path: root/doc/guides/nics/mlx5.rst
diff options
authorViacheslav Ovsiienko <>2019-08-08 11:47:23 +0000
committerThomas Monjalon <>2019-08-08 16:53:49 +0200
commit3a418d1d3d8561c1de4bfc7c05fc4c975aa1a0b1 (patch)
treeebac75a5f0ddee861cf8738f9f14128b7e995ea4 /doc/guides/nics/mlx5.rst
parente98e44bace69ebd28ac4c723c33c2c0985fb0c76 (diff)
doc: add limitation with mlx5 Tx inline settings
Introduces the possible limitations on maximal Tx queue size in descriptors if Tx inline data are enabled. Signed-off-by: Viacheslav Ovsiienko <>
Diffstat (limited to 'doc/guides/nics/mlx5.rst')
1 files changed, 10 insertions, 0 deletions
diff --git a/doc/guides/nics/mlx5.rst b/doc/guides/nics/mlx5.rst
index d6082ac..4115520 100644
--- a/doc/guides/nics/mlx5.rst
+++ b/doc/guides/nics/mlx5.rst
@@ -162,6 +162,12 @@ Limitations
To receive IPv6 Multicast messages on VM, explicitly set the relevant
MAC address using rte_eth_dev_mac_addr_add() API.
+- The amount of descriptors in Tx queue may be limited by data inline settings.
+ Inline data require the more descriptor building blocks and overall block
+ amount may exceed the hardware supported limits. The application should
+ reduce the requested Tx size or adjust data inline settings with
+ ``txq_inline_max`` and ``txq_inline_mpw`` devargs keys.
- E-Switch decapsulation Flow:
- can be applied to PF port only.
@@ -400,6 +406,10 @@ Run-time configuration
option should be used with care, as it may lower performance when back
pressure is not expected.
+ If inline data are enabled it may affect the maximal size of Tx queue in
+ descriptors because the inline data increase the descriptor size and
+ queue size limits supported by hardware may be exceeded.
- ``txq_inline_min`` parameter [int]
Minimal amount of data to be inlined into WQE during Tx operations. NICs