From: Dragos Tatulea Allow high order pages only when SHAMPO mode is enabled (hw-gro) and the queue is used for zerocopy (has memory provider ops set). The limit is 128K and it was chosen for the following reasons: - 256K size requires a special case during MTT calculation to split the page in two. That's because two MTTs are needed to form an octword. - Higher sizes require increasing WQE size and/or reducing the number of WQEs. - Having the RQ lined with too few large pages can lead to refill issues. Results show an increase in BW and a decrease in CPU usage. The benchmark was done with the zcrx samples from liburing [0]. rx_buf_len=4K, oncpu [1]: packets=3358832 (MB=820027), rps=55794 (MB/s=13621) Average: CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle Average: 9 1.56 0.00 18.09 13.42 0.00 66.80 0.00 0.00 0.00 0.12 rx_buf_len=128K, oncpu [2]: packets=3781376 (MB=923187), rps=62813 (MB/s=15335) Average: CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle Average: 9 0.33 0.00 7.61 18.86 0.00 73.08 0.00 0.00 0.00 0.12 rx_buf_len=4K, offcpu [3]: packets=3460368 (MB=844816), rps=57481 (MB/s=14033) Average: CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle Average: 9 0.00 0.00 0.26 0.00 0.00 92.63 0.00 0.00 0.00 7.11 Average: 11 3.04 0.00 68.09 28.87 0.00 0.00 0.00 0.00 0.00 0.00 rx_buf_len=128K, offcpu [4]: packets=4119840 (MB=1005820), rps=68435 (MB/s=16707) Average: CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle Average: 9 0.00 0.00 0.87 0.00 0.00 63.77 0.00 0.00 0.00 35.36 Average: 11 1.96 0.00 43.68 54.37 0.00 0.00 0.00 0.00 0.00 0.00 [0] https://github.com/isilence/liburing/tree/zcrx/rx-buf-len [1] commands: $> taskset -c 9 ./zcrx 6 -i eth2 -q 9 -A 1 -B 4096 -S 33554432 $> ./send-zerocopy tcp -6 -D 2001:db8::1 -t 60 -C 0 -l 1 -b 1 -n 1 -z 1 -d -s 256000 [2] commands: $> taskset -c 9 ./zcrx 6 -i eth2 -q 9 -A 1 -B 131072 -S 33554432 $> ./send-zerocopy tcp -6 -D 2001:db8::1 -t 60 -C 0 -l 1 -b 1 -n 1 -z 1 -d -s 256000 [3] commands: $> taskset -c 11 ./zcrx 6 -i eth2 -q 9 -A 1 -B 4096 -S 33554432 $> ./send-zerocopy tcp -6 -D 2001:db8::1 -t 60 -C 0 -l 1 -b 1 -n 1 -z 1 -d -s 256000 [4] commands: $> taskset -c 11 ./zcrx 6 -i eth2 -q 9 -A 1 -B 131072 -S 33554432 $> ./send-zerocopy tcp -6 -D 2001:db8::1 -t 60 -C 0 -l 1 -b 1 -n 1 -z 1 -d -s 256000 Signed-off-by: Dragos Tatulea Reviewed-by: Cosmin Ratiu Signed-off-by: Tariq Toukan --- .../net/ethernet/mellanox/mlx5/core/en_main.c | 36 ++++++++++++++++++- 1 file changed, 35 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c index 59e38e7e067e..67dc38981101 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c @@ -5586,12 +5586,40 @@ static int mlx5e_queue_validate_qcfg(struct net_device *dev, struct netdev_queue_config *qcfg, struct netlink_ext_ack *extack) { - if (qcfg->rx_page_size != PAGE_SIZE) + struct mlx5e_priv *priv = netdev_priv(dev); + struct mlx5_core_dev *mdev = priv->mdev; + u32 max; + + if (!is_power_of_2(qcfg->rx_page_size)) { + netdev_err(priv->netdev, "rx_page_size not power of 2: %u", + qcfg->rx_page_size); return -EINVAL; + } + + max = mlx5e_mpwrq_max_page_size(mdev); + if (qcfg->rx_page_size < PAGE_SIZE || qcfg->rx_page_size > max) { + netdev_err(priv->netdev, + "Selected rx_page_size %u not in supported range [%lu, %u]\n", + qcfg->rx_page_size, PAGE_SIZE, max); + return -ERANGE; + } return 0; } +static bool mlx5e_queue_validate_page_size(struct net_device *dev, + struct netdev_queue_config *qcfg, + int queue_index) +{ + if (qcfg->rx_page_size == PAGE_SIZE) + return true; + + if (!netif_rxq_has_unreadable_mp(dev, queue_index)) + return false; + + return true; +} + static int mlx5e_queue_mem_alloc(struct net_device *dev, struct netdev_queue_config *qcfg, void *newq, int queue_index) @@ -5623,6 +5651,12 @@ static int mlx5e_queue_mem_alloc(struct net_device *dev, goto unlock; } + if (!mlx5e_queue_validate_page_size(dev, qcfg, queue_index)) { + netdev_err(priv->netdev, "High order pages are supported only in Zero-Copy mode\n"); + err = -EINVAL; + goto unlock; + } + err = mlx5e_open_channel(priv, queue_index, ¶ms, qcfg, NULL, &new->c); unlock: -- 2.44.0