Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755343AbZDPMYV (ORCPT ); Thu, 16 Apr 2009 08:24:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753507AbZDPMYK (ORCPT ); Thu, 16 Apr 2009 08:24:10 -0400 Received: from sovereign.computergmbh.de ([85.214.69.204]:46054 "EHLO sovereign.computergmbh.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752695AbZDPMYJ (ORCPT ); Thu, 16 Apr 2009 08:24:09 -0400 Date: Thu, 16 Apr 2009 14:24:06 +0200 (CEST) From: Jan Engelhardt To: Patrick McHardy cc: Eric Dumazet , Stephen Hemminger , Jeff Chua , paulmck@linux.vnet.ibm.com, David Miller , paulus@samba.org, mingo@elte.hu, torvalds@linux-foundation.org, laijs@cn.fujitsu.com, 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: <49E720BE.2000200@trash.net> Message-ID: References: <20090411174801.GG6822@linux.vnet.ibm.com> <18913.53699.544083.320542@cargo.ozlabs.ibm.com> <20090412173108.GO6822@linux.vnet.ibm.com> <20090412.181330.23529546.davem@davemloft.net> <20090413040413.GQ6822@linux.vnet.ibm.com> <20090413095309.631cf395@nehalam> <49E48136.5060700@trash.net> <49E49C65.8060808@cosmosbay.com> <20090414074554.7fa73e2f@nehalam> <49E4B0A5.70404@cosmosbay.com> <20090414111716.28585806@nehalam> <49E4E3E8.5090201@cosmosbay.com> <20090414141351.0f63ac98@nehalam> <49E502B5.7070700@cosmosbay.com> <49E5BDF7.8090502@trash.net> <20090415135526.2afc4d18@nehalam> <49E64C91.5020708@cosmosbay.com> <49E720BE.2000200@trash.net> User-Agent: Alpine 2.00 (LSU 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1101 Lines: 27 On Thursday 2009-04-16 14:12, Patrick McHardy wrote: > Jan Engelhardt wrote: >> On Wednesday 2009-04-15 23:07, Eric Dumazet wrote: >>> Stephen Hemminger a écrit : >>>> Looks like there is some recursive path into ip_tables that makes the >>>> per-cpu spinlock break. I get lockup's with KVM networking. >>>> >>>> Suggestions? >>> Well, it seems original patch was not so bad after all >>> >>> http://lists.netfilter.org/pipermail/netfilter-devel/2006-January/023175.html >>> >>> So change per-cpu spinlocks to per-cpu rwlocks >>> and use read_lock() in ipt_do_table() to allow recursion... >>> >> iptables cannot quite recurse into itself due to the comefrom stuff. > > Actually it can by using the REJECT target: Yes, but it has to return an absolute verdict (which REJECT does), so it's not really a recursion, it's more like a goto without return. -- 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/