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5.2 KiB
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161 lines
5.2 KiB
ReStructuredText
.. SPDX-License-Identifier: GPL-2.0+
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==========================================================================
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idpf Linux* Base Driver for the Intel(R) Infrastructure Data Path Function
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==========================================================================
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Intel idpf Linux driver.
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Copyright(C) 2023 Intel Corporation.
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.. contents::
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The idpf driver serves as both the Physical Function (PF) and Virtual Function
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(VF) driver for the Intel(R) Infrastructure Data Path Function.
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Driver information can be obtained using ethtool, lspci, and ip.
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For questions related to hardware requirements, refer to the documentation
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supplied with your Intel adapter. All hardware requirements listed apply to use
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with Linux.
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Identifying Your Adapter
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========================
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For information on how to identify your adapter, and for the latest Intel
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network drivers, refer to the Intel Support website:
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http://www.intel.com/support
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Additional Features and Configurations
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======================================
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ethtool
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-------
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The driver utilizes the ethtool interface for driver configuration and
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diagnostics, as well as displaying statistical information. The latest ethtool
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version is required for this functionality. If you don't have one yet, you can
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obtain it at:
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https://kernel.org/pub/software/network/ethtool/
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Viewing Link Messages
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---------------------
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Link messages will not be displayed to the console if the distribution is
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restricting system messages. In order to see network driver link messages on
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your console, set dmesg to eight by entering the following::
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# dmesg -n 8
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.. note::
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This setting is not saved across reboots.
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Jumbo Frames
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------------
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Jumbo Frames support is enabled by changing the Maximum Transmission Unit (MTU)
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to a value larger than the default value of 1500.
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Use the ip command to increase the MTU size. For example, enter the following
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where <ethX> is the interface number::
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# ip link set mtu 9000 dev <ethX>
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# ip link set up dev <ethX>
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.. note::
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The maximum MTU setting for jumbo frames is 9706. This corresponds to the
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maximum jumbo frame size of 9728 bytes.
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.. note::
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This driver will attempt to use multiple page sized buffers to receive
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each jumbo packet. This should help to avoid buffer starvation issues when
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allocating receive packets.
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.. note::
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Packet loss may have a greater impact on throughput when you use jumbo
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frames. If you observe a drop in performance after enabling jumbo frames,
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enabling flow control may mitigate the issue.
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Performance Optimization
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========================
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Driver defaults are meant to fit a wide variety of workloads, but if further
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optimization is required, we recommend experimenting with the following
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settings.
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Interrupt Rate Limiting
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-----------------------
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This driver supports an adaptive interrupt throttle rate (ITR) mechanism that
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is tuned for general workloads. The user can customize the interrupt rate
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control for specific workloads, via ethtool, adjusting the number of
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microseconds between interrupts.
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To set the interrupt rate manually, you must disable adaptive mode::
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# ethtool -C <ethX> adaptive-rx off adaptive-tx off
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For lower CPU utilization:
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- Disable adaptive ITR and lower Rx and Tx interrupts. The examples below
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affect every queue of the specified interface.
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- Setting rx-usecs and tx-usecs to 80 will limit interrupts to about
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12,500 interrupts per second per queue::
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# ethtool -C <ethX> adaptive-rx off adaptive-tx off rx-usecs 80
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tx-usecs 80
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For reduced latency:
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- Disable adaptive ITR and ITR by setting rx-usecs and tx-usecs to 0
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using ethtool::
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# ethtool -C <ethX> adaptive-rx off adaptive-tx off rx-usecs 0
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tx-usecs 0
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Per-queue interrupt rate settings:
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- The following examples are for queues 1 and 3, but you can adjust other
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queues.
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- To disable Rx adaptive ITR and set static Rx ITR to 10 microseconds or
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about 100,000 interrupts/second, for queues 1 and 3::
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# ethtool --per-queue <ethX> queue_mask 0xa --coalesce adaptive-rx off
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rx-usecs 10
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- To show the current coalesce settings for queues 1 and 3::
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# ethtool --per-queue <ethX> queue_mask 0xa --show-coalesce
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Virtualized Environments
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------------------------
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In addition to the other suggestions in this section, the following may be
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helpful to optimize performance in VMs.
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- Using the appropriate mechanism (vcpupin) in the VM, pin the CPUs to
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individual LCPUs, making sure to use a set of CPUs included in the
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device's local_cpulist: /sys/class/net/<ethX>/device/local_cpulist.
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- Configure as many Rx/Tx queues in the VM as available. (See the idpf driver
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documentation for the number of queues supported.) For example::
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# ethtool -L <virt_interface> rx <max> tx <max>
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Support
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=======
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For general information, go to the Intel support website at:
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http://www.intel.com/support/
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If an issue is identified with the released source code on a supported kernel
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with a supported adapter, email the specific information related to the issue
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to intel-wired-lan@lists.osuosl.org.
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Trademarks
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==========
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Intel is a trademark or registered trademark of Intel Corporation or its
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subsidiaries in the United States and/or other countries.
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* Other names and brands may be claimed as the property of others.
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