crash: page excluded: kernel virtual address: ffffffff818d92f8 type: "cpu number (per_cpu)" > > -d 2 is exclude cached pages, I don't rightly see how any of these data structures > > can be in pagecache. Not sure if that means that makedumpfile filtered them > > inappropriately, or if crash is looking for them in the wrong place. > > > > Neil > > Given that the full vmcore shows that there are 2 cpus, and that the > failure above is on an attempt to read/verify a 3rd cpu, it's pretty > clear that this is a crash bug. There have been a few of these type > of bugs that have recently been discovered due to the movement of the > the x8664_pda data structures to per-cpu data variables in 2.6.30. > Unfortunately, the x86_64_per_cpu_init() is trying to figure out > how many cpus are there, and it's currently doing a "read-and-verify" > kind of thing, but will need to be changed to recognize a readmem failure > as the end of the line. > > I'll be back on Tuesday -- Cai, can you contact me offline and > make the vmcore/vmlinux pair available? This will be fixed in the next upstream crash utility release. In the meantime, "page excluded" errors can be worked around by using the --zero_excluded command line option, as in: # crash --zero_excluded vmlinux vmcore.2 Dave _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec