mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 19:00:25 +00:00
![Linus Torvalds](/assets/img/avatar_default.png)
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
212 lines
8.5 KiB
Text
212 lines
8.5 KiB
Text
Linux* Base Driver for the Intel(R) PRO/10GbE Family of Adapters
|
|
================================================================
|
|
|
|
November 17, 2004
|
|
|
|
|
|
Contents
|
|
========
|
|
|
|
- In This Release
|
|
- Identifying Your Adapter
|
|
- Command Line Parameters
|
|
- Improving Performance
|
|
- Support
|
|
|
|
|
|
In This Release
|
|
===============
|
|
|
|
This file describes the Linux* Base Driver for the Intel(R) PRO/10GbE Family
|
|
of Adapters, version 1.0.x.
|
|
|
|
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.
|
|
|
|
Use the above information and the Adapter & Driver ID Guide at:
|
|
|
|
http://support.intel.com/support/network/adapter/pro100/21397.htm
|
|
|
|
For the latest Intel network drivers for Linux, go to:
|
|
|
|
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:
|
|
|
|
modprobe ixgb [<option>=<VAL1>,<VAL2>,...]
|
|
|
|
insmod ixgb [<option>=<VAL1>,<VAL2>,...]
|
|
|
|
For example, with two PRO/10GbE PCI adapters, entering:
|
|
|
|
insmod 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. 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.
|
|
|
|
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.
|
|
|
|
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: 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
|
|
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.
|
|
|
|
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.
|
|
|
|
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
|
|
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 8086:1048 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"
|
|
# 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!
|
|
# 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
|
|
- 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
|
|
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
|
|
|
|
### 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
|
|
- END sysctl_ixgb.conf
|
|
|
|
Edit the ixgb_perf.sh script if necessary to change eth1 to whatever interface
|
|
your ixgb driver is using.
|
|
|
|
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.
|
|
|
|
Support
|
|
=======
|
|
|
|
For general information and support, go to the Intel support website at:
|
|
|
|
http://support.intel.com
|
|
|
|
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.
|