QoS Configuration
To learn more about port QoS configuration, refer to this community post.
When working in Embedded Host mode, using mlnx_qos on both the host and Arm will result with undefined behavior. Users must only use mlnx_qos from the Arm. After changing the QoS settings from Arm, users must restart the mlx5 driver on host.
When configuring QoS using DCBX, the lldpad service from the DPU side must be disabled if the configurations are not done using tools other than lldpad.
This section explains how to configure QoS group and settings using devlink located under /opt/mellanox/iproute2/sbin/. It is applicable to host PF/VF and Arm side SFs. The following uses VF as example.
The settings of a QoS group include creating/deleting a QoS group and modifying its tx_max and tx_share values. The settings of VF QoS include modifying its tx_max and tx_share values, assigning a VF to a QoS group, and unassigning a VF from a QoS group. This section focuses on the configuration syntax.
Please refer to section "Limit and Bandwidth Share Per VF" in the MLNX_OFED User Manual for detailed explanation on vPort QoS behaviors.
devlink port function rate add <DEV>/<GROUP_NAME> Adds a QoS group. |
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Syntax Description |
DEV/GROUP_NAME |
Specifies group name in string format |
Example |
This command adds a new QoS group named "12_group" under device "pci/0000:03:00.0":
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Notes |
devlink port function rate del <DEV>/<GROUP_NAME> Deletes a QoS group. |
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Syntax Description |
DEV/GROUP_NAME |
Specifies group name in string format |
Example |
This command deletes QoS group "12_group" from device "pci/0000:03:00.0":
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Notes |
devlink port function rate set {<DEV>/<GROUP_NAME> | <DEV>/<PORT_INDEX>} tx_max <TX_MAX> [tx_share <TX_SHARE>] Sets tx_max and tx_share for QoS group or devlink port. |
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Syntax Description |
DEV/GROUP_NAME |
Specifies the group name to operate on |
DEV/PORT_INDEX |
Specifies the devlink port to operate on |
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TX_MAX |
tx_max bandwidth in Mb/s |
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TX_SHARE |
tx_share bandwidth in Mb/s |
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Example |
This command sets tx_max to 2000Mb/s and tx_share to 500Mb/s for the "12_group" QoS group:
This command sets tx_max to 2000Mb/s and tx_share to 500Mb/s for the VF represented by port index 196609:
This command displays a mapping between VF devlink ports and netdev names:
In the output of this command, VFs are indicated by flavour pcivf. |
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Notes |
devlink port function rate set <DEV>/<PORT_INDEX> {parent <PARENT_GROUP_NAME>} Assigns devlink port to a QoS group. |
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Syntax Description |
DEV/PORT_INDEX |
Specifies the devlink port to operate on |
PARENT_GROUP_NAME |
parent group name in string format |
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Example |
This command assigns this function to the QoS group "12_group":
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Notes |
devlink port function rate set noparent
devlink port function rate set <DEV>/<PORT_INDEX> noparent Ungroups a devlink port. |
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Syntax Description |
DEV/PORT_INDEX |
Specifies the devlink port to operate on |
Example |
This command ungroups this function:
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Notes |
devlink port function rate show [<DEV>/<GROUP_NAME> | <DEV>/<PORT_INDEX>] Displays QoS information QoS group or devlink port. |
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Syntax Description |
DEV/GROUP_NAME |
Specifies the group name to display |
DEV/PORT_INDEX |
Specifies the devlink port to display |
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Example |
This command displays the QoS info of all QoS groups and devlink ports on the system:
This command displays QoS info of 12_group:
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Notes |
If a QoS group name or devlink port are not specified, all QoS groups and devlink ports are displayed. |