434 строки
17 KiB
Plaintext
434 строки
17 KiB
Plaintext
Linux Base Driver for 10 Gigabit Intel(R) Ethernet Network Connection
|
||
=====================================================================
|
||
|
||
March 14, 2011
|
||
|
||
|
||
Contents
|
||
========
|
||
|
||
- In This Release
|
||
- Identifying Your Adapter
|
||
- Building and Installation
|
||
- Command Line Parameters
|
||
- Improving Performance
|
||
- Additional Configurations
|
||
- Known Issues/Troubleshooting
|
||
- Support
|
||
|
||
|
||
|
||
In This Release
|
||
===============
|
||
|
||
This file describes the ixgb Linux Base Driver for the 10 Gigabit Intel(R)
|
||
Network Connection. This driver includes support for Itanium(R)2-based
|
||
systems.
|
||
|
||
For questions related to hardware requirements, refer to the documentation
|
||
supplied with your 10 Gigabit adapter. All hardware requirements listed apply
|
||
to use with Linux.
|
||
|
||
The following features are available in this kernel:
|
||
- Native VLANs
|
||
- Channel Bonding (teaming)
|
||
- SNMP
|
||
|
||
Channel Bonding documentation can be found in the Linux kernel source:
|
||
/Documentation/networking/bonding.txt
|
||
|
||
The driver information previously displayed in the /proc filesystem is not
|
||
supported in this release. Alternatively, you can use ethtool (version 1.6
|
||
or later), lspci, and iproute2 to obtain the same information.
|
||
|
||
Instructions on updating ethtool can be found in the section "Additional
|
||
Configurations" later in this document.
|
||
|
||
|
||
Identifying Your Adapter
|
||
========================
|
||
|
||
The following Intel network adapters are compatible with the drivers in this
|
||
release:
|
||
|
||
Controller Adapter Name Physical Layer
|
||
---------- ------------ --------------
|
||
82597EX Intel(R) PRO/10GbE LR/SR/CX4 10G Base-LR (1310 nm optical fiber)
|
||
Server Adapters 10G Base-SR (850 nm optical fiber)
|
||
10G Base-CX4(twin-axial copper cabling)
|
||
|
||
For more information on how to identify your adapter, go to the Adapter &
|
||
Driver ID Guide at:
|
||
|
||
http://support.intel.com/support/network/sb/CS-012904.htm
|
||
|
||
|
||
Building and Installation
|
||
=========================
|
||
|
||
select m for "Intel(R) PRO/10GbE support" located at:
|
||
Location:
|
||
-> Device Drivers
|
||
-> Network device support (NETDEVICES [=y])
|
||
-> Ethernet (10000 Mbit) (NETDEV_10000 [=y])
|
||
1. make modules && make modules_install
|
||
|
||
2. Load the module:
|
||
|
||
modprobe ixgb <parameter>=<value>
|
||
|
||
The insmod command can be used if the full
|
||
path to the driver module is specified. For example:
|
||
|
||
insmod /lib/modules/<KERNEL VERSION>/kernel/drivers/net/ixgb/ixgb.ko
|
||
|
||
With 2.6 based kernels also make sure that older ixgb drivers are
|
||
removed from the kernel, before loading the new module:
|
||
|
||
rmmod ixgb; modprobe ixgb
|
||
|
||
3. Assign an IP address to the interface by entering the following, where
|
||
x is the interface number:
|
||
|
||
ip addr add ethx <IP_address>
|
||
|
||
4. Verify that the interface works. Enter the following, where <IP_address>
|
||
is the IP address for another machine on the same subnet as the interface
|
||
that is being tested:
|
||
|
||
ping <IP_address>
|
||
|
||
|
||
Command Line Parameters
|
||
=======================
|
||
|
||
If the driver is built as a module, the following optional parameters are
|
||
used by entering them on the command line with the modprobe command using
|
||
this syntax:
|
||
|
||
modprobe ixgb [<option>=<VAL1>,<VAL2>,...]
