From dffc3e9be320a7a71d93f9e0ce6984fb05066480 Mon Sep 17 00:00:00 2001 From: Ciara Loftus Date: Tue, 22 Feb 2022 14:31:48 +0000 Subject: [PATCH] doc: add AF_XDP queue setup information When an AF_XDP PMD is created without specifying the 'start_queue', the default Rx queue associated with the socket will be Rx queue 0. A common scenario encountered by users new to AF_XDP is that they create the socket on queue 0 however their interface is configured with many more queues. In this case, traffic might land on for example queue 18 which means it will never reach the socket. This commit updates the AF_XDP documentation with instructions on how to configure the interface to ensure the traffic will land on queue 0 and thus reach the socket successfully. Signed-off-by: Ciara Loftus Acked-by: Ferruh Yigit --- doc/guides/nics/af_xdp.rst | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/doc/guides/nics/af_xdp.rst b/doc/guides/nics/af_xdp.rst index ee1e146a9e..56681c8365 100644 --- a/doc/guides/nics/af_xdp.rst +++ b/doc/guides/nics/af_xdp.rst @@ -64,6 +64,18 @@ The following example will set up an af_xdp interface in DPDK: --vdev net_af_xdp,iface=ens786f1 +If 'start_queue' is not specified in the vdev arguments, +the socket will by default be created on Rx queue 0. +To ensure traffic lands on this queue, +one can use flow steering if the network card supports it. +Or, a simpler way is to reduce the number of configured queues +for the device which will ensure that all traffic will land on queue 0 +and thus reach the socket: + +.. code-block:: console + + ethtool -L ens786f1 combined 1 + Limitations ----------- -- 2.39.5