net/mlx4_en: Optimized single ring steering
Avoid touching RX QP RSS context when loading with only
one RX ring, to allow optimized A0 RX steering.
Enable by:
- loading mlx4_core with module param: log_num_mgm_entry_size = -6.
- then: ethtool -L <interface> rx 1
Performance tests:
Tested on ConnectX3Pro, Intel(R) Xeon(R) CPU E5-2680 v3 @ 2.50GHz
XDP_DROP packet rate:
-------------------------------------
| Before | After | Gain |
IPv4 | 20.5 Mpps | 28.1 Mpps | 37% |
IPv6 | 18.4 Mpps | 28.1 Mpps | 53% |
-------------------------------------
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Cc: kernel-team@fb.com
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_main.c b/drivers/net/ethernet/mellanox/mlx4/en_main.c
index d94f981..56cdf38 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_main.c
@@ -125,9 +125,9 @@ void mlx4_en_update_loopback_state(struct net_device *dev,
priv->flags |= MLX4_EN_FLAG_ENABLE_HW_LOOPBACK;
mutex_lock(&priv->mdev->state_lock);
- if (priv->mdev->dev->caps.flags2 &
- MLX4_DEV_CAP_FLAG2_UPDATE_QP_SRC_CHECK_LB &&
- priv->rss_map.indir_qp.qpn) {
+ if ((priv->mdev->dev->caps.flags2 &
+ MLX4_DEV_CAP_FLAG2_UPDATE_QP_SRC_CHECK_LB) &&
+ priv->rss_map.indir_qp && priv->rss_map.indir_qp->qpn) {
int i;
int err = 0;
int loopback = !!(features & NETIF_F_LOOPBACK);