|
||
|
||
For example, with two 10GbE PCI adapters, entering:
|
||
|
||
modprobe ixgb TxDescriptors=80,128
|
||
|
||
loads the ixgb driver with 80 TX resources for the first adapter and 128 TX
|
||
resources for the second adapter.
|
||
|
||
The default value for each parameter is generally the recommended setting,
|
||
unless otherwise noted.
|
||
|
||
FlowControl
|
||
Valid Range: 0-3 (0=none, 1=Rx only, 2=Tx only, 3=Rx&Tx)
|
||
Default: Read from the EEPROM
|
||
If EEPROM is not detected, default is 1
|
||
This parameter controls the automatic generation(Tx) and response(Rx) to
|
||
Ethernet PAUSE frames. There are hardware bugs associated with enabling
|
||
Tx flow control so beware.
|
||
|
||
RxDescriptors
|
||
Valid Range: 64-512
|
||
Default Value: 512
|
||
This value is the number of receive descriptors allocated by the driver.
|
||
Increasing this value allows the driver to buffer more incoming packets.
|
||
Each descriptor is 16 bytes. A receive buffer is also allocated for
|
||
each descriptor and can be either 2048, 4056, 8192, or 16384 bytes,
|
||
depending on the MTU setting. When the MTU size is 1500 or less, the
|
||
receive buffer size is 2048 bytes. When the MTU is greater than 1500 the
|
||
receive buffer size will be either 4056, 8192, or 16384 bytes. The
|
||
maximum MTU size is 16114.
|
||
|
||
RxIntDelay
|
||
Valid Range: 0-65535 (0=off)
|
||
Default Value: 72
|
||
This value delays the generation of receive interrupts in units of
|
||
0.8192 microseconds. Receive interrupt reduction can improve CPU
|
||
efficiency if properly tuned for specific network traffic. Increasing
|
||
this value adds extra latency to frame reception and can end up
|
||
decreasing the throughput of TCP traffic. If the system is reporting
|
||
dropped receives, this value may be set too high, causing the driver to
|
||
run out of available receive descriptors.
|
||
|
||
TxDescriptors
|
||
Valid Range: 64-4096
|
||
Default Value: 256
|
||
This value is the number of transmit descriptors allocated by the driver.
|
||
Increasing this value allows the driver to queue more transmits. Each
|
||
descriptor is 16 bytes.
|
||
|
||
XsumRX
|
||
Valid Range: 0-1
|
||
Default Value: 1
|
||
A value of '1' indicates that the driver should enable IP checksum
|
||
offload for received packets (both UDP and TCP) to the adapter hardware.
|
||
|
||
|
||
Improving Performance
|
||
=====================
|
||
|
||
With the 10 Gigabit server adapters, the default Linux configuration will
|
||
very likely limit the total available throughput artificially. There is a set
|
||
of configuration changes that, when applied together, will increase the ability
|
||
of Linux to transmit and receive data. The following enhancements were
|
||
originally acquired from settings published at http://www.spec.org/web99/ for
|
||
various submitted results using Linux.
|
||
|
||
NOTE: These changes are only suggestions, and serve as a starting point for
|
||
tuning your network performance.
|
||
|
||
The changes are made in three major ways, listed in order of greatest effect:
|
||
- Use ip link to modify the mtu (maximum transmission unit) and the txqueuelen
|
||
parameter.
|
||
- Use sysctl to modify /proc parameters (essentially kernel tuning)
|
||
- Use setpci to modify the MMRBC field in PCI-X configuration space to increase
|
||
transmit burst lengths on the bus.
|
||
|
||
NOTE: setpci modifies the adapter's configuration registers to allow it to read
|
||
up to 4k bytes at a time (for transmits). However, for some systems the
|
||
behavior after modifying this register may be undefined (possibly errors of
|
||
some kind). A power-cycle, hard reset or explicitly setting the e6 register
|
||
back to 22 (setpci -d 8086:1a48 e6.b=22) may be required to get back to a
|
||
stable configuration.
