From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756954AbZEEWxg (ORCPT ); Tue, 5 May 2009 18:53:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753625AbZEEWxO (ORCPT ); Tue, 5 May 2009 18:53:14 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:33766 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753402AbZEEWxN (ORCPT ); Tue, 5 May 2009 18:53:13 -0400 Date: Tue, 5 May 2009 15:49:11 -0700 From: Andrew Morton To: Mike Galbraith Cc: viro@ZenIV.linux.org.uk, knobi@knobisoft.de, rjw@sisk.pl, linux-kernel@vger.kernel.org, tigran@aivazian.fsnet.co.uk Subject: Re: Analyzed/Solved: Booting 2.6.30-rc2-git7 very slow Message-Id: <20090505154911.e0309a4f.akpm@linux-foundation.org> In-Reply-To: <1241014725.15095.19.camel@marge.simson.net> References: <409142.83316.qm@web32605.mail.mud.yahoo.com> <20090428182837.62c51f26.akpm@linux-foundation.org> <1240977096.5478.3.camel@marge.simson.net> <20090429011755.c141c599.akpm@linux-foundation.org> <20090429120827.GI8633@ZenIV.linux.org.uk> <1241014725.15095.19.camel@marge.simson.net> X-Mailer: Sylpheed version 2.2.4 (GTK+ 2.8.20; i486-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 On Wed, 29 Apr 2009 16:18:45 +0200 Mike Galbraith wrote: > On Wed, 2009-04-29 at 13:08 +0100, Al Viro wrote: > > On Wed, Apr 29, 2009 at 01:17:55AM -0700, Andrew Morton wrote: > > > > > > > > Questions remains: was this intentional? It breaks existing userspace and should therefore be considered a regression - right? On the other hand, it will never be a problem for RHEL-4/5 kernels, unless the change in 2.6.29 gets backported. Any ideas? > > > > > > > > > > afaik that was unintentional and was probably a mistake. > > > > > > > > > > I wonder how we did that. > > > > > > > > > > > > > [hotplug]# grep sysfs /proc/mounts > > > > > none /sys sysfs rw,relatime 0 0 > > > > > /sys /sys sysfs rw,relatime 0 0 > > > > > > > > ___(I wonder how the heck that is accomplished) > > > > > > Beats me. I'm not seeing likely changes in fs/proc/base.c or around > > > show_mountinfo(). Maybe sysfs broke in an ingenious way. (hopefully > > > cc's viro). > > > > Er... Somebody mounting sysfs twice? From some init script and from > > /etc/fstab, perhaps? That definitely looks like two mount(2) had to > > have been done to cause that... > > Yeah, but how does one go about doing that? > > Using mount -f, I can convince mount to succeed, but I still have only > one entry in /proc/mounts, despite what my mount binary imagines. > > marge:..sys/vm # grep sysfs /proc/mounts > sysfs /sys sysfs rw,relatime 0 0 > > marge:..sys/vm # mount|grep sysfs > sysfs on /sys type sysfs (rw) > sys on /sys type sysfs (rw) > /sys on /sys type sysfs (rw) > So /proc/mounts is OK and /etc/mtab is wrong? Obvious next step is to strace `mount -f', see what's happening around sys_mount(), please.