From 1db0bcc27c78e9b28ca02bf39d645adf0c1acd76 Mon Sep 17 00:00:00 2001 From: Saeed Mahameed Date: Thu, 23 May 2019 12:55:10 -0700 Subject: [PATCH] net/mlx5e: Disable rxhash when CQE compress is enabled [ Upstream commit c0194e2d0ef0e5ce5e21a35640d23a706827ae28 ] When CQE compression is enabled (Multi-host systems), compressed CQEs might arrive to the driver rx, compressed CQEs don't have a valid hash offload and the driver already reports a hash value of 0 and invalid hash type on the skb for compressed CQEs, but this is not good enough. On a congested PCIe, where CQE compression will kick in aggressively, gro will deliver lots of out of order packets due to the invalid hash and this might cause a serious performance drop. The only valid solution, is to disable rxhash offload at all when CQE compression is favorable (Multi-host systems). Fixes: 7219ab34f184 ("net/mlx5e: CQE compression") Signed-off-by: Saeed Mahameed Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c index b190c44..0f1c296 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c @@ -3734,6 +3734,12 @@ static netdev_features_t mlx5e_fix_features(struct net_device *netdev, netdev_warn(netdev, "Disabling LRO, not supported in legacy RQ\n"); } + if (MLX5E_GET_PFLAG(params, MLX5E_PFLAG_RX_CQE_COMPRESS)) { + features &= ~NETIF_F_RXHASH; + if (netdev->features & NETIF_F_RXHASH) + netdev_warn(netdev, "Disabling rxhash, not supported when CQE compress is active\n"); + } + mutex_unlock(&priv->state_lock); return features; @@ -3860,6 +3866,9 @@ int mlx5e_hwstamp_set(struct mlx5e_priv *priv, struct ifreq *ifr) memcpy(&priv->tstamp, &config, sizeof(config)); mutex_unlock(&priv->state_lock); + /* might need to fix some features */ + netdev_update_features(priv->netdev); + return copy_to_user(ifr->ifr_data, &config, sizeof(config)) ? -EFAULT : 0; } @@ -4702,6 +4711,10 @@ static void mlx5e_build_nic_netdev(struct net_device *netdev) if (!priv->channels.params.scatter_fcs_en) netdev->features &= ~NETIF_F_RXFCS; + /* prefere CQE compression over rxhash */ + if (MLX5E_GET_PFLAG(&priv->channels.params, MLX5E_PFLAG_RX_CQE_COMPRESS)) + netdev->features &= ~NETIF_F_RXHASH; + #define FT_CAP(f) MLX5_CAP_FLOWTABLE(mdev, flow_table_properties_nic_receive.f) if (FT_CAP(flow_modify_en) && FT_CAP(modify_root) && -- 2.7.4