|
||
|
||
- COPY these lines and paste them into ixgb_perf.sh:
|
||
#!/bin/bash
|
||
echo "configuring network performance , edit this file to change the interface
|
||
or device ID of 10GbE card"
|
||
# set mmrbc to 4k reads, modify only Intel 10GbE device IDs
|
||
# replace 1a48 with appropriate 10GbE device's ID installed on the system,
|
||
# if needed.
|
||
setpci -d 8086:1a48 e6.b=2e
|
||
# set the MTU (max transmission unit) - it requires your switch and clients
|
||
# to change as well.
|
||
# set the txqueuelen
|
||
# your ixgb adapter should be loaded as eth1 for this to work, change if needed
|
||
ip li set dev eth1 mtu 9000 txqueuelen 1000 up
|
||
# call the sysctl utility to modify /proc/sys entries
|
||
sysctl -p ./sysctl_ixgb.conf
|
||
- END ixgb_perf.sh
|
||
|
||
- COPY these lines and paste them into sysctl_ixgb.conf:
|
||
# some of the defaults may be different for your kernel
|
||
# call this file with sysctl -p <this file>
|
||
# these are just suggested values that worked well to increase throughput in
|
||
# several network benchmark tests, your mileage may vary
|
||
|
||
### IPV4 specific settings
|
||
# turn TCP timestamp support off, default 1, reduces CPU use
|
||
net.ipv4.tcp_timestamps = 0
|
||
# turn SACK support off, default on
|
||
# on systems with a VERY fast bus -> memory interface this is the big gainer
|
||
net.ipv4.tcp_sack = 0
|
||
# set min/default/max TCP read buffer, default 4096 87380 174760
|
||
net.ipv4.tcp_rmem = 10000000 10000000 10000000
|
||
# set min/pressure/max TCP write buffer, default 4096 16384 131072
|
||
net.ipv4.tcp_wmem = 10000000 10000000 10000000
|
||
# set min/pressure/max TCP buffer space, default 31744 32256 32768
|
||
net.ipv4.tcp_mem = 10000000 10000000 10000000
|
||
|
||
### CORE settings (mostly for socket and UDP effect)
|
||
# set maximum receive socket buffer size, default 131071
|
||
net.core.rmem_max = 524287
|
||
# set maximum send socket buffer size, default 131071
|
||
net.core.wmem_max = 524287
|
||
# set default receive socket buffer size, default 65535
|
||
net.core.rmem_default = 524287
|
||
# set default send socket buffer size, default 65535
|
||
net.core.wmem_default = 524287
|
||
# set maximum amount of option memory buffers, default 10240
|
||
net.core.optmem_max = 524287
|
||
# set number of unprocessed input packets before kernel starts dropping them; default 300
|
||
net.core.netdev_max_backlog = 300000
|
||
- END sysctl_ixgb.conf
|
||
|
||
Edit the ixgb_perf.sh script if necessary to change eth1 to whatever interface
|
||
your ixgb driver is using and/or replace '1a48' with appropriate 10GbE device's
|
||
ID installed on the system.
|
||
|
||
NOTE: Unless these scripts are added to the boot process, these changes will
|
||
only last only until the next system reboot.
|
||
|
||
|
||
Resolving Slow UDP Traffic
|
||
--------------------------
|
||
If your server does not seem to be able to receive UDP traffic as fast as it
|
||
can receive TCP traffic, it could be because Linux, by default, does not set
|
||
the network stack buffers as large as they need to be to support high UDP
|
||
transfer rates. One way to alleviate this problem is to allow more memory to
|
||
be used by the IP stack to store incoming data.
