From bb2146bc883e86b835e30644757a6d4a649a7ce8 Mon Sep 17 00:00:00 2001 From: Ido Shamay Date: Fri, 21 Feb 2014 12:39:18 +0200 Subject: [PATCH] net/mlx4: Fix limiting number of IRQ's instead of RSS queues This fix a performance bug introduced by commit 90b1ebe "mlx4: set maximal number of default RSS queues", which limits the numbers of IRQs opened by core module. The limit should be on the number of queues in the indirection table - rx_rings, and not on the number of IRQ's. Also, limiting on mlx4_core initialization instead of in mlx4_en, prevented using "ethtool -L" to utilize all the CPU's, when performance mode is prefered, since limiting this number to 8 reduces overall packet rate by 15%-50% in multiple TCP streams applications. For example, after running ethtool -L rx 16 Packet rate Before the fix 897799 After the fix 1142070 Results were obtained using netperf: S=200 ; ( for i in $(seq 1 $S) ; do ( \ netperf -H 11.7.13.55 -t TCP_RR -l 30 &) ; \ wait ; done | grep "1 1" | awk '{SUM+=$6} END {print SUM}' ) CC: Yuval Mintz Signed-off-by: Ido Shamay Signed-off-by: Amir Vadai Signed-off-by: David S. Miller --- drivers/net/ethernet/mellanox/mlx4/en_rx.c | 5 ++++- drivers/net/ethernet/mellanox/mlx4/main.c | 3 +-- 2 files changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c index 85434d73c9bc..8afb72ec957d 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c @@ -322,6 +322,7 @@ void mlx4_en_set_num_rx_rings(struct mlx4_en_dev *mdev) { int i; int num_of_eqs; + int num_rx_rings; struct mlx4_dev *dev = mdev->dev; mlx4_foreach_port(i, dev, MLX4_PORT_TYPE_ETH) { @@ -335,8 +336,10 @@ void mlx4_en_set_num_rx_rings(struct mlx4_en_dev *mdev) dev->caps.comp_pool/ dev->caps.num_ports) - 1; + num_rx_rings = min_t(int, num_of_eqs, + netif_get_num_default_rss_queues()); mdev->profile.prof[i].rx_ring_num = - rounddown_pow_of_two(num_of_eqs); + rounddown_pow_of_two(num_rx_rings); } } diff --git a/drivers/net/ethernet/mellanox/mlx4/main.c b/drivers/net/ethernet/mellanox/mlx4/main.c index 218b759c506e..979ea4364efb 100644 --- a/drivers/net/ethernet/mellanox/mlx4/main.c +++ b/drivers/net/ethernet/mellanox/mlx4/main.c @@ -41,7 +41,6 @@ #include #include #include -#include #include #include @@ -1974,7 +1973,7 @@ static void mlx4_enable_msi_x(struct mlx4_dev *dev) struct mlx4_priv *priv = mlx4_priv(dev); struct msix_entry *entries; int nreq = min_t(int, dev->caps.num_ports * - min_t(int, netif_get_num_default_rss_queues() + 1, + min_t(int, num_online_cpus() + 1, MAX_MSIX_P_PORT) + MSIX_LEGACY_SZ, MAX_MSIX); int i; -- 2.20.1