From: Eric Dumazet <edumazet@google.com>
Date: Fri, 21 Sep 2018 15:27:51 -0700
Subject: nfp: remove ndo_poll_controller
Patch-mainline: v4.19-rc6
Git-commit: 0825ce70318e9c576acbdd5ceb4a8d563263cf8f
References: bsc#1109837
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.
nfp 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: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Tested-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/net/ethernet/netronome/nfp/nfp_net_common.c | 18 ------------------
1 file changed, 18 deletions(-)
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
@@ -3146,21 +3146,6 @@ nfp_net_vlan_rx_kill_vid(struct net_devi
return nfp_net_reconfig_mbox(nn, NFP_NET_CFG_MBOX_CMD_CTAG_FILTER_KILL);
}
-#ifdef CONFIG_NET_POLL_CONTROLLER
-static void nfp_net_netpoll(struct net_device *netdev)
-{
- struct nfp_net *nn = netdev_priv(netdev);
- int i;
-
- /* nfp_net's NAPIs are statically allocated so even if there is a race
- * with reconfig path this will simply try to schedule some disabled
- * NAPI instances.
- */
- for (i = 0; i < nn->dp.num_stack_tx_rings; i++)
- napi_schedule_irqoff(&nn->r_vecs[i].napi);
-}
-#endif
-
static void nfp_net_stat64(struct net_device *netdev,
struct rtnl_link_stats64 *stats)
{
@@ -3519,9 +3504,6 @@ const struct net_device_ops nfp_net_netd
.ndo_get_stats64 = nfp_net_stat64,
.ndo_vlan_rx_add_vid = nfp_net_vlan_rx_add_vid,
.ndo_vlan_rx_kill_vid = nfp_net_vlan_rx_kill_vid,
-#ifdef CONFIG_NET_POLL_CONTROLLER
- .ndo_poll_controller = nfp_net_netpoll,
-#endif
.ndo_set_vf_mac = nfp_app_set_vf_mac,
.ndo_set_vf_vlan = nfp_app_set_vf_vlan,
.ndo_set_vf_spoofchk = nfp_app_set_vf_spoofchk,