From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yongseok Koh Subject: [PATCH v2 2/2] doc: update PMD options for mlx5 Date: Fri, 10 Mar 2017 15:13:34 -0800 Message-ID: <20170310231334.2457-3-yskoh@mellanox.com> References: <20170310231334.2457-1-yskoh@mellanox.com> Mime-Version: 1.0 Content-Type: text/plain Cc: , , , Yongseok Koh To: Return-path: Received: from EUR02-HE1-obe.outbound.protection.outlook.com (mail-eopbgr10046.outbound.protection.outlook.com [40.107.1.46]) by dpdk.org (Postfix) with ESMTP id 0D27C5A8D for ; Sat, 11 Mar 2017 00:13:58 +0100 (CET) In-Reply-To: <20170310231334.2457-1-yskoh@mellanox.com> List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" Enhanced multi-packet send mode is newly introduced for ConnectX-5 families of adaptors. Signed-off-by: Yongseok Koh --- doc/guides/nics/mlx5.rst | 31 +++++++++++++++++++++++++++---- 1 file changed, 27 insertions(+), 4 deletions(-) diff --git a/doc/guides/nics/mlx5.rst b/doc/guides/nics/mlx5.rst index 41f3a472e..0783aebdd 100644 --- a/doc/guides/nics/mlx5.rst +++ b/doc/guides/nics/mlx5.rst @@ -183,10 +183,17 @@ Run-time configuration - ``txq_mpw_en`` parameter [int] - A nonzero value enables multi-packet send. This feature allows the TX - burst function to pack up to five packets in two descriptors in order to - save PCI bandwidth and improve performance at the cost of a slightly - higher CPU usage. + A nonzero value enables multi-packet send (MPS) for ConnectX-4 Lx and + enhanced multi-packet send (Enhanced MPS) for ConnectX-5. MPS allows the + TX burst function to pack up multiple packets in a single descriptor + session in order to save PCI bandwidth and improve performance at the + cost of a slightly higher CPU usage. When ``txq_inline`` is set along + with ``txq_mpw_en``, TX burst function tries to copy entire packet data + on to TX descriptor instead of including pointer of packet only if there + is enough room remained in the descriptor. ``txq_inline`` sets + per-descriptor space for either pointers or inlined packets. In addition, + Enhanced MPS supports hybrid mode - mixing inlined packets and pointers + in the same descriptor. This option cannot be used in conjunction with ``tso`` below. When ``tso`` is set, ``txq_mpw_en`` is disabled. @@ -194,6 +201,22 @@ Run-time configuration It is currently only supported on the ConnectX-4 Lx and ConnectX-5 families of adapters. Enabled by default. +- ``txq_mpw_hdr_dseg_en`` parameter [int] + + A nonzero value enables including two pointers in the first block of TX + descriptor. This can be used to lessen CPU load for memory copy. + + Effective only when Enhanced MPS is supported. Disabled by default. + +- ``txq_max_inline_len`` parameter [int] + + Maximum size of packet to be inlined. This limits the size of packet to + be inlined. If the size of a packet is larger than configured value, the + packet isn't inlined even though there's enough space remained in the + descriptor. Instead, the packet is included with pointer. + + Effective only when Enhanced MPS is supported. The default value is 256. + - ``tso`` parameter [int] A nonzero value enables hardware TSO. -- 2.11.0