|
||
|
||
For instance, use the commands:
|
||
sysctl -w net.core.rmem_max=262143
|
||
and
|
||
sysctl -w net.core.rmem_default=262143
|
||
to increase the read buffer memory max and default to 262143 (256k - 1) from
|
||
defaults of max=131071 (128k - 1) and default=65535 (64k - 1). These variables
|
||
will increase the amount of memory used by the network stack for receives, and
|
||
can be increased significantly more if necessary for your application.
|
||
|
||
|
||
Additional Configurations
|
||
=========================
|
||
|
||
Configuring the Driver on Different Distributions
|
||
-------------------------------------------------
|
||
Configuring a network driver to load properly when the system is started is
|
||
distribution dependent. Typically, the configuration process involves adding
|
||
an alias line to /etc/modprobe.conf as well as editing other system startup
|
||
scripts and/or configuration files. Many popular Linux distributions ship
|
||
with tools to make these changes for you. To learn the proper way to
|
||
configure a network device for your system, refer to your distribution
|
||
documentation. If during this process you are asked for the driver or module
|
||
name, the name for the Linux Base Driver for the Intel 10GbE Family of
|
||
Adapters is ixgb.
|
||
|
||
Viewing Link Messages
|
||
---------------------
|
||
Link messages will not be displayed to the console if the distribution is
|
||
restricting system messages. In order to see network driver link messages on
|
||
your console, set dmesg to eight by entering the following:
|
||
|
||
dmesg -n 8
|
||
|
||
NOTE: This setting is not saved across reboots.
|
||
|
||
|
||
Jumbo Frames
|
||
------------
|
||
The driver supports Jumbo Frames for all adapters. Jumbo Frames support is
|
||
enabled by changing the MTU to a value larger than the default of 1500.
|
||
The maximum value for the MTU is 16114. Use the ip command to
|
||
increase the MTU size. For example:
|
||
|
||
ip li set dev ethx mtu 9000
|
||
|
||
The maximum MTU setting for Jumbo Frames is 16114. This value coincides
|
||
with the maximum Jumbo Frames size of 16128.
|
||
|
||
|
||
ethtool
|
||
-------
|
||
The driver utilizes the ethtool interface for driver configuration and
|
||
diagnostics, as well as displaying statistical information. The ethtool
|
||
version 1.6 or later is required for this functionality.
|
||
|
||
The latest release of ethtool can be found from
|
||
https://www.kernel.org/pub/software/network/ethtool/
|
||
|
||
NOTE: The ethtool version 1.6 only supports a limited set of ethtool options.
|
||
Support for a more complete ethtool feature set can be enabled by
|
||
upgrading to the latest version.
|
||
|
||
|
||
NAPI
|
||
----
|
||
|
||
NAPI (Rx polling mode) is supported in the ixgb driver. NAPI is enabled
|
||
or disabled based on the configuration of the kernel. see CONFIG_IXGB_NAPI
|
||
|
||
See www.cyberus.ca/~hadi/usenix-paper.tgz for more information on NAPI.
|
||
|
||
|
||
Known Issues/Troubleshooting
|
||
============================
|
||
|
||
NOTE: After installing the driver, if your Intel Network Connection is not
|
||
working, verify in the "In This Release" section of the readme that you have
|
||
installed the correct driver.
|
||
|
||
Intel(R) PRO/10GbE CX4 Server Adapter Cable Interoperability Issue with
|
||
Fujitsu XENPAK Module in SmartBits Chassis
|
||
---------------------------------------------------------------------
|
||
Excessive CRC errors may be observed if the Intel(R) PRO/10GbE CX4
|
||
Server adapter is connected to a Fujitsu XENPAK CX4 module in a SmartBits
|
||
chassis using 15 m/24AWG cable assemblies manufactured by Fujitsu or Leoni.
|
||
The CRC errors may be received either by the Intel(R) PRO/10GbE CX4
|
||
Server adapter or the SmartBits. If this situation occurs using a different
|
||
cable assembly may resolve the issue.
