From: Eric Dumazet Date: Thu, 27 Sep 2018 16:31:58 +0000 (-0700) Subject: net: ena: remove ndo_poll_controller X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=21627982e4fff76a053f4d08d7fb56e532e08d52;p=openwrt%2Fstaging%2Fblogic.git net: ena: 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. ena 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: Netanel Belgazal Cc: Saeed Bishara Cc: Zorik Machulsky Signed-off-by: David S. Miller --- diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c index 29b5774dd32d..25621a218f20 100644 --- a/drivers/net/ethernet/amazon/ena/ena_netdev.c +++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c @@ -2185,25 +2185,6 @@ error_drop_packet: return NETDEV_TX_OK; } -#ifdef CONFIG_NET_POLL_CONTROLLER -static void ena_netpoll(struct net_device *netdev) -{ - struct ena_adapter *adapter = netdev_priv(netdev); - int i; - - /* Dont schedule NAPI if the driver is in the middle of reset - * or netdev is down. - */ - - if (!test_bit(ENA_FLAG_DEV_UP, &adapter->flags) || - test_bit(ENA_FLAG_TRIGGER_RESET, &adapter->flags)) - return; - - for (i = 0; i < adapter->num_queues; i++) - napi_schedule(&adapter->ena_napi[i].napi); -} -#endif /* CONFIG_NET_POLL_CONTROLLER */ - static u16 ena_select_queue(struct net_device *dev, struct sk_buff *skb, struct net_device *sb_dev, select_queue_fallback_t fallback) @@ -2369,9 +2350,6 @@ static const struct net_device_ops ena_netdev_ops = { .ndo_change_mtu = ena_change_mtu, .ndo_set_mac_address = NULL, .ndo_validate_addr = eth_validate_addr, -#ifdef CONFIG_NET_POLL_CONTROLLER - .ndo_poll_controller = ena_netpoll, -#endif /* CONFIG_NET_POLL_CONTROLLER */ }; static int ena_device_validate_params(struct ena_adapter *adapter,