From: Saeed Mahameed saeedm@mellanox.com
[ 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 saeedm@mellanox.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c @@ -3750,6 +3750,12 @@ static netdev_features_t mlx5e_fix_featu 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; @@ -3875,6 +3881,9 @@ int mlx5e_hwstamp_set(struct mlx5e_priv 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; } @@ -4734,6 +4743,10 @@ static void mlx5e_build_nic_netdev(struc 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) &&