From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gao feng Subject: Re: [PATCH 1/4] ipv4: Fix pmtu propagating Date: Wed, 19 Oct 2011 17:07:50 +0800 Message-ID: <4E9E9366.1050702@cn.fujitsu.com> References: <20111011110922.GD1830@secunet.com> <20111012.170218.279202034199478303.davem@davemloft.net> <20111013100950.GO1830@secunet.com> <20111013.135808.636341622629050648.davem@davemloft.net> <20111014055406.GP1830@secunet.com> <20111017121805.GR1830@secunet.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: David Miller , netdev@vger.kernel.org To: Steffen Klassert Return-path: Received: from cn.fujitsu.com ([222.73.24.84]:57097 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1752789Ab1JSJHX (ORCPT ); Wed, 19 Oct 2011 05:07:23 -0400 In-Reply-To: <20111017121805.GR1830@secunet.com> Sender: netdev-owner@vger.kernel.org List-ID: 2011.10.17 20:18, Steffen Klassert wrote: > On Fri, Oct 14, 2011 at 07:54:06AM +0200, Steffen Klassert wrote: >> On Thu, Oct 13, 2011 at 01:58:08PM -0400, David Miller wrote: >>> >>> Please find out exactly why dst->obsolete is non-zero on a freshly >>> looked up route. It's unexpected. >> >> Hm, on a slow path route lookup e.g. __mkroute_output() calls >> rt_dst_alloc() which initializes dst->obsolete to -1. > > Just a follow up: > git commit d11a4dc18 (ipv4: check rt_genid in dst_check) > changed the initialization value of dst->obsolete from > 0 to -1. > -- Anybody give any suggestion? Actually,we can't suppose the dst->obsolete is non-zero. maybe we should use both dst->obsolete and rt->rt_peer_genid to decide whether to do dst_check or not?