From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754598AbZBIJe2 (ORCPT ); Mon, 9 Feb 2009 04:34:28 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752617AbZBIJeU (ORCPT ); Mon, 9 Feb 2009 04:34:20 -0500 Received: from zeniv.linux.org.uk ([195.92.253.2]:52414 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751791AbZBIJeT (ORCPT ); Mon, 9 Feb 2009 04:34:19 -0500 Date: Mon, 9 Feb 2009 09:34:14 +0000 From: Al Viro To: Andrew Morton Cc: Li Zefan , LKML , Paul Menage , containers@lists.osdl.org, Arjan van de Ven Subject: Re: [cgroup or VFS ?] WARNING: at fs/namespace.c:636 mntput_no_expire+0xac/0xf2() Message-ID: <20090209093414.GU28946@ZenIV.linux.org.uk> References: <49617D35.4040805@cn.fujitsu.com> <20090209004046.3ce1dde0.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090209004046.3ce1dde0.akpm@linux-foundation.org> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 09, 2009 at 12:40:46AM -0800, Andrew Morton wrote: > > Thread 1: > > for ((; ;)) > > { > > mount -t cgroup -o cpuset xxx /mnt > /dev/null 2>&1 > > mkdir /mnt/0 > /dev/null 2>&1 > > rmdir /mnt/0 > /dev/null 2>&1 > > umount /mnt > /dev/null 2>&1 > > } > > > > Thread 2: > > { > > mount -t cpuset xxx /mnt > /dev/null 2>&1 > > umount /mnt > /dev/null 2>&1 > > } How cute... Same mountpoint in both, so these mount(2) will sometimes fail (cgroup picks the same sb on the same options, AFAICS) and fail silently due to these redirects... That's a lovely way to stress-test a large part of ro-bind stuff *and* umount()-related code. Could you do C equivalent of the above (just the same syscalls in loop, nothing fancier) and do time-stamped strace?