From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753571AbYDEQlU (ORCPT ); Sat, 5 Apr 2008 12:41:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752527AbYDEQlB (ORCPT ); Sat, 5 Apr 2008 12:41:01 -0400 Received: from nn7.de ([85.214.94.156]:44481 "EHLO nn7.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752515AbYDEQlA convert rfc822-to-8bit (ORCPT ); Sat, 5 Apr 2008 12:41:00 -0400 Subject: Re: 2.6.25-rc8: WARNING: at net/ipv4/tcp_input.c:2173 tcp_mark_head_lost+0x11d/0x150() From: Soeren Sonnenburg To: Ilpo =?ISO-8859-1?Q?J=E4rvinen?= Cc: Linux Kernel , Netdev In-Reply-To: References: <1207199456.7616.3.camel@localhost> <1207230008.4513.14.camel@localhost> Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 8BIT Date: Sat, 05 Apr 2008 18:40:34 +0200 Message-Id: <1207413634.4597.4.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 2.22.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2008-04-04 at 21:51 +0300, Ilpo Järvinen wrote: > On Thu, 3 Apr 2008, Soeren Sonnenburg wrote: > > > On Thu, 2008-04-03 at 16:26 +0300, Ilpo Järvinen wrote: > > > On Thu, 3 Apr 2008, Soeren Sonnenburg wrote: > > > > > > > trying to download things, I am seeing this (ignore the tainted, it is > > > > from madwifi and although the module is loaded the device was never > > > > used) > > > > > > > > Could anyone make sense of this please? > > > > > > ...I'm just trying to find out who and where invariants of the TCP code > > > are broken. These were relatively recently enabled (pre-2.6.24 just didn't > > > care too much). A number of long standing issues plus bugs from my > > > modifications have been fixed because of the more rigid checking :-). > > > > > > > ------------[ cut here ]------------ > > > > WARNING: at net/ipv4/tcp_input.c:2173 tcp_mark_head_lost+0x11d/0x150() > > > > > > > ------------[ cut here ]------------ > > > > WARNING: at net/ipv4/tcp_input.c:1771 tcp_enter_frto+0x267/0x270() > > > > > > > ------------[ cut here ]------------ > > > > WARNING: at net/ipv4/tcp_input.c:2532 tcp_ack+0x1a6f/0x1d60() > > > > > > Can you reproduce it? > > > > Yes, by massively downloading things :-) But I have no real recipe to > > make it easily reproducible... > > Good :-), no need for recipes, just that you can trigger it more often > tha once per month or so :-). I probably couldn't trigger it anyway here > because they're often rather sensitive to network "weather", thus if you > have problems in reproducing, doing tests around the same phase of the > date cycle you saw it the first time might help. > > Here's a debug patch which expensively verifies TCP's state in a number > of places during ACK to find first spot where the actual bug occurs. OK I am getting this now as the first spot: P: 4 L: 2 vs 2 S: 0 vs 3 F: 0 vs 0 w: 4023500226-4023505874 (0) skb 0 f495c180 skb 1 f480a180 skb 2 f4994600 head 3 f495c780 skb 4 f5b32480 TCP wq(s) LL < WARNING: at net/ipv4/tcp_ipv4.c:240 tcp_verify_wq+0x319/0x3c0() another one: WARNING: at net/ipv4/tcp_output.c:1475 __tcp_push_pending_frames+0x70/0x830() P: 4 L: 2 vs 2 S: 0 vs 3 F: 0 vs 0 w: 4023500226-4023505874 (0) skb 0 f495c180 skb 1 f480a180 skb 2 f4994600 head 3 f495c780 skb 4 f5b32480 TCP wq(s) LL < TCP wq(h) +-++< l2 s3 f0 p4 seq: su4023500226 hs241530103 sn4023505874 ------------[ cut here ]------------ WARNING: at net/ipv4/tcp_ipv4.c:240 tcp_verify_wq+0x319/0x3c0() Soeren