From: Olga Shern Date: Mon, 23 Nov 2015 14:44:49 +0000 (+0100) Subject: mlx5: add environment variables section to documentation X-Git-Tag: spdx-start~7981 X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=28014f0754860f06e7504510496d7b7c9b235d88;p=dpdk.git mlx5: add environment variables section to documentation Describe how applications can benefit from CQE compression. Signed-off-by: Olga Shern Signed-off-by: Adrien Mazarguil --- diff --git a/doc/guides/nics/mlx5.rst b/doc/guides/nics/mlx5.rst index 2d68914408..eb8c042076 100644 --- a/doc/guides/nics/mlx5.rst +++ b/doc/guides/nics/mlx5.rst @@ -130,6 +130,19 @@ These options can be modified in the ``.config`` file. This value is always 1 for RX queues since they use a single MP. +Environment variables +~~~~~~~~~~~~~~~~~~~~~ + +- ``MLX5_ENABLE_CQE_COMPRESSION`` + + A nonzero value lets ConnectX-4 return smaller completion entries to + improve performance when PCI backpressure is detected. It is most useful + for scenarios involving heavy traffic on many queues. + + Since the additional software logic necessary to handle this mode can + lower performance when there is no backpressure, it is not enabled by + default. + Run-time configuration ~~~~~~~~~~~~~~~~~~~~~~