From owner-freebsd-net Sun Mar 23 9: 7:28 2003 Delivered-To: freebsd-net@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 82B5437B405 for ; Sun, 23 Mar 2003 09:07:25 -0800 (PST) Received: from samson.dc.luth.se (samson.dc.luth.se [130.240.112.30]) by mx1.FreeBSD.org (Postfix) with ESMTP id 5260943F75 for ; Sun, 23 Mar 2003 09:07:23 -0800 (PST) (envelope-from bj@dc.luth.se) Received: from dc.luth.se (root@bompe.dc.luth.se [130.240.60.42]) by samson.dc.luth.se (8.12.5/8.12.5) with ESMTP id h2NH7LjY026649 for ; Sun, 23 Mar 2003 18:07:21 +0100 (MET) Received: from bompe.dc.luth.se (bj@localhost.dc.luth.se [127.0.0.1]) by dc.luth.se (8.12.6/8.11.3) with ESMTP id h2NH7LKl021437 for ; Sun, 23 Mar 2003 18:07:21 +0100 (CET) (envelope-from bj@bompe.dc.luth.se) Message-Id: <200303231707.h2NH7LKl021437@dc.luth.se> X-Mailer: exmh version 2.5 07/13/2001 with nmh-1.0.4 To: freebsd-net@freebsd.org Reply-To: bj@dc.luth.se X-Disposition-notification-to: Borje.Josefsson@dc.luth.se X-Return-receipt-to: Borje.Josefsson@dc.luth.se Dcc: Subject: Does net.inet.tcp.inflight_enable work as expected? From: Borje Josefsson Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Date: Sun, 23 Mar 2003 18:07:21 +0100 Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org Hello, I have been playing around with the TCP parameters to try to tune my = system for high BW long distance transfer. Sending host with -CURRENT (as of yesterday) GigE card (bge) and the = following parameters set: kern.ipc.maxsockbuf: 8388608 net.inet.tcp.sendspace: 3230781 net.inet.tcp.recvspace: 3230781 net.inet.tcp.rfc1323: 1 net.inet.tcp.inflight_enable: 0 net.inet.tcp.inflight_min: 16000 net.inet.tcp.slowstart_flightsize: 8 kern.ipc.nmbclusters: 9024 This gives (with ttcp) between a pair of hosts 80 km (50 miles) apart - = with a RTT of 1.6 ms: root@stinky 33# ttcp -s -t -f m -l 61440 -n 20345 dino = ttcp-t: buflen=3D61440, nbuf=3D20345, align=3D16384/0, port=3D5001 tcp = -> dino ttcp-t: socket ttcp-t: connect ttcp-t: 1249996800 bytes in 27.26 real seconds =3D 349.86 Mbit/sec +++ ttcp-t: 20345 I/O calls, msec/call =3D 1.37, calls/sec =3D 746.37 ttcp-t: 0.0user 15.9sys 0:27real 58% 15i+354d 416maxrss 0+0pf 0+45863csw During that time "netstat 1" shows: input (Total) output packets errs bytes packets errs bytes colls 14888 0 982608 26946 0 40793188 0 14956 0 987096 27116 0 41049856 0 14857 0 980562 26902 0 40728292 0 15025 0 991650 27201 0 41178314 0 14808 0 977328 26818 0 40601116 0 15100 0 996600 27327 0 41370238 0 14801 0 976866 26818 0 40600244 0 14877 0 981882 26903 0 40728982 0 14934 0 985644 26945 0 40792362 0 14985 0 989010 26947 0 40792598 0 14924 0 984984 26904 0 40729392 0 15033 0 992178 27032 0 40921424 0 --------------------> Then I do this: root@stinky 34# sysctl net.inet.tcp.inflight_enable=3D1 net.inet.tcp.inflight_enable: 0 -> 1 And get: root@stinky 35# ttcp -s -t -f m -l 61440 -n 20345 dino ttcp-t: buflen=3D61440, nbuf=3D20345, align=3D16384/0, port=3D5001 tcp = -> dino ttcp-t: socket ttcp-t: connect ttcp-t: 1249996800 bytes in 458.75 real seconds =3D 20.79 Mbit/sec +++ ttcp-t: 20345 I/O calls, msec/call =3D 23.09, calls/sec =3D 44.35 ttcp-t: 0.1user 408.5sys 7:38real 89% 15i+353d 416maxrss 0+0pf = 62662+100667csw During that time "netstat 1" shows: input (Total) output packets errs bytes packets errs bytes colls 1095 0 72270 2106 0 3185530 0 1093 0 72138 2123 0 3212886 0 978 0 64548 1919 0 2902774 0 946 0 62436 1857 0 2810162 0 1040 0 68640 2044 0 3092024 0 879 0 58014 1740 0 2633024 0 1008 0 66528 1994 0 3016324 0 937 0 61842 1867 0 2825302 0 1034 0 68244 2043 0 3090510 0 963 0 63558 1911 0 2891918 0 941 0 62106 1865 0 2821754 0 991 0 65406 1911 0 2891918 0 1007 0 66462 1910 0 2889132 0 1048 0 69168 1994 0 3017580 0 1062 0 70092 2041 0 3087466 0 998 0 65868 1912 0 2893432 0 1091 0 72006 2120 0 3207072 0 962 0 63492 1871 0 2831358 0 Either I have completely misunderstood the effect of inflight_enable, or = something is very wrong?!? Any ideas? --B=F6rje To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message