From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Frederic Sowa Subject: Re: IPv6 path MTU discovery broken Date: Sun, 13 Oct 2013 19:56:19 +0200 Message-ID: <20131013175619.GC14021@order.stressinduktion.org> References: <20130927201420.GB12043@sesse.net> <20130928203318.GC23654@order.stressinduktion.org> <20131006120612.GA27852@sesse.net> <20131007015252.GE9295@order.stressinduktion.org> <20131007030910.GG9295@order.stressinduktion.org> <20131013104021.GB24967@sesse.net> <1381683063.3392.46.camel@edumazet-glaptop.roam.corp.google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Cc: "Steinar H. Gunderson" , netdev@vger.kernel.org, edumazet@google.com, fan.du@windriver.com To: Eric Dumazet Return-path: Received: from order.stressinduktion.org ([87.106.68.36]:60045 "EHLO order.stressinduktion.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754917Ab3JMR4U (ORCPT ); Sun, 13 Oct 2013 13:56:20 -0400 Content-Disposition: inline In-Reply-To: <1381683063.3392.46.camel@edumazet-glaptop.roam.corp.google.com> Sender: netdev-owner@vger.kernel.org List-ID: On Sun, Oct 13, 2013 at 09:51:03AM -0700, Eric Dumazet wrote: > On Sun, 2013-10-13 at 12:40 +0200, Steinar H. Gunderson wrote: > > [resending with proper quoting and cc] > > > > On Mon, Oct 07, 2013 at 05:09:10AM +0200, Hannes Frederic Sowa wrote: > > > Could you try to check (with e.g. nstat) if any of the following counters > > > change if the icmp messages hit the host? > > > > > > TcpExtOutOfWindowIcmps > > > Icmp6InErrors > > > TcpExtTCPMinTTLDrop > > > TcpExtListenDrops > > > > Hi, > > > > I am now seeing the same problem against a 3.9.0 machine (that I've never had > > problems with before). I looked through the four nstat counters, and none of > > them are increasing. Here's /proc/net/ipv6_route from the server while it's > > going on; the client is 2001:67c:a4:1:71f9:c84b:8b2a:c65b (second line) and > > the server is 2001:67c:29f4::2007. > > I am not sure, but the skb_is_gso() checks seem too lazy. > > Why don't we check that gso_size+headers is below mtu, I dont know. Was this intended for the UFO gso thread? ;)