From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 30 Aug 2001 14:10:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 30 Aug 2001 14:10:11 -0400 Received: from mailhost.nmt.edu ([129.138.4.52]:43533 "EHLO mailhost.nmt.edu") by vger.kernel.org with ESMTP id ; Thu, 30 Aug 2001 14:10:08 -0400 Date: Thu, 30 Aug 2001 12:10:25 -0600 From: Val Henson To: kuznet@ms2.inr.ac.ru Cc: davem@redhat.com, linux-kernel@vger.kernel.org Subject: Lost TCP retransmission timer (was Re: tcp connection hangs on connect) Message-ID: <20010830121025.A15880@boardwalk> In-Reply-To: <20010829195259.B11544@boardwalk> <200108301621.UAA05134@ms2.inr.ac.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <200108301621.UAA05134@ms2.inr.ac.ru>; from kuznet@ms2.inr.ac.ru on Thu, Aug 30, 2001 at 08:21:16PM +0400 Favorite-Color: Polka dot Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 30, 2001 at 08:21:16PM +0400, kuznet@ms2.inr.ac.ru wrote: > > Your hopes were groundless. > Actually, you could change subject, this apparently has nothing > to do with your problem and this is misleading. You're right. I thought the subject was "tcp connection hangs." :) > I have no idea what happens in your case, apparently, retransmission > timer is lost on sender, which is absolutely impossible. :-) > Well, send me cat of /proc/tcp after the stall happened. At least one of the tcpdumps I took showed at least one successful retransmission before the failure. Here's /proc/tcp at 1 second intervals, starting just before the connection starts and ending after I kill it. It looks to me like the timer is going off but the segment isn't getting transmitted. sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode 0: 00000000:0016 00000000:0000 0A 00000000:00000000 00:00000000 00000000 0 0 773 1 c05c0360 300 0 0 2 -1 sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode 0: 00000000:0016 00000000:0000 0A 00000000:00000000 00:00000000 00000000 0 0 773 1 c05c0360 300 0 0 2 -1 1: C6116429:0016 C611642A:046B 01 00000000:00000000 02:000AFC42 00000000 0 0 1502 3 c05c0040 21 4 5 2 -1 sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode 0: 00000000:0016 00000000:0000 0A 00000000:00000000 00:00000000 00000000 0 0 773 1 c05c0360 300 0 0 2 -1 1: C6116429:0016 C611642A:046B 01 00000000:00000000 02:000AFBDD 00000000 0 0 1502 2 c05c0040 21 4 5 2 -1 sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode 0: 00000000:0016 00000000:0000 0A 00000000:00000000 00:00000000 00000000 0 0 773 1 c05c0360 300 0 0 2 -1 1: C6116429:0016 C611642A:046B 01 00003890:00000000 01:00000011 00000000 0 0 1502 9 c05c0040 21 4 1 2 2 sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode 0: 00000000:0016 00000000:0000 0A 00000000:00000000 00:00000000 00000000 0 0 773 1 c05c0360 300 0 0 2 -1 1: C6116429:0016 C611642A:046B 01 000032E8:00000000 01:00000007 00000001 0 0 1502 15 c05c0040 46 4 1 1 2 sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode 0: 00000000:0016 00000000:0000 0A 00000000:00000000 00:00000000 00000000 0 0 773 1 c05c0360 300 0 0 2 -1 1: C6116429:0016 C611642A:046B 01 000032E8:00000000 01:000000B5 00000003 0 0 1502 15 c05c0040 184 4 1 1 2 sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode 0: 00000000:0016 00000000:0000 0A 00000000:00000000 00:00000000 00000000 0 0 773 1 c05c0360 300 0 0 2 -1 1: C6116429:0016 C611642A:046B 01 000032E8:00000000 01:0000004F 00000003 0 0 1502 15 c05c0040 184 4 1 1 2 sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode 0: 00000000:0016 00000000:0000 0A 00000000:00000000 00:00000000 00000000 0 0 773 1 c05c0360 300 0 0 2 -1 1: C6116429:0016 C611642A:046B 01 000032E8:00000000 01:00000159 00000004 0 0 1502 15 c05c0040 368 4 1 1 2 sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode 0: 00000000:0016 00000000:0000 0A 00000000:00000000 00:00000000 00000000 0 0 773 1 c05c0360 300 0 0 2 -1 1: C6116429:0016 C611642A:046B 01 000032E8:00000000 01:000000F3 00000004 0 0 1502 15 c05c0040 368 4 1 1 2 sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode 0: 00000000:0016 00000000:0000 0A 00000000:00000000 00:00000000 00000000 0 0 773 1 c05c0360 300 0 0 2 -1 1: C6116429:0016 C611642A:046B 01 000032E8:00000000 01:0000008D 00000004 0 0 1502 15 c05c0040 368 4 1 1 2 sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode 0: 00000000:0016 00000000:0000 0A 00000000:00000000 00:00000000 00000000 0 0 773 1 c05c0360 300 0 0 2 -1 1: C6116429:0016 C611642A:046B 01 000032E8:00000000 01:00000027 00000004 0 0 1502 15 c05c0040 368 4 1 1 2 sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode 0: 00000000:0016 00000000:0000 0A 00000000:00000000 00:00000000 00000000 0 0 773 1 c05c0360 300 0 0 2 -1 1: C6116429:0016 C611642A:046B 01 000032E8:00000000 01:000002A1 00000005 0 0 1502 15 c05c0040 736 4 1 1 2 sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode 0: 00000000:0016 00000000:0000 0A 00000000:00000000 00:00000000 00000000 0 0 773 1 c05c0360 300 0 0 2 -1 1: C6116429:0016 C611642A:046B 01 000032E8:00000000 01:0000023B 00000005 0 0 1502 15 c05c0040 736 4 1 1 2 sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode 0: 00000000:0016 00000000:0000 0A 00000000:00000000 00:00000000 00000000 0 0 773 1 c05c0360 300 0 0 2 -1 1: C6116429:0016 C611642A:046B 01 000032E8:00000000 01:000001D5 00000005 0 0 1502 15 c05c0040 736 4 1 1 2 sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode 0: 00000000:0016 00000000:0000 0A 00000000:00000000 00:00000000 00000000 0 0 773 1 c05c0360 300 0 0 2 -1 1: C6116429:0016 C611642A:046B 01 000032E8:00000000 01:0000016F 00000005 0 0 1502 15 c05c0040 736 4 1 1 2 sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode 0: 00000000:0016 00000000:0000 0A 00000000:00000000 00:00000000 00000000 0 0 773 1 c05c0360 300 0 0 2 -1 1: C6116429:0016 C611642A:046B 01 000032E8:00000000 01:00000109 00000005 0 0 1502 15 c05c0040 736 4 1 1 2 sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode 0: 00000000:0016 00000000:0000 0A 00000000:00000000 00:00000000 00000000 0 0 773 1 c05c0360 300 0 0 2 -1 1: C6116429:0016 C611642A:046B 01 000032E8:00000000 01:000000A3 00000005 0 0 1502 15 c05c0040 736 4 1 1 2 sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode 0: 00000000:0016 00000000:0000 0A 00000000:00000000 00:00000000 00000000 0 0 773 1 c05c0360 300 0 0 2 -1 1: C6116429:0016 C611642A:046B 01 000032E8:00000000 01:0000003D 00000005 0 0 1502 15 c05c0040 736 4 1 1 2 sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode 0: 00000000:0016 00000000:0000 0A 00000000:00000000 00:00000000 00000000 0 0 7