From: Eric Dumazet <edumazet@google.com>
Date: Fri, 21 Sep 2018 15:27:47 -0700
Subject: mlx4: remove ndo_poll_controller
Patch-mainline: v4.19-rc6
Git-commit: a24b66c249f71dde11da5ba3b4c397a42ece3fc9
References: bsc#1103989 FATE#326004
As diagnosed by Song Liu, ndo_poll_controller() can
be very dangerous on loaded hosts, since the cpu
calling ndo_poll_controller() might steal all NAPI
contexts (for all RX/TX queues of the NIC). This capture
can last for unlimited amount of time, since one
cpu is generally not able to drain all the queues under load.
mlx4 uses NAPI for TX completions, so we better let core
networking stack call the napi->poll() to avoid the capture.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/net/ethernet/mellanox/mlx4/en_netdev.c | 20 --------------------
1 file changed, 20 deletions(-)
--- a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
@@ -1286,20 +1286,6 @@ out:
mutex_unlock(&mdev->state_lock);
}
-#ifdef CONFIG_NET_POLL_CONTROLLER
-static void mlx4_en_netpoll(struct net_device *dev)
-{
- struct mlx4_en_priv *priv = netdev_priv(dev);
- struct mlx4_en_cq *cq;
- int i;
-
- for (i = 0; i < priv->tx_ring_num[TX]; i++) {
- cq = priv->tx_cq[TX][i];
- napi_schedule(&cq->napi);
- }
-}
-#endif
-
static int mlx4_en_set_rss_steer_rules(struct mlx4_en_priv *priv)
{
u64 reg_id;
@@ -2944,9 +2930,6 @@ static const struct net_device_ops mlx4_
.ndo_tx_timeout = mlx4_en_tx_timeout,
.ndo_vlan_rx_add_vid = mlx4_en_vlan_rx_add_vid,
.ndo_vlan_rx_kill_vid = mlx4_en_vlan_rx_kill_vid,
-#ifdef CONFIG_NET_POLL_CONTROLLER
- .ndo_poll_controller = mlx4_en_netpoll,
-#endif
.ndo_set_features = mlx4_en_set_features,
.ndo_fix_features = mlx4_en_fix_features,
.ndo_setup_tc = __mlx4_en_setup_tc,
@@ -2981,9 +2964,6 @@ static const struct net_device_ops mlx4_
.ndo_set_vf_link_state = mlx4_en_set_vf_link_state,
.ndo_get_vf_stats = mlx4_en_get_vf_stats,
.ndo_get_vf_config = mlx4_en_get_vf_config,
-#ifdef CONFIG_NET_POLL_CONTROLLER
- .ndo_poll_controller = mlx4_en_netpoll,
-#endif
.ndo_set_features = mlx4_en_set_features,
.ndo_fix_features = mlx4_en_fix_features,
.ndo_setup_tc = __mlx4_en_setup_tc,