From 260dd2c3e2aeefbe78065f0737dceae1ceb1196a Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 27 Sep 2018 09:31:55 -0700 Subject: [PATCH] virtio_net: remove ndo_poll_controller 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. virto_net 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 Cc: "Michael S. Tsirkin" Cc: Jason Wang Signed-off-by: David S. Miller --- drivers/net/virtio_net.c | 14 -------------- 1 file changed, 14 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 7659209..dab504e 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -1699,17 +1699,6 @@ static void virtnet_stats(struct net_device *dev, tot->rx_frame_errors = dev->stats.rx_frame_errors; } -#ifdef CONFIG_NET_POLL_CONTROLLER -static void virtnet_netpoll(struct net_device *dev) -{ - struct virtnet_info *vi = netdev_priv(dev); - int i; - - for (i = 0; i < vi->curr_queue_pairs; i++) - napi_schedule(&vi->rq[i].napi); -} -#endif - static void virtnet_ack_link_announce(struct virtnet_info *vi) { rtnl_lock(); @@ -2447,9 +2436,6 @@ static const struct net_device_ops virtnet_netdev = { .ndo_get_stats64 = virtnet_stats, .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid, .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid, -#ifdef CONFIG_NET_POLL_CONTROLLER - .ndo_poll_controller = virtnet_netpoll, -#endif .ndo_bpf = virtnet_xdp, .ndo_xdp_xmit = virtnet_xdp_xmit, .ndo_features_check = passthru_features_check, -- 2.7.4