Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758416Ab0LCHyS (ORCPT ); Fri, 3 Dec 2010 02:54:18 -0500 Received: from serv04.lahn.de ([213.239.197.57]:53123 "EHLO serv04.lahn.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756083Ab0LCHyR (ORCPT ); Fri, 3 Dec 2010 02:54:17 -0500 Date: Fri, 3 Dec 2010 08:53:50 +0100 From: Michael Leun To: Miklos Szeredi Cc: hughd@google.com, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: kernel BUG at mm/truncate.c:475! Message-ID: <20101203085350.55f94057@xenia.leun.net> In-Reply-To: <20101202115722.1c00afd5@xenia.leun.net> References: <20101130194945.58962c44@xenia.leun.net> <20101201124528.6809c539@xenia.leun.net> <20101202084159.6bff7355@xenia.leun.net> <20101202091552.4a63f717@xenia.leun.net> <20101202115722.1c00afd5@xenia.leun.net> Organization: Not Organized X-Mailer: Claws Mail 3.7.6 (GTK+ 2.20.1; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1692 Lines: 54 On Thu, 2 Dec 2010 11:57:22 +0100 Michael Leun wrote: > > Can you please describe in detail the workload that's causing this > > to happen? > > Thats rather complicated, but I'll try. Basically it boils down to: > > unshare -n -m /bin/bash > unionfs -o > cow,suid,allow_other,max_files=65536 /home/netenv/user1-union=RW:/=RO /home/netenv/user1 > mount -n -t proc none /home/netenv/user1/proc mount -n -t sysfs > none /home/netenv/user1/sys mount -n -t devtmpfs > devtmpfs /home/netenv/user1/dev mount -n -t devpts > devpts /home/netenv/user1/dev/pts chroot /home/netenv/user1 /bin/su - > user1 [...] > In some of this setups two or more environments share the same > writable branch, so the files in this environments changed against > real root of the machine are the same, e.g.: > > [...] > unionfs -o > cow,suid,allow_other,max_files=65536 /home/netenv/commondir=RW:/=RO /home/netenv/user1 > [...] > > and another one > > [...] > unionfs -o > cow,suid,allow_other,max_files=65536 /home/netenv/commondir=RW:/=RO /home/netenv/user2 > [...] Additional note: Happens also WITHOUT that "two unionfs mounts use the same branch dir" stuff. Really seems to happen much more often in 2.6.36.1 than in 2.6.36. > I observed that unionfs process takes much more cpu power than usual > before fault happens. This also happens without that "two unionfs mounts use the same branch dir" stuff. -- MfG, Michael Leun -- 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/