Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756910Ab2EWHln (ORCPT ); Wed, 23 May 2012 03:41:43 -0400 Received: from mail-ey0-f174.google.com ([209.85.215.174]:57292 "EHLO mail-ey0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755623Ab2EWHlm (ORCPT ); Wed, 23 May 2012 03:41:42 -0400 Subject: Re: [PATCH] ipv4: fix the rcu race between free_fib_info and ip_route_output_slow From: Eric Dumazet To: Yanmin Zhang Cc: David Miller , kunx.jiang@intel.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <1337758775.3361.2056.camel@edumazet-glaptop> References: <4FBB6105.2060808@intel.com> <20120522.151554.106838106733194160.davem@davemloft.net> <1337742123.14538.175.camel@ymzhang.sh.intel.com> <20120522.232310.911242148705021745.davem@davemloft.net> <1337747829.3361.1599.camel@edumazet-glaptop> <1337748897.14538.184.camel@ymzhang.sh.intel.com> <1337749339.3361.1655.camel@edumazet-glaptop> <1337753757.14538.190.camel@ymzhang.sh.intel.com> <1337754459.3361.1850.camel@edumazet-glaptop> <1337755623.14538.194.camel@ymzhang.sh.intel.com> <1337756138.3361.1922.camel@edumazet-glaptop> <1337757238.3361.1965.camel@edumazet-glaptop> <1337757862.14538.199.camel@ymzhang.sh.intel.com> <1337758775.3361.2056.camel@edumazet-glaptop> Content-Type: text/plain; charset="UTF-8" Date: Wed, 23 May 2012 09:41:34 +0200 Message-ID: <1337758894.3361.2064.camel@edumazet-glaptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 582 Lines: 16 On Wed, 2012-05-23 at 09:39 +0200, Eric Dumazet wrote: > spinlock is needed mainly because of ip_fib_check_default(), but this > could be changed to use RCU as well. > > (readers use RCU, writers already hold RTNL -> no more fib_info_lock ) Since its not a fast path and hash table can be resized, its probably not worth the pain. -- 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/