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Diffstat (limited to 'doc/guides/nics/mlx5.rst')
| -rw-r--r-- | doc/guides/nics/mlx5.rst | 35 |
1 files changed, 34 insertions, 1 deletions
diff --git a/doc/guides/nics/mlx5.rst b/doc/guides/nics/mlx5.rst index 67696283..7af5ead8 100644 --- a/doc/guides/nics/mlx5.rst +++ b/doc/guides/nics/mlx5.rst @@ -54,6 +54,7 @@ Features - Support for scattered TX and RX frames. - IPv4, IPv6, TCPv4, TCPv6, UDPv4 and UDPv6 RSS on any number of queues. - Several RSS hash keys, one for each flow type. +- Default RSS operation with no hash key specification. - Configurable RETA table. - Support for multiple MAC addresses. - VLAN filtering. @@ -246,6 +247,24 @@ Run-time configuration - x86_64 with ConnectX-4, ConnectX-4 LX, ConnectX-5 and Bluefield. - POWER8 and ARMv8 with ConnectX-4 LX, ConnectX-5 and Bluefield. +- ``rxq_cqe_pad_en`` parameter [int] + + A nonzero value enables 128B padding of CQE on RX side. The size of CQE + is aligned with the size of a cacheline of the core. If cacheline size is + 128B, the CQE size is configured to be 128B even though the device writes + only 64B data on the cacheline. This is to avoid unnecessary cache + invalidation by device's two consecutive writes on to one cacheline. + However in some architecture, it is more beneficial to update entire + cacheline with padding the rest 64B rather than striding because + read-modify-write could drop performance a lot. On the other hand, + writing extra data will consume more PCIe bandwidth and could also drop + the maximum throughput. It is recommended to empirically set this + parameter. Disabled by default. + + Supported on: + + - CPU having 128B cacheline with ConnectX-5 and Bluefield. + - ``mprq_en`` parameter [int] A nonzero value enables configuring Multi-Packet Rx queues. Rx queue is @@ -320,6 +339,20 @@ Run-time configuration - Set to 8 by default. +- ``txqs_max_vec`` parameter [int] + + Enable vectorized Tx only when the number of TX queues is less than or + equal to this value. Effective only when ``tx_vec_en`` is enabled. + + On ConnectX-5: + + - Set to 8 by default on ARMv8. + - Set to 4 by default otherwise. + + On Bluefield + + - Set to 16 by default. + - ``txq_mpw_en`` parameter [int] A nonzero value enables multi-packet send (MPS) for ConnectX-4 Lx and @@ -365,7 +398,7 @@ Run-time configuration - ``tx_vec_en`` parameter [int] A nonzero value enables Tx vector on ConnectX-5 and Bluefield NICs if the number of - global Tx queues on the port is lesser than MLX5_VPMD_MIN_TXQS. + global Tx queues on the port is less than ``txqs_max_vec``. This option cannot be used with certain offloads such as ``DEV_TX_OFFLOAD_TCP_TSO, DEV_TX_OFFLOAD_VXLAN_TNL_TSO, DEV_TX_OFFLOAD_GRE_TNL_TSO, DEV_TX_OFFLOAD_VLAN_INSERT``. |