From owner-freebsd-bugs@FreeBSD.ORG Wed Mar 9 12:30:12 2011 Return-Path: Delivered-To: freebsd-bugs@hub.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 629AF106567B for ; Wed, 9 Mar 2011 12:30:12 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (freefall.freebsd.org [IPv6:2001:4f8:fff6::28]) by mx1.freebsd.org (Postfix) with ESMTP id 1A7318FC29 for ; Wed, 9 Mar 2011 12:30:12 +0000 (UTC) Received: from freefall.freebsd.org (localhost [127.0.0.1]) by freefall.freebsd.org (8.14.4/8.14.4) with ESMTP id p29CUBxM094660 for ; Wed, 9 Mar 2011 12:30:11 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.14.4/8.14.4/Submit) id p29CUBJE094657; Wed, 9 Mar 2011 12:30:11 GMT (envelope-from gnats) Resent-Date: Wed, 9 Mar 2011 12:30:11 GMT Resent-Message-Id: <201103091230.p29CUBJE094657@freefall.freebsd.org> Resent-From: FreeBSD-gnats-submit@FreeBSD.org (GNATS Filer) Resent-To: freebsd-bugs@FreeBSD.org Resent-Reply-To: FreeBSD-gnats-submit@FreeBSD.org, Slawa Olhovchenkov Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E4A231065672 for ; Wed, 9 Mar 2011 12:29:13 +0000 (UTC) (envelope-from nobody@FreeBSD.org) Received: from red.freebsd.org (red.freebsd.org [IPv6:2001:4f8:fff6::22]) by mx1.freebsd.org (Postfix) with ESMTP id D3FAC8FC14 for ; Wed, 9 Mar 2011 12:29:13 +0000 (UTC) Received: from red.freebsd.org (localhost [127.0.0.1]) by red.freebsd.org (8.14.4/8.14.4) with ESMTP id p29CTDcv033516 for ; Wed, 9 Mar 2011 12:29:13 GMT (envelope-from nobody@red.freebsd.org) Received: (from nobody@localhost) by red.freebsd.org (8.14.4/8.14.4/Submit) id p29CTDcb033511; Wed, 9 Mar 2011 12:29:13 GMT (envelope-from nobody) Message-Id: <201103091229.p29CTDcb033511@red.freebsd.org> Date: Wed, 9 Mar 2011 12:29:13 GMT From: Slawa Olhovchenkov To: freebsd-gnats-submit@FreeBSD.org X-Send-Pr-Version: www-3.1 Cc: Subject: kern/155407: Exhausted net.inet.tcp.reass.maxsegments block recovering tcp session X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 09 Mar 2011 12:30:12 -0000 >Number: 155407 >Category: kern >Synopsis: Exhausted net.inet.tcp.reass.maxsegments block recovering tcp session >Confidential: no >Severity: critical >Priority: high >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Wed Mar 09 12:30:11 UTC 2011 >Closed-Date: >Last-Modified: >Originator: Slawa Olhovchenkov >Release: 8.2 >Organization: >Environment: FreeBSD mail.haustus.ru 8.2-RC3 FreeBSD 8.2-RC3 #0: Sun Jan 30 06:28:31 UTC 2011 root@mason.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC amd64 >Description: Exhausted net.inet.tcp.reass.maxsegments block recovering tcp session (for this socket and any other socket waiting for retransmited packets). After exhausted net.inet.tcp.reass.maxsegments allocation new entry in tcp_reass failed (for this socket and any other socket waiting for retransmited packets). te = uma_zalloc(V_tcp_reass_zone, M_NOWAIT); if (te == NULL) { TCPSTAT_INC(tcps_rcvmemdrop); m_freem(m); *tlenp = 0; return (0); } That is packet can be reduce reassemble queue dropped. >How-To-Repeat: Need high bandwidth-delay channel with high, but rare drop. After lost incoming TCP segment and before got retranmited this segment net.inet.tcp.reass.maxsegments exhausted. Software emulation: Tuning by http://fasterdata.es.net/fasterdata/host-tuning/freebsd/ sysctl net.inet.tcp.recvspace=1048576 sysctl net.inet.ip.dummynet.pipe_slot_limit=3000 ipfw pipe 1 config delay 300 queue 3000 ipfw add 100 pipe 1 ip from test_hot to me fetch http://test_host/big_file After reach 7MB/s: ipfw pipe 1 config delay 300 queue 3000 plr 0.1 >Fix: Workaround: set net.inet.tcp.reass.maxsegments in /boot/loader.conf to big value. >Release-Note: >Audit-Trail: >Unformatted: