[dpdk-dev] [PATCH v2 2/2] net/mlx5: add Rx and Tx tuning parameters

[Shahaf Shuler <shahafs@mellanox.com>]

A new ethdev API was exposed by
commit 3be82f5cc5e3 ("ethdev: support PMD-tuned Tx/Rx parameters")

Enabling the PMD to provide default parameters in case no strict request
from application in order to improve the out of the box experience.

While the current API lacks the means for the PMD to provide the best
possible value, providing the best default the PMD can guess.
The values are based on Mellanox performance report and depends on the
underlying NIC capabilities.

Cc: erezsc@mellanox.com
Cc: amira@mellanox.com
Cc: olgas@mellanox.com

Signed-off-by: Shahaf Shuler <shahafs@mellanox.com>
---

On v2:
 - refactor the code to ease the maintenance.

---
 drivers/net/mlx5/mlx5_ethdev.c | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/drivers/net/mlx5/mlx5_ethdev.c b/drivers/net/mlx5/mlx5_ethdev.c
index 588d4ba627..3fad199a60 100644
--- a/drivers/net/mlx5/mlx5_ethdev.c
+++ b/drivers/net/mlx5/mlx5_ethdev.c
@@ -417,6 +417,45 @@ mlx5_dev_configure(struct rte_eth_dev *dev)
 }
 
 /**
+ * Sets default tuning parameters.
+ *
+ * @param dev
+ *   Pointer to Ethernet device.
+ * @param[out] info
+ *   Info structure output buffer.
+ */
+static void
+mlx5_set_default_params(struct rte_eth_dev *dev, struct rte_eth_dev_info *info)
+{
+	struct priv *priv = dev->data->dev_private;
+
+	/* Minimum CPU utilization. */
+	info->default_rxportconf.ring_size = 256;
+	info->default_txportconf.ring_size = 256;
+	info->default_rxportconf.burst_size = 64;
+	info->default_txportconf.burst_size = 64;
+	if (priv->link_speed_capa & ETH_LINK_SPEED_100G) {
+		info->default_rxportconf.nb_queues = 16;
+		info->default_txportconf.nb_queues = 16;
+		if (dev->data->nb_rx_queues > 2 ||
+		    dev->data->nb_tx_queues > 2) {
+			/* Max Throughput. */
+			info->default_rxportconf.ring_size = 2048;
+			info->default_txportconf.ring_size = 2048;
+		}
+	} else {
+		info->default_rxportconf.nb_queues = 8;
+		info->default_txportconf.nb_queues = 8;
+		if (dev->data->nb_rx_queues > 2 ||
+		    dev->data->nb_tx_queues > 2) {
+			/* Max Throughput. */
+			info->default_rxportconf.ring_size = 4096;
+			info->default_txportconf.ring_size = 4096;
+		}
+	}
+}
+
+/**
  * DPDK callback to get information about the device.
  *
  * @param dev
@@ -458,6 +497,7 @@ mlx5_dev_infos_get(struct rte_eth_dev *dev, struct rte_eth_dev_info *info)
 	info->hash_key_size = rss_hash_default_key_len;
 	info->speed_capa = priv->link_speed_capa;
 	info->flow_type_rss_offloads = ~MLX5_RSS_HF_MASK;
+	mlx5_set_default_params(dev, info);
 }
 
 /**
-- 
2.12.0