From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750925Ab3FCC6d (ORCPT ); Sun, 2 Jun 2013 22:58:33 -0400 Received: from shards.monkeyblade.net ([149.20.54.216]:36469 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750765Ab3FCC63 (ORCPT ); Sun, 2 Jun 2013 22:58:29 -0400 Date: Sun, 02 Jun 2013 19:58:26 -0700 (PDT) Message-Id: <20130602.195826.721294433730539253.davem@davemloft.net> To: eric.dumazet@gmail.com Cc: klamm@yandex-team.ru, paulmck@linux.vnet.ibm.com, brouer@redhat.com, dipankar@in.ibm.com, zhmurov@yandex-team.ru, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, kuznet@ms2.inr.ac.ru, jmorris@namei.org, yoshfuji@linux-ipv6.org, kaber@trash.net, David.Laight@ACULAB.COM Subject: Re: [PATCH v2] rcu: fix a race in hlist_nulls_for_each_entry_rcu macro From: David Miller In-Reply-To: <1370215895.24311.93.camel@edumazet-glaptop> References: <1369854387.5109.77.camel@edumazet-glaptop> <51A70CF4.1020807@yandex-team.ru> <1370215895.24311.93.camel@edumazet-glaptop> X-Mailer: Mew version 6.5 on Emacs 24.1 / Mule 6.0 (HANACHIRUSATO) 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 From: Eric Dumazet Date: Sun, 02 Jun 2013 16:31:35 -0700 > On Thu, 2013-05-30 at 12:25 +0400, Roman Gushchin wrote: >> On 29.05.2013 23:06, Eric Dumazet wrote: >> > On Wed, 2013-05-29 at 14:09 +0400, Roman Gushchin wrote: >> > >> > True, these lookup functions are usually structured the same around the >> > hlist_nulls_for_each_entry_rcu() loop. >> > >> > A barrier() right before the loop seems to be a benefit, the size of >> > assembly code is reduced by 48 bytes. >> > >> > And its one of the documented way to handle this kind of problems >> > (Documentation/atomic_ops.txt line 114) >> > >> > I guess we should amend this documentation, eventually. >> > >> > Thanks, please add you "Signed-off-by" if you agree with the patch. >> > >> >> Signed-off-by: Roman Gushchin >> >> Many thanks to you, Paul E. McKenney and David Laight for your >> patches, help and participation in this discussion. > > Thanks to you ! > > David, is there any problem with the patch ? > > http://patchwork.ozlabs.org/patch/247360/ says "Not applicable", please > tell me what is needed to get it merged. It's not a networking patch, it's a patch for generic RCU upstream. So it either goes through Paul McKenney, or directly via Linus on linux-kernel.