The legacy multi-packet write is the feature allowing to
put multiple packets into one transmitting descriptor,
this feature is supported by only NIC ConnectX-4LX.
The number of packets should be limited to provide
optimal size descriptor and better performance.
Fixes: 18a1c20044c0 ("net/mlx5: implement Tx burst template")
Signed-off-by: Viacheslav Ovsiienko <viachesl...@mellanox.com>
---
drivers/net/mlx5/mlx5_prm.h | 1 +
drivers/net/mlx5/mlx5_rxtx.c | 4 +++-
2 files changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/net/mlx5/mlx5_prm.h b/drivers/net/mlx5/mlx5_prm.h
index 2bac6a7..a805363 100644
--- a/drivers/net/mlx5/mlx5_prm.h
+++ b/drivers/net/mlx5/mlx5_prm.h
@@ -100,6 +100,7 @@
*/
#define MLX5_EMPW_MAX_PACKETS MLX5_TX_COMP_THRESH
#define MLX5_MPW_MAX_PACKETS 6
+#define MLX5_MPW_INLINE_MAX_PACKETS 2
/*
* Default packet length threshold to be inlined with
diff --git a/drivers/net/mlx5/mlx5_rxtx.c b/drivers/net/mlx5/mlx5_rxtx.c
index 25d915c..acf0fd7 100644
--- a/drivers/net/mlx5/mlx5_rxtx.c
+++ b/drivers/net/mlx5/mlx5_rxtx.c
@@ -4059,7 +4059,9 @@ enum mlx5_txcmp_code {
* Limits the amount of packets in one WQE
* to improve CQE latency generation.
*/
- nlim = RTE_MIN(pkts_n, MLX5_EMPW_MAX_PACKETS);
+ nlim = RTE_MIN(pkts_n, MLX5_TXOFF_CONFIG(MPW) ?
+ MLX5_MPW_INLINE_MAX_PACKETS :
+ MLX5_EMPW_MAX_PACKETS);
/* Check whether we have minimal amount WQEs */
if (unlikely(loc->wqe_free <
((2 + MLX5_EMPW_MIN_PACKETS + 3) / 4)))
--
1.8.3.1