|
||
|
||
CX4 Server Adapter Cable Interoperability Issues with HP Procurve 3400cl
|
||
Switch Port
|
||
------------------------------------------------------------------------
|
||
Excessive CRC errors may be observed if the Intel(R) PRO/10GbE CX4 Server
|
||
adapter is connected to an HP Procurve 3400cl switch port using short cables
|
||
(1 m or shorter). If this situation occurs, using a longer cable may resolve
|
||
the issue.
|
||
|
||
Excessive CRC errors may be observed using Fujitsu 24AWG cable assemblies that
|
||
Are 10 m or longer or where using a Leoni 15 m/24AWG cable assembly. The CRC
|
||
errors may be received either by the CX4 Server adapter or at the switch. If
|
||
this situation occurs, using a different cable assembly may resolve the issue.
|
||
|
||
|
||
Jumbo Frames System Requirement
|
||
-------------------------------
|
||
Memory allocation failures have been observed on Linux systems with 64 MB
|
||
of RAM or less that are running Jumbo Frames. If you are using Jumbo
|
||
Frames, your system may require more than the advertised minimum
|
||
requirement of 64 MB of system memory.
|
||
|
||
|
||
Performance Degradation with Jumbo Frames
|
||
-----------------------------------------
|
||
Degradation in throughput performance may be observed in some Jumbo frames
|
||
environments. If this is observed, increasing the application's socket buffer
|
||
size and/or increasing the /proc/sys/net/ipv4/tcp_*mem entry values may help.
|
||
See the specific application manual and /usr/src/linux*/Documentation/
|
||
networking/ip-sysctl.txt for more details.
|
||
|
||
|
||
Allocating Rx Buffers when Using Jumbo Frames
|
||
---------------------------------------------
|
||
Allocating Rx buffers when using Jumbo Frames on 2.6.x kernels may fail if
|
||
the available memory is heavily fragmented. This issue may be seen with PCI-X
|
||
adapters or with packet split disabled. This can be reduced or eliminated
|
||
by changing the amount of available memory for receive buffer allocation, by
|
||
increasing /proc/sys/vm/min_free_kbytes.
|
||
|
||
|
||
Multiple Interfaces on Same Ethernet Broadcast Network
|
||
------------------------------------------------------
|
||
Due to the default ARP behavior on Linux, it is not possible to have
|
||
one system on two IP networks in the same Ethernet broadcast domain
|
||
(non-partitioned switch) behave as expected. All Ethernet interfaces
|
||
will respond to IP traffic for any IP address assigned to the system.
|
||
This results in unbalanced receive traffic.
|
||
|
||
If you have multiple interfaces in a server, do either of the following:
|
||
|
||
- Turn on ARP filtering by entering:
|
||
echo 1 > /proc/sys/net/ipv4/conf/all/arp_filter
|
||
|
||
- Install the interfaces in separate broadcast domains - either in
|
||
different switches or in a switch partitioned to VLANs.
|
||
|
||
|
||
UDP Stress Test Dropped Packet Issue
|
||
--------------------------------------
|
||
Under small packets UDP stress test with 10GbE driver, the Linux system
|
||
may drop UDP packets due to the fullness of socket buffers. You may want
|
||
to change the driver's Flow Control variables to the minimum value for
|
||
controlling packet reception.
|
||
|
||
|
||
Tx Hangs Possible Under Stress
|
||
------------------------------
|
||
Under stress conditions, if TX hangs occur, turning off TSO
|
||
"ethtool -K eth0 tso off" may resolve the problem.
|
||
|
||
|
||
Support
|
||
=======
|
||
|
||
For general information, go to the Intel support website at:
|
||
|
||
http://support.intel.com
|
||
|
||
or the Intel Wired Networking project hosted by Sourceforge at:
|
||
|
||
http://sourceforge.net/projects/e1000
|
||
|
||
If an issue is identified with the released source code on the supported
|
||
kernel with a supported adapter, email the specific information related
|
||
to the issue to e1000-devel@lists.sf.net
|