From patchwork Wed Jun 24 11:44:44 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jesper Dangaard Brouer X-Patchwork-Id: 29119 Return-Path: X-Original-To: patchwork-incoming@bilbo.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from ozlabs.org (ozlabs.org [203.10.76.45]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mx.ozlabs.org", Issuer "CA Cert Signing Authority" (verified OK)) by bilbo.ozlabs.org (Postfix) with ESMTPS id 33813B7091 for ; Wed, 24 Jun 2009 21:45:42 +1000 (EST) Received: by ozlabs.org (Postfix) id 28191DDD04; Wed, 24 Jun 2009 21:45:42 +1000 (EST) Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by ozlabs.org (Postfix) with ESMTP id A86D2DDD01 for ; Wed, 24 Jun 2009 21:45:41 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757418AbZFXLoq (ORCPT ); Wed, 24 Jun 2009 07:44:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752498AbZFXLop (ORCPT ); Wed, 24 Jun 2009 07:44:45 -0400 Received: from lanfw001a.cxnet.dk ([87.72.215.196]:47724 "EHLO lanfw001a.cxnet.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753382AbZFXLon (ORCPT ); Wed, 24 Jun 2009 07:44:43 -0400 Received: from comxexch02.comx.local (unknown [172.31.1.117]) by lanfw001a.cxnet.dk (Postfix) with ESMTP id 59D70163822; Wed, 24 Jun 2009 13:44:45 +0200 (CEST) Received: from hawk.comx.local ([172.31.4.93]) by comxexch02.comx.local with Microsoft SMTPSVC(6.0.3790.3959); Wed, 24 Jun 2009 13:44:45 +0200 Subject: Re: [PATCH 07/10] decnet: Use rcu_barrier() on module unload. From: Jesper Dangaard Brouer To: Chrissie Caulfield Cc: "David S. Miller" , "Paul E. McKenney" , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, dougthompson@xmission.com, bluesmoke-devel@lists.sourceforge.net, axboe@kernel.dk, Patrick McHardy , Trond.Myklebust@netapp.com, linux-wireless@vger.kernel.org, johannes@sipsolutions.net, yoshfuji@linux-ipv6.org, shemminger@linux-foundation.org, linux-nfs@vger.kernel.org, bfields@fieldses.org, neilb@suse.de, linux-ext4@vger.kernel.org, tytso@mit.edu, adilger@sun.com, netfilter-devel@vger.kernel.org In-Reply-To: <4A41C67E.8070301@googlemail.com> References: <20090623150330.22490.87327.stgit@localhost> <20090623150429.22490.15113.stgit@localhost> <4A41C67E.8070301@googlemail.com> Organization: ComX Networks A/S Date: Wed, 24 Jun 2009 13:44:44 +0200 Message-Id: <1245843884.6695.54.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.6.3 X-OriginalArrivalTime: 24 Jun 2009 11:44:45.0104 (UTC) FILETIME=[2B6A9300:01C9F4C1] Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, 2009-06-24 at 07:23 +0100, Chrissie Caulfield wrote: > The issues with DECnet module unloading are a little more than just an > RCU leak I think! > > Though that area does need reviewing ... when I get some time. Fine. Now you have read my comment in the code, then there is a updated patch below. Will you ack-that? diff --git a/net/decnet/af_decnet.c b/net/decnet/af_decnet.c index d351b8d..bff12da 100644 --- a/net/decnet/af_decnet.c +++ b/net/decnet/af_decnet.c @@ -2393,6 +2393,10 @@ module_init(decnet_init); * Prevent DECnet module unloading until its fixed properly. * Requires an audit of the code to check for memory leaks and * initialisation problems etc. + * + * hawk@comx.dk 2009-06-19: + * I have added a rcu_barrier() which should plug some of your + * module unload issues. Maintainers please try it out... */ #if 0 static void __exit decnet_exit(void) @@ -2413,6 +2417,8 @@ static void __exit decnet_exit(void) proc_net_remove(&init_net, "decnet"); proto_unregister(&dn_proto); + + rcu_barrier_bh(); /* Wait for completion of call_rcu_bh()'s */ } module_exit(decnet_exit); #endif