Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756396AbZDPAUl (ORCPT ); Wed, 15 Apr 2009 20:20:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756910AbZDPAUR (ORCPT ); Wed, 15 Apr 2009 20:20:17 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:48829 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754379AbZDPAUO (ORCPT ); Wed, 15 Apr 2009 20:20:14 -0400 Date: Wed, 15 Apr 2009 17:10:19 -0700 (PDT) From: Linus Torvalds X-X-Sender: torvalds@localhost.localdomain To: Stephen Hemminger cc: David Miller , dada1@cosmosbay.com, kaber@trash.net, jeff.chua.linux@gmail.com, paulmck@linux.vnet.ibm.com, paulus@samba.org, mingo@elte.hu, laijs@cn.fujitsu.com, jengelh@medozas.de, r000n@r000n.net, linux-kernel@vger.kernel.org, netfilter-devel@vger.kernel.org, netdev@vger.kernel.org, benh@kernel.crashing.org Subject: Re: [PATCH] netfilter: use per-cpu spinlock rather than RCU (v3) In-Reply-To: <20090415170111.6e1ca264@nehalam> Message-ID: References: <49E5BDF7.8090502@trash.net> <20090415135526.2afc4d18@nehalam> <49E64C91.5020708@cosmosbay.com> <20090415.164811.19905145.davem@davemloft.net> <20090415170111.6e1ca264@nehalam> User-Agent: Alpine 2.00 (LFD 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 820 Lines: 20 On Wed, 15 Apr 2009, Stephen Hemminger wrote: > > The counters are the bigger problem, otherwise we could just free table > info via rcu. Do we really have to support: replace where the counter > values coming out to user space are always exactly accurate, or is it > allowed to replace a rule and maybe lose some counter ticks (worst case > NCPU-1). Why not just read the counters fromt he old one at RCU free time (they are guaranteed to be stable at that point, since we're all done with those entries), and apply them at that point to the current setup? Linus -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/