From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick McHardy Subject: Re: [PATCH 1/3] net: introduce a list of device addresses dev_addr_list Date: Wed, 15 Apr 2009 12:41:01 +0200 Message-ID: <49E5B9BD.5070204@trash.net> References: <49E5A896.90408@cosmosbay.com> <20090415.023104.82135803.davem@davemloft.net> <49E5B365.2010008@trash.net> <20090415.031510.162624644.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Cc: dada1@cosmosbay.com, jpirko@redhat.com, lizf@cn.fujitsu.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, jgarzik@pobox.com, shemminger@linux-foundation.org, bridge@lists.linux-foundation.org, fubar@us.ibm.com, bonding-devel@lists.sourceforge.net, mschmidt@redhat.com, ivecera@redhat.com To: David Miller Return-path: Received: from stinky.trash.net ([213.144.137.162]:56124 "EHLO stinky.trash.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752600AbZDOKlR (ORCPT ); Wed, 15 Apr 2009 06:41:17 -0400 In-Reply-To: <20090415.031510.162624644.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: David Miller wrote: > From: Patrick McHardy > Date: Wed, 15 Apr 2009 12:13:57 +0200 > >> David Miller wrote: >>> From: Eric Dumazet >>> Date: Wed, 15 Apr 2009 11:27:50 +0200 >>> >>>> Since you obviously need a write lock here to be sure following >>>> can be done by one cpu only. >>>> >>>> You have same problem all over this patch. >>> RTNL semaphore is held across all modification operations. >> If this will also be used for multicast lists, changes can happen >> (IPv6) without the RTNL. > > Indeed, that is true :-/ Herbert (I think) suggested to make address list updates in softirq context a two-step process, where addresses would first be added to a temporary list and the final change would be done in process context while holding the RTNL. Given the complicated mess we currently have, this would be a very worthwhile change IMO.