Date: Fri, 30 Nov 2007 00:16:04 -0800 From: "Jack Vogel" <jfvogel@gmail.com> To: "Vitezslav Novy" <vnovy@vnovy.net> Cc: freebsd-stable@freebsd.org Subject: Re: 7.0 BETA3 - slow TCP upload (TSO related?) Message-ID: <2a41acea0711300016w1aa144fel1641b3dbf075e043@mail.gmail.com> In-Reply-To: <474FB9E5.9090208@vnovy.net> References: <474FB9E5.9090208@vnovy.net>
next in thread | previous in thread | raw e-mail | index | archive | help
On Nov 29, 2007 11:21 PM, Vitezslav Novy <vnovy@vnovy.net> wrote: > Hello, > > my configuration is > > kernel GENERIC > > em0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500 > options=18b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWCSUM,TSO4> > ether 00:19:d1:0f:1c:18 > inet 86.49.14.16 netmask 0xffffff00 broadcast 86.49.14.255 > media: Ethernet autoselect (100baseTX <full-duplex>) > status: active > > and standard "open" ipfw firewall and > natd -u -s -m -d -dynamic -n em0 > > I experience very slow TCP upload from this host - cca 50kbps. > I have some debug prints in kernel (mostly in ip_output and ipfw log) > and I see: > > 1/ outgoing packet appears in ip_output with ip_len 2924 and > m->pkthdr.csum_flags=1 > 2/ is diverted by firewall > 3/ Packet appears immediately again in ip_output with ip_len 2924 and > m->pkthdr.csum_flags=1 > 4/ Packet is accepted by firewall and dropped by ip_output with error 40 > EMSGSIZE > 5/ After cca 0.4s (tcp retransmit timeout?) new packet appears in > ip_output with ip_len 1488 and m->pkthdr.csum_flags=1 > 6/ is successfully diverted and accepted by ipfw and sent to wire. > 7/ after tcp ack is received new packet appears in ip_output with ip_len > 2924 and everything repeats > > > Packets are not changed by natd, beacause have src address of em0. > nat > > > Upload has normal speed (512kbps) if > I unset TSO on interface OR set net.inet.tcp.tso=0 OR (strange thing) > delete ipfw divert rule > > If necessary I will collect and send more info. TSO is silly at 100Mb, turn it off :) Jack
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?2a41acea0711300016w1aa144fel1641b3dbf075e043>