From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932954Ab1FAASS (ORCPT ); Tue, 31 May 2011 20:18:18 -0400 Received: from fnarfbargle.com ([93.93.131.224]:52482 "EHLO fnarfbargle.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1758192Ab1FAASR (ORCPT ); Tue, 31 May 2011 20:18:17 -0400 Message-ID: <4DE5853E.8040106@fnarfbargle.com> Date: Wed, 01 Jun 2011 08:18:06 +0800 From: Brad Campbell User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2.17) Gecko/20110424 Lightning/1.0b2 Thunderbird/3.1.10 MIME-Version: 1.0 To: Hugh Dickins CC: Borislav Petkov , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-mm , Andrea Arcangeli , Izik Eidus Subject: Re: KVM induced panic on 2.6.38[2367] & 2.6.39 References: <4DE44333.9000903@fnarfbargle.com> <20110531054729.GA16852@liondog.tnic> <4DE4B432.1090203@fnarfbargle.com> <20110531103808.GA6915@eferding.osrc.amd.com> <4DE4FA2B.2050504@fnarfbargle.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/06/11 06:31, Hugh Dickins wrote: > > Brad, my suspicion is that in each case the top 16 bits of RDX have been > mysteriously corrupted from ffff to 0000, causing the general protection > faults. I don't understand what that has to do with KSM. No, nor do I. The panic I reproduced with KSM off was in a completely unrelated code path. To be honest I would not be surprised if it turns out I have dodgy RAM, although it has passed multiple memtests and I've tried clocking it down. Just a gut feeling. > But it's only a suspicion, because I can't make sense of the "Code:" > lines in your traces, they have more than the expected 64 bytes, and > only one of them has a ">" (with no"<") to mark faulting instruction. Yeah, with hindsight I must have removed them when I re-formatted the code from the oops. Each byte was one line in the syslog so there was a lot of deleting to get it to a postable format. > I did try compiling the 2.6.39 kernel from your config, but of course > we have different compilers, so although I got close, it wasn't exact. > > Would you mind mailing me privately (it's about 73MB) the "objdump -trd" > output for your original vmlinux (with KSM on)? (Those -trd options are > the ones I'm used to typing, I bet not they're not all relevant.) > > Of course, it's only a tiny fraction of that output that I need, > might be better to cut it down to remove_rmap_item_from_tree and > dup_fd and ksm_scan_thread, if you have the time to do so. Ok, so since my initial posting I've figured out how to get a clean oops out of netconsole, so tonight (after 9PM GMT+8) I'll reproduce the oops a couple of times. What about I upload the oops, plus the vmlinux, plus .config and System.map to a server with a fat pipe and give you a link to it? At least I can reproduce it quickly and easily. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brad Campbell Subject: Re: KVM induced panic on 2.6.38[2367] & 2.6.39 Date: Wed, 01 Jun 2011 08:18:06 +0800 Message-ID: <4DE5853E.8040106@fnarfbargle.com> References: <4DE44333.9000903@fnarfbargle.com> <20110531054729.GA16852@liondog.tnic> <4DE4B432.1090203@fnarfbargle.com> <20110531103808.GA6915@eferding.osrc.amd.com> <4DE4FA2B.2050504@fnarfbargle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Borislav Petkov , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-mm , Andrea Arcangeli , Izik Eidus To: Hugh Dickins Return-path: In-Reply-To: Sender: owner-linux-mm@kvack.org List-Id: kvm.vger.kernel.org On 01/06/11 06:31, Hugh Dickins wrote: > > Brad, my suspicion is that in each case the top 16 bits of RDX have been > mysteriously corrupted from ffff to 0000, causing the general protection > faults. I don't understand what that has to do with KSM. No, nor do I. The panic I reproduced with KSM off was in a completely unrelated code path. To be honest I would not be surprised if it turns out I have dodgy RAM, although it has passed multiple memtests and I've tried clocking it down. Just a gut feeling. > But it's only a suspicion, because I can't make sense of the "Code:" > lines in your traces, they have more than the expected 64 bytes, and > only one of them has a ">" (with no"<") to mark faulting instruction. Yeah, with hindsight I must have removed them when I re-formatted the code from the oops. Each byte was one line in the syslog so there was a lot of deleting to get it to a postable format. > I did try compiling the 2.6.39 kernel from your config, but of course > we have different compilers, so although I got close, it wasn't exact. > > Would you mind mailing me privately (it's about 73MB) the "objdump -trd" > output for your original vmlinux (with KSM on)? (Those -trd options are > the ones I'm used to typing, I bet not they're not all relevant.) > > Of course, it's only a tiny fraction of that output that I need, > might be better to cut it down to remove_rmap_item_from_tree and > dup_fd and ksm_scan_thread, if you have the time to do so. Ok, so since my initial posting I've figured out how to get a clean oops out of netconsole, so tonight (after 9PM GMT+8) I'll reproduce the oops a couple of times. What about I upload the oops, plus the vmlinux, plus .config and System.map to a server with a fat pipe and give you a link to it? At least I can reproduce it quickly and easily. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org