From 2115a6432911b669bec037686066c7bbc70cc68e Mon Sep 17 00:00:00 2001
From: Jesse Brandeburg <jesse.brandeburg@intel.com>
Date: Tue, 8 Jul 2008 15:51:57 -0700
Subject: [PATCH] ixgb: update readme text

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
---
 Documentation/networking/ixgb.txt | 419 +++++++++++++++++++++++-------
 1 file changed, 320 insertions(+), 99 deletions(-)

diff --git a/Documentation/networking/ixgb.txt b/Documentation/networking/ixgb.txt
index 7c98277777e..a0d0ffb5e58 100644
--- a/Documentation/networking/ixgb.txt
+++ b/Documentation/networking/ixgb.txt
@@ -1,7 +1,7 @@
-Linux* Base Driver for the Intel(R) PRO/10GbE Family of Adapters
-================================================================
+Linux Base Driver for 10 Gigabit Intel(R) Network Connection
+=============================================================
 
-November 17, 2004
+October 9, 2007
 
 
 Contents
@@ -9,94 +9,151 @@ 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 Linux* Base Driver for the Intel(R) PRO/10GbE Family 
-of Adapters, version 1.0.x.  
+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 ifconfig to obtain the same information.
+
+Instructions on updating ethtool can be found in the section "Additional
+Configurations" later in this document.
 
-For questions related to hardware requirements, refer to the documentation 
-supplied with your Intel PRO/10GbE adapter. All hardware requirements listed 
-apply to use with Linux.
 
 Identifying Your Adapter
 ========================
 
-To verify your Intel adapter is supported, find the board ID number on the 
-adapter. Look for a label that has a barcode and a number in the format  
-A12345-001. 
+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:
 
-Use the above information and the Adapter & Driver ID Guide at:
+     rmmod ixgb; modprobe ixgb
 
-  http://support.intel.com/support/network/adapter/pro100/21397.htm
+3. Assign an IP address to the interface by entering the following, where
+   x is the interface number:
 
-For the latest Intel network drivers for Linux, go to:
+     ifconfig 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>
 
-    http://downloadfinder.intel.com/scripts-df/support_intel.asp
 
 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 or insmod command
-using this syntax:
+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>,...]
 
-     insmod ixgb [<option>=<VAL1>,<VAL2>,...]
+For example, with two 10GbE PCI adapters, entering:
 
-For example, with two PRO/10GbE PCI adapters, entering:
+     modprobe ixgb TxDescriptors=80,128
 
-    insmod ixgb TxDescriptors=80,128
-
-loads the ixgb driver with 80 TX resources for the first adapter and 128 TX 
+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. Also, if the driver is statically built into the
-kernel, the driver is loaded with the default values for all the parameters.
-Ethtool can be used to change some of the parameters at runtime.
+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 3
-    This parameter controls the automatic generation(Tx) and response(Rx) to 
-    Ethernet PAUSE frames.
+         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 
+    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 
+    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: 6
-    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 
+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 
+    Increasing this value allows the driver to queue more transmits.  Each
     descriptor is 16 bytes.
 
 XsumRX
@@ -105,51 +162,49 @@ 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.
 
-XsumTX
-Valid Range: 0-1
-Default Value: 1
-    A value of '1' indicates that the driver should enable IP checksum
-    offload for transmitted packets (both UDP and TCP) to the adapter 
-    hardware.
 
 Improving Performance
 =====================
 
-With the Intel PRO/10 GbE adapter, the default Linux configuration will very 
-likely limit the total available throughput artificially.  There is a set of 
-things that when applied together 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.
+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.
+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 ifconfig to modify the mtu (maximum transmission unit) and the txqueuelen 
+- Use ifconfig 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 
+- 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 8086:1048 e6.b=22) may be required to get back to a stable 
-configuration.
+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"
+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
-setpci -d 8086:1048 e6.b=2e
-# set the MTU (max transmission unit) - it requires your switch and clients to change too!
+# 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
 ifconfig eth1 mtu 9000 txqueuelen 1000 up
-# call the sysctl utility to modify /proc/sys entries 
-sysctl -p ./sysctl_ixgb.conf 
+# 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:
@@ -159,54 +214,220 @@ sysctl -p ./sysctl_ixgb.conf
 # several network benchmark tests, your mileage may vary
 
 ### IPV4 specific settings
-net.ipv4.tcp_timestamps = 0 # turns TCP timestamp support off, default 1, reduces CPU use
-net.ipv4.tcp_sack = 0 # turn SACK support off, default on
-# on systems with a VERY fast bus -> memory interface this is the big gainer 
-net.ipv4.tcp_rmem = 10000000 10000000 10000000 # sets min/default/max TCP read buffer, default 4096 87380 174760
-net.ipv4.tcp_wmem = 10000000 10000000 10000000 # sets min/pressure/max TCP write buffer, default 4096 16384 131072
-net.ipv4.tcp_mem = 10000000 10000000 10000000 # sets min/pressure/max TCP buffer space, default 31744 32256 32768
+# 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)
-net.core.rmem_max = 524287 # maximum receive socket buffer size, default 131071
-net.core.wmem_max = 524287 # maximum send socket buffer size, default 131071
-net.core.rmem_default = 524287 # default receive socket buffer size, default 65535
-net.core.wmem_default = 524287 # default send socket buffer size, default 65535
-net.core.optmem_max = 524287 # maximum amount of option memory buffers, default 10240
-net.core.netdev_max_backlog = 300000 # number of unprocessed input packets before kernel starts dropping them, default 300
+# 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.
+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.
+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.
 
-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: 
+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 
+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 ifconfig command to
+  increase the MTU size.  For example:
+
+        ifconfig ethx mtu 9000 up
+
+  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.  Ethtool
+  version 1.6 or later is required for this functionality.
+
+  The latest release of ethtool can be found from
+  http://sourceforge.net/projects/gkernel
+
+  NOTE: Ethtool 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 and support, go to the Intel support website at:
+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 linux.nics@intel.com.
+kernel with a supported adapter, email the specific information related
+to the issue to e1000-devel@lists.sf.net
-- 
2.41.1