From 0f6e4cf67411631be7f010fdb5c2d82c0c8705c0 Mon Sep 17 00:00:00 2001 From: Eran Ben Elisha Date: Wed, 26 Apr 2017 13:42:04 +0300 Subject: [PATCH] net/mlx5e: Disable HW LRO when PCI is slower than link on striding RQ We will activate the HW LRO only on servers with PCI BW > MAX LINK BW, or when PCI BW > 16Gbps. On other cases we do not want LRO by default as LRO sessions might get timeout and add redundant software overhead. Tested: ethtool -k | grep large-receive-offload On systems with and without the limitations. Signed-off-by: Eran Ben Elisha Cc: kernel-team@fb.com Signed-off-by: Saeed Mahameed --- .../net/ethernet/mellanox/mlx5/core/en_main.c | 21 ++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c index 1afaca96a30d..a61b71b6fff3 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c @@ -3785,6 +3785,12 @@ static bool cqe_compress_heuristic(u32 link_speed, u32 pci_bw) (pci_bw < 40000) && (pci_bw < link_speed)); } +static bool hw_lro_heuristic(u32 link_speed, u32 pci_bw) +{ + return !(link_speed && pci_bw && + (pci_bw <= 16000) && (pci_bw < link_speed)); +} + void mlx5e_set_rx_cq_mode_params(struct mlx5e_params *params, u8 cq_period_mode) { params->rx_cq_period_mode = cq_period_mode; @@ -3829,6 +3835,11 @@ void mlx5e_build_nic_params(struct mlx5_core_dev *mdev, params->num_channels = max_channels; params->num_tc = 1; + mlx5e_get_max_linkspeed(mdev, &link_speed); + mlx5e_get_pci_bw(mdev, &pci_bw); + mlx5_core_dbg(mdev, "Max link speed = %d, PCI BW = %d\n", + link_speed, pci_bw); + /* SQ */ params->log_sq_size = is_kdump_kernel() ? MLX5E_PARAMS_MINIMUM_LOG_SQ_SIZE : @@ -3837,13 +3848,9 @@ void mlx5e_build_nic_params(struct mlx5_core_dev *mdev, /* set CQE compression */ params->rx_cqe_compress_def = false; if (MLX5_CAP_GEN(mdev, cqe_compression) && - MLX5_CAP_GEN(mdev, vport_group_manager)) { - mlx5e_get_max_linkspeed(mdev, &link_speed); - mlx5e_get_pci_bw(mdev, &pci_bw); - mlx5_core_dbg(mdev, "Max link speed = %d, PCI BW = %d\n", - link_speed, pci_bw); + MLX5_CAP_GEN(mdev, vport_group_manager)) params->rx_cqe_compress_def = cqe_compress_heuristic(link_speed, pci_bw); - } + MLX5E_SET_PFLAG(params, MLX5E_PFLAG_RX_CQE_COMPRESS, params->rx_cqe_compress_def); /* RQ */ @@ -3852,7 +3859,7 @@ void mlx5e_build_nic_params(struct mlx5_core_dev *mdev, /* HW LRO */ /* TODO: && MLX5_CAP_ETH(mdev, lro_cap) */ if (params->rq_wq_type == MLX5_WQ_TYPE_LINKED_LIST_STRIDING_RQ) - params->lro_en = true; + params->lro_en = hw_lro_heuristic(link_speed, pci_bw); params->lro_timeout = mlx5e_choose_lro_timeout(mdev, MLX5E_DEFAULT_LRO_TIMEOUT); /* CQ moderation params */ -- 2.20.1