Documentation: ixgb: Prepare documentation for RST conversion

.. SPDX-License-Identifier: GPL-2.0+

Linux Base Driver for 10 Gigabit Intel(R) Ethernet Network Connection

=====================================================================

March 14, 2011

October 1, 2018

Contents

- In This Release

- Identifying Your Adapter

- Building and Installation

- Command Line Parameters

- Improving Performance

- Additional Configurations

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)

+------------+------------------------------+----------------------------------+

| Controller | Adapter Name                 | Physical Layer                   |

+============+==============================+==================================+

| 82597EX    | Intel(R) PRO/10GbE LR/SR/CX4 | - 10G Base-LR (fiber)            |

|            | Server Adapters              | - 10G Base-SR (fiber)            |

|            |                              | - 10G Base-CX4 (copper)          |

+------------+------------------------------+----------------------------------+

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>

    https://support.intel.com

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:

this syntax::

    modprobe ixgb [<option>=<VAL1>,<VAL2>,...]

For example, with two 10GbE PCI adapters, entering:

For example, with two 10GbE PCI adapters, entering::

    modprobe ixgb TxDescriptors=80,128

The default value for each parameter is generally the recommended setting,

unless otherwise noted.

Copybreak

---------

:Valid Range: 0-XXXX

:Default Value: 256

    This is the maximum size of packet that is copied to a new buffer on

    receive.

Debug

-----

:Valid Range: 0-16 (0=none,...,16=all)

:Default Value: 0

    This parameter adjusts the level of debug messages displayed in the

    system logs.

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

-----------

:Valid Range: 0-3 (0=none, 1=Rx only, 2=Tx only, 3=Rx&Tx)

:Default Value: 1 if no EEPROM, otherwise read from EEPROM

    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

-------------

:Valid Range: 64-4096

:Default Value: 1024

    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

    receive buffer size will be either 4056, 8192, or 16384 bytes.  The

    maximum MTU size is 16114.

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.

RxIntDelay

Valid Range: 0-65535 (0=off)

Default Value: 72

----------

: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

    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.

TxIntDelay

----------

:Valid Range: 0-65535 (0=off)

:Default Value: 32

    This value delays the generation of transmit interrupts in units of

    0.8192 microseconds.  Transmit interrupt reduction can improve CPU

    efficiency if properly tuned for specific network traffic.  Increasing

    this value adds extra latency to frame transmission and can end up

    decreasing the throughput of TCP traffic.  If this value is set too high,

    it will cause the driver to run out of available transmit descriptors.

XsumRX

Valid Range: 0-1

Default Value: 1

------

: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.

RxFCHighThresh

--------------

:Valid Range: 1,536-262,136 (0x600 - 0x3FFF8, 8 byte granularity)

:Default Value: 196,608 (0x30000)

    Receive Flow control high threshold (when we send a pause frame)

RxFCLowThresh

-------------

:Valid Range: 64-262,136 (0x40 - 0x3FFF8, 8 byte granularity)

:Default Value: 163,840 (0x28000)

    Receive Flow control low threshold (when we send a resume frame)

FCReqTimeout

------------

:Valid Range: 1-65535

:Default Value: 65535

    Flow control request timeout (how long to pause the link partner's tx)

IntDelayEnable

--------------

:Value Range: 0,1

:Default Value: 1

    Interrupt Delay, 0 disables transmit interrupt delay and 1 enables it.

Improving Performance

=====================

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

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

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

  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"

  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

  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

NOTE:

  Unless these scripts are added to the boot process, these changes will

  only last only until the next system reboot.

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:

For instance, use the commands::

    sysctl -w net.core.rmem_max=262143

and

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

---------------------

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:

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:

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

Ethtool

-------

The driver utilizes the ethtool interface for driver configuration and

diagnostics, as well as displaying statistical information.  The ethtool

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.

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.

  See www.cyberus.ca/~hadi/usenix-paper.tgz for more information on NAPI.

See https://wiki.linuxfoundation.org/networking/napi for more information on

NAPI.

Known Issues/Troubleshooting

============================

  NOTE: After installing the driver, if your Intel Network Connection is not

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

  ---------------------------------------------------------------------

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.

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

  ------------------------------------------------------------------------

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

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

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

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

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

If you have multiple interfaces in a server, do either of the following:

  - Turn on ARP filtering by entering:

  - 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

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

Support

=======

For general information, go to the Intel support website at:

    http://support.intel.com

https://www.intel.com/support/

or the Intel Wired Networking project hosted by Sourceforge at:

    http://sourceforge.net/projects/e1000

https://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

If an issue is identified with the released source code on a supported kernel

with a supported adapter, email the specific information related to the issue

to e1000-devel@lists.sf.net