From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jon Masters Subject: Re: [PATCH] bridge: Module use count must be updated as bridges are created/destroyed Date: Fri, 29 Apr 2011 12:20:01 -0400 Message-ID: <1304094001.11627.388.camel@constitution.bos.jonmasters.org> References: <4DBA87B6020000780003ED74@vpn.id2.novell.com> <20110429.011051.183061494.davem@davemloft.net> <4DBA937F020000780003ED96@vpn.id2.novell.com> <20110429.014445.39196872.davem@davemloft.net> <4DBA9C71020000780003EDBE@vpn.id2.novell.com> <4DBA9C23.2000408@suse.cz> <1304093116.11627.386.camel@constitution.bos.jonmasters.org> <4DBAFE45020000780003EEE6@vpn.id2.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: David Miller , Jon Masters , shemminger@linux-foundation.org, bridge@lists.linux-foundation.org, jeffm@suse.com, Michal Marek , netdev@vger.kernel.org To: Jan Beulich Return-path: Received: from edison.jonmasters.org ([173.255.233.168]:52138 "EHLO edison.jonmasters.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759849Ab1D2QQY (ORCPT ); Fri, 29 Apr 2011 12:16:24 -0400 In-Reply-To: <4DBAFE45020000780003EEE6@vpn.id2.novell.com> Sender: netdev-owner@vger.kernel.org List-ID: On Fri, 2011-04-29 at 17:07 +0100, Jan Beulich wrote: > >>> On 29.04.11 at 18:05, Jon Masters wrote: > > On Fri, 2011-04-29 at 13:08 +0200, Michal Marek wrote: > >> On 29.4.2011 11:09, Jan Beulich wrote: > >> >>>> On 29.04.11 at 10:44, David Miller wrote: > > > >> >> Nothing on the system should be hitting modules with unload requests > >> >> unless the user explicitly asked for that specific module to be > >> >> unloaded. At least not by default. > >> >> > >> >> So the me the problem is perhaps that "modprobe -r" does this auto > >> >> dependency unloading thing by default. > >> >> > >> >> When we first fixed network device drivers so that they now properly > >> >> always run with no module refcount at all, people complained because > >> >> there were some distributions that ran some daemon that periodically > >> >> looked for "unreferenced" modules and "helped" the user by > >> >> automatically unloaded them. > >> >> > >> >> We killed that foolish daemon, and we can fix "modprobe -r" too. > >> > > >> > Michal - aren't you the modutils maintainer? > >> > >> That would be Jon (CC added). > > > > Thanks. So the specific feature you mention was added precisely because > > some folks wanted to clean up ununsed modules by removing all of their > > dependencies. Since I've not been on this thread until now, can you let > > me know what precisely you need, and why? We can make the unloading of > > unused modules configurable, but it sounds like you're saying even that > > isn't good enough. What actually happens, what's the bug experience? > > The problem observed was that unloading (via modprobe -r) > ebtable_broute.ko, bridge.ko was also unloaded, causing all > bridged networking to stop functioning on a machine. Ah, right...ouch. That would be a "little" problem. Short of having an exclusion list and all that nonsense, probably best to start with either removing the unload logic or making it globally configurable. Thanks. Jon.