Intel idpf Linux driver. Copyright(C) 2023 Intel Corporation.
The idpf driver serves as both the Physical Function (PF) and Virtual Function (VF) driver for the Intel(R) Infrastructure Data Path Function.
Driver information can be obtained using ethtool, lspci, and ip.
For questions related to hardware requirements, refer to the documentation supplied with your Intel adapter. All hardware requirements listed apply to use with Linux.
For information on how to identify your adapter, and for the latest Intel network drivers, refer to the Intel Support website: http://www.intel.com/support
The driver utilizes the ethtool interface for driver configuration and diagnostics, as well as displaying statistical information. The latest ethtool version is required for this functionality. If you don't have one yet, you can obtain it at: https://kernel.org/pub/software/network/ethtool/
Jumbo Frames support is enabled by changing the Maximum Transmission Unit (MTU) to a value larger than the default value of 1500.
Use the ip command to increase the MTU size. For example, enter the following where <ethX> is the interface number:
# ip link set mtu 9000 dev <ethX>
# ip link set up dev <ethX>
The maximum MTU setting for jumbo frames is 9706. This corresponds to the maximum jumbo frame size of 9728 bytes.
This driver will attempt to use multiple page sized buffers to receive each jumbo packet. This should help to avoid buffer starvation issues when allocating receive packets.
Packet loss may have a greater impact on throughput when you use jumbo frames. If you observe a drop in performance after enabling jumbo frames, enabling flow control may mitigate the issue.
Driver defaults are meant to fit a wide variety of workloads, but if further optimization is required, we recommend experimenting with the following settings.
This driver supports an adaptive interrupt throttle rate (ITR) mechanism that is tuned for general workloads. The user can customize the interrupt rate control for specific workloads, via ethtool, adjusting the number of microseconds between interrupts.
To set the interrupt rate manually, you must disable adaptive mode:
# ethtool -C <ethX> adaptive-rx off adaptive-tx off
- For lower CPU utilization:
Disable adaptive ITR and lower Rx and Tx interrupts. The examples below affect every queue of the specified interface.
Setting rx-usecs and tx-usecs to 80 will limit interrupts to about 12,500 interrupts per second per queue:
# ethtool -C <ethX> adaptive-rx off adaptive-tx off rx-usecs 80 tx-usecs 80
- For reduced latency:
Disable adaptive ITR and ITR by setting rx-usecs and tx-usecs to 0 using ethtool:
# ethtool -C <ethX> adaptive-rx off adaptive-tx off rx-usecs 0 tx-usecs 0
- Per-queue interrupt rate settings:
The following examples are for queues 1 and 3, but you can adjust other queues.
To disable Rx adaptive ITR and set static Rx ITR to 10 microseconds or about 100,000 interrupts/second, for queues 1 and 3:
# ethtool --per-queue <ethX> queue_mask 0xa --coalesce adaptive-rx off rx-usecs 10
To show the current coalesce settings for queues 1 and 3:
# ethtool --per-queue <ethX> queue_mask 0xa --show-coalesce
In addition to the other suggestions in this section, the following may be helpful to optimize performance in VMs.
Using the appropriate mechanism (vcpupin) in the VM, pin the CPUs to individual LCPUs, making sure to use a set of CPUs included in the device's local_cpulist: /sys/class/net/<ethX>/device/local_cpulist.
Configure as many Rx/Tx queues in the VM as available. (See the idpf driver documentation for the number of queues supported.) For example:# ethtool -L <virt_interface> rx <max> tx <max>
For general information, go to the Intel support website at: http://www.intel.com/support/
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 firstname.lastname@example.org.
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