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authorOlga Shern <>2015-11-23 15:44:49 +0100
committerThomas Monjalon <>2015-11-24 17:49:27 +0100
commit28014f0754860f06e7504510496d7b7c9b235d88 (patch)
treec38a44bf92f2745edec84b8174f14fc53b900bf5 /doc
parente9d39be873d710e1b5d1ccf6926eca44475a6f34 (diff)
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 <>
Diffstat (limited to 'doc')
1 files changed, 13 insertions, 0 deletions
diff --git a/doc/guides/nics/mlx5.rst b/doc/guides/nics/mlx5.rst
index 2d68914..eb8c042 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
+ 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