From 4bd2c03be707253f1157bd759fdd6971e4f70403 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 27 Sep 2018 09:31:54 -0700 Subject: [PATCH] net: hns: 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. hns 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: Yisen Zhuang Cc: Salil Mehta Signed-off-by: David S. Miller --- drivers/net/ethernet/hisilicon/hns/hns_enet.c | 18 ------------------ 1 file changed, 18 deletions(-) diff --git a/drivers/net/ethernet/hisilicon/hns/hns_enet.c b/drivers/net/ethernet/hisilicon/hns/hns_enet.c index 5ce23d4b717e..28e907831b0e 100644 --- a/drivers/net/ethernet/hisilicon/hns/hns_enet.c +++ b/drivers/net/ethernet/hisilicon/hns/hns_enet.c @@ -1503,21 +1503,6 @@ static int hns_nic_do_ioctl(struct net_device *netdev, struct ifreq *ifr, return phy_mii_ioctl(phy_dev, ifr, cmd); } -/* use only for netconsole to poll with the device without interrupt */ -#ifdef CONFIG_NET_POLL_CONTROLLER -static void hns_nic_poll_controller(struct net_device *ndev) -{ - struct hns_nic_priv *priv = netdev_priv(ndev); - unsigned long flags; - int i; - - local_irq_save(flags); - for (i = 0; i < priv->ae_handle->q_num * 2; i++) - napi_schedule(&priv->ring_data[i].napi); - local_irq_restore(flags); -} -#endif - static netdev_tx_t hns_nic_net_xmit(struct sk_buff *skb, struct net_device *ndev) { @@ -1970,9 +1955,6 @@ static const struct net_device_ops hns_nic_netdev_ops = { .ndo_set_features = hns_nic_set_features, .ndo_fix_features = hns_nic_fix_features, .ndo_get_stats64 = hns_nic_get_stats64, -#ifdef CONFIG_NET_POLL_CONTROLLER - .ndo_poll_controller = hns_nic_poll_controller, -#endif .ndo_set_rx_mode = hns_nic_set_rx_mode, .ndo_select_queue = hns_nic_select_queue, }; -- GitLab