[dpdk-dev,14/14] mlx5: add environment variables section to documentation
Commit Message
From: Olga Shern <olgas@mellanox.com>
Describe how applications can benefit from CQE compression.
Signed-off-by: Olga Shern <olgas@mellanox.com>
Signed-off-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>
---
doc/guides/nics/mlx5.rst | 13 +++++++++++++
1 file changed, 13 insertions(+)
@@ -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
~~~~~~~~~~~~~~~~~~~~~~