net/mlx5e: Slightly reduce hardware LRO size

Before this patch LRO size was 64K, now with build_skb requires
extra room, headroom + sizeof(skb_shared_info) added to the data
buffer will make  wqe size or page_frag_size slightly larger than
64K which will demand order 5 page instead of order 4 in 4K page systems.

We take those extra bytes from hardware LRO data size in order to not
increase the required page order for when hardware LRO is enabled.

Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index f2efa53..8734240 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -3187,8 +3187,11 @@ static void mlx5e_build_nic_netdev_priv(struct mlx5_core_dev *mdev,
        mlx5e_build_default_indir_rqt(mdev, priv->params.indirection_rqt,
                                      MLX5E_INDIR_RQT_SIZE, profile->max_nch(mdev));
 
-       priv->params.lro_wqe_sz            =
-               MLX5E_PARAMS_DEFAULT_LRO_WQE_SZ;
+       priv->params.lro_wqe_sz =
+               MLX5E_PARAMS_DEFAULT_LRO_WQE_SZ -
+               /* Extra room needed for build_skb */
+               MLX5_RX_HEADROOM -
+               SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 
        /* Initialize pflags */
        MLX5E_SET_PRIV_FLAG(priv, MLX5E_PFLAG_RX_CQE_BASED_MODER,