[Bug 894608] Re: Implementing a bridge slows 10G network

Mike Imelfort 894608 at bugs.launchpad.net
Sun Nov 27 11:00:27 UTC 2011


Thanks for getting back to me.

Here is brctl show output:

$ brctl show
bridge name	bridge id		STP enabled	interfaces
br0		8000.0010187ee074	no		eth4

and ip link:

$ ip link
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000
    link/ether f0:4d:a2:3b:9a:9e brd ff:ff:ff:ff:ff:ff
3: eth1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000
    link/ether f0:4d:a2:3b:9a:a0 brd ff:ff:ff:ff:ff:ff
4: eth2: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000
    link/ether f0:4d:a2:3b:9a:a2 brd ff:ff:ff:ff:ff:ff
5: eth3: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000
    link/ether f0:4d:a2:3b:9a:a4 brd ff:ff:ff:ff:ff:ff
6: eth4: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000
    link/ether 00:10:18:7e:e0:74 brd ff:ff:ff:ff:ff:ff
7: eth5: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000
    link/ether 00:10:18:7e:e0:76 brd ff:ff:ff:ff:ff:ff
8: br0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN 
    link/ether 00:10:18:7e:e0:74 brd ff:ff:ff:ff:ff:ff

Also:

"Several sources suggest that turning odd tso, and perhaps also sg and
tx, might help. Could you try"

Tried this but it made no noticeable difference.

Thanks for your help so far.

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https://bugs.launchpad.net/bugs/894608

Title:
  Implementing a bridge slows 10G network

Status in “bridge-utils” package in Ubuntu:
  Incomplete
Status in “linux” package in Ubuntu:
  Incomplete

Bug description:
  Installing bridge-utils and then setting up a bridge in
  /etc/netwrok/interfaces decimates my netwrok speed. Uninstalling the
  package and doing a reboot restores the speed.

  This bug was originally posted here:
  https://bugs.launchpad.net/qemu/+bug/861141 but I now realise it is
  bridge-utils specific.

  Hardware:
  I have two identical machines (DELL poweredge R815), each with Broadcom NetXtreme II BCM57711 10-Gigabit PCIe connected via a 10G switch.
  Each machine runs 4 socket 12 core AMD Opteron(tm) Processor 6174 and 128GB of ram

  Software:
  Both machines ar running ubuntu server 10.04 lts Kernels are:
  Linux whitlam 2.6.32-28-server #55-Ubuntu SMP Mon Jan 10 23:57:16 UTC 2011 x86_64 GNU/Linux
  Linux fraser 2.6.32-28-server #55-Ubuntu SMP Mon Jan 10 23:57:16 UTC 2011 x86_64 GNU/Linux

  I have installed iperf on both machines.

  The tests here involve running whitlam as the iperf server and fraser as the client.
  On whitlam I run:
  bioadmin at whitlam:~# iperf -sm

  On fraser I run:
  bioadmin at fraser:~# iperf -c whitlam -d

  before installation I get:
  bioadmin at whitlam:~# iperf -sm
  ------------------------------------------------------------
  Server listening on TCP port 5001
  TCP window size: 85.3 KByte (default)
  ------------------------------------------------------------
  [ 5] local 10.168.48.14 port 5001 connected with 10.168.48.13 port 37960
  ------------------------------------------------------------
  Client connecting to 10.168.48.13, TCP port 5001
  TCP window size: 110 KByte (default)
  ------------------------------------------------------------
  [ 6] local 10.168.48.14 port 49627 connected with 10.168.48.13 port 5001
  Waiting for server threads to complete. Interrupt again to force quit.
  [ 5] 0.0-10.0 sec 10.8 GBytes 9.23 Gbits/sec
  [ 5] MSS size 1448 bytes (MTU 1500 bytes, ethernet)
  [ 6] 0.0-10.0 sec 10.6 GBytes 9.11 Gbits/sec
  [ 6] MSS size 1448 bytes (MTU 1500 bytes, ethernet)

  Which is nice.

  Next I run:

  sudo aptitude -y install bridge-utils

  and then I add a bridge to the interfaces file like thus:

  FROM:
  # This file describes the network interfaces available on your system
  # and how to activate them. For more information, see interfaces(5).

  # The loopback network interface
  auto lo
  iface lo inet loopback

  # The primary network interface
  auto eth4
  iface eth4 inet static
   address xx.xx.xx.xx
   netmask 255.255.255.0
   network xx.xx.xx.0
   broadcast xx.xx.xx.255
   gateway xx.xx.xx.1
   # dns-* options are implemented by the resolvconf package, if installed
   dns-nameservers blah blah

  TO:

  # This file describes the network interfaces available on your system
  # and how to activate them. For more information, see interfaces(5).

  # The loopback network interface
  auto lo
  iface lo inet loopback

  # The primary network interface
  #auto eth4
  #iface eth4 inet manual

  auto br0
  iface br0 inet static
   address xx.xx.xx.xx
   netmask 255.255.255.0
   network xx.xx.xx.0
   broadcast xx.xx.xx.255
   gateway xx.xx.xx.1
   bridge_ports eth4
   bridge_stp off
   # dns-* options are implemented by the resolvconf package, if installed
   dns-nameservers blah blah

  And restart networking

  sudo /etc/init.d/netwroking restart

  Which results in:
  bioadmin at whitlam:~# iperf -sm
  ------------------------------------------------------------
  Server listening on TCP port 5001
  TCP window size: 85.3 KByte (default)
  ------------------------------------------------------------
  [ 4] local 10.168.48.14 port 5001 connected with 10.168.48.13 port 56405
  ------------------------------------------------------------
  Client connecting to 10.168.48.13, TCP port 5001
  TCP window size: 1.25 MByte (default)
  ------------------------------------------------------------
  [ 6] local 10.168.48.14 port 57001 connected with 10.168.48.13 port 5001
  Waiting for server threads to complete. Interrupt again to force quit.
  [ ID] Interval Transfer Bandwidth
  [ 4] 0.0-10.0 sec 10.5 GBytes 9.00 Gbits/sec
  [ 4] MSS size 1448 bytes (MTU 1500 bytes, ethernet)
  [ 6] 0.0-10.0 sec 2.51 GBytes 2.15 Gbits/sec
  [ 6] MSS size 1448 bytes (MTU 1500 bytes, ethernet)

  Note that the connection from the machine with bridge-utils installed
  (fraser) to the other machine (whitlam) is not affected. Only the
  connection from whitlam to fraser.

  Both machines are fresh installs with nfs-common, iperf installed.
  Fraser also has bridge-utils

  Any help is very much appreciated!

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