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diff --git a/kernel/Documentation/networking/ixgb.txt b/kernel/Documentation/networking/ixgb.txt new file mode 100644 index 000000000..9b4a10a1c --- /dev/null +++ b/kernel/Documentation/networking/ixgb.txt @@ -0,0 +1,433 @@ +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 + http://ftp.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 |