net/mlx5e: Increase VF representors' SQ size to 128

The default size for the VF representors' SQ was too small to handle high
packet rates. Doubling the size from 64 to 128 drastically improves the
packet rate under stress (by about 50%), whereas increasing the size
beyond 128 has not shown to make any further difference.

The impact of the SQ size was measured with UDP traffic, in the following
topology: TG <-> PF <-> TC forwarding <-> VF representor <-> VF in VM
over a single core processing bi-directional traffic, with the following
results:

                                  SQ size of 64:     SQ size of 128:
Packet rate for 64B UDP packets:    860 [Kpps]         1280 [Kpps]
Packet rate for 114B VxLan
encapsulated UDP packets:           320 [Kpps]          500 [Kpps]
Signed-off-by: NGavi Teitz <gavi@mellanox.com>
Reviewed-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

drivers/net/ethernet/mellanox/mlx5/core/en_rep.c

@@ -45,8 +45,8 @@
 #include "en/tc_tun.h"
 #include "fs_core.h"
 
-#define MLX5E_REP_PARAMS_LOG_SQ_SIZE \
-	max(0x6, MLX5E_PARAMS_MINIMUM_LOG_SQ_SIZE)
+#define MLX5E_REP_PARAMS_DEF_LOG_SQ_SIZE \
+	max(0x7, MLX5E_PARAMS_MINIMUM_LOG_SQ_SIZE)
 
 static const char mlx5e_rep_driver_name[] = "mlx5e_rep";
 
@@ -1336,7 +1336,7 @@ static void mlx5e_build_rep_params(struct net_device *netdev)
 	if (rep->vport == FDB_UPLINK_VPORT)
 		params->log_sq_size = MLX5E_PARAMS_DEFAULT_LOG_SQ_SIZE;
 	else
-		params->log_sq_size = MLX5E_REP_PARAMS_LOG_SQ_SIZE;
+		params->log_sq_size = MLX5E_REP_PARAMS_DEF_LOG_SQ_SIZE;;
 
 	/* RQ */
 	mlx5e_build_rq_params(mdev, params);