From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH 6/13] bridge: Add core IGMP snooping support Date: Wed, 10 Mar 2010 08:35:47 -0800 (PST) Message-ID: <20100310.083547.213194954.davem@davemloft.net> References: <20100310131317.GA6267@linux.vnet.ibm.com> <20100310140729.GA25704@gondor.apana.org.au> <20100310162658.GI6267@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: herbert@gondor.apana.org.au, eric.dumazet@gmail.com, arnd@arndb.de, netdev@vger.kernel.org, shemminger@vyatta.com To: paulmck@linux.vnet.ibm.com Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:35826 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756284Ab0CJQf3 (ORCPT ); Wed, 10 Mar 2010 11:35:29 -0500 In-Reply-To: <20100310162658.GI6267@linux.vnet.ibm.com> Sender: netdev-owner@vger.kernel.org List-ID: From: "Paul E. McKenney" Date: Wed, 10 Mar 2010 08:26:58 -0800 > On Wed, Mar 10, 2010 at 10:07:29PM +0800, Herbert Xu wrote: >> On Wed, Mar 10, 2010 at 05:13:18AM -0800, Paul E. McKenney wrote: >> > >> > If CONFIG_PROVE_RCU is set, rcu_dereference() checks for rcu_read_lock() >> > and rcu_dereference_bh() checks for either rcu_read_lock_bh() or BH >> > being disabled. Yes, this is a bit restrictive, but there are a few too >> > many to check by hand these days. >> >> Fair enough. We should get those fixed then. In fact I reckon >> most of them should be using the BH variant so we might be able >> to kill a few rcu_read_lock's which would be a real gain. > > I have -tip commit a898def29e4119bc01ebe7ca97423181f4c0ea2d that > converts some of the rcu_dereference()s in net/core/filter.c, > net/core/dev.c, net/decnet/dn_route.c, net/packet/af_packet.c, and > net/ipv4/route.c to rcu_dereference_bh(). > > How should we coordinate the removal of the rcu_read_lock() calls? Paul if you want to do this via your tree, feel free.