From 0c3b9d1b37df16ae6046a5a01f769bf3d21b838c Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 27 Sep 2018 09:32:01 -0700 Subject: [PATCH] ibmvnic: 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. ibmvnic uses NAPI for TX completions, so we better let core networking stack call the napi->poll() to avoid the capture. ibmvnic_netpoll_controller() was completely wrong anyway, as it was scheduling NAPI to service RX queues (instead of TX), so I doubt netpoll ever worked on this driver. Signed-off-by: Eric Dumazet Cc: Thomas Falcon Cc: John Allen Signed-off-by: David S. Miller --- drivers/net/ethernet/ibm/ibmvnic.c | 16 ---------------- 1 file changed, 16 deletions(-) diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c index 4f0daf67b18d..699ef942b615 100644 --- a/drivers/net/ethernet/ibm/ibmvnic.c +++ b/drivers/net/ethernet/ibm/ibmvnic.c @@ -2207,19 +2207,6 @@ static int ibmvnic_poll(struct napi_struct *napi, int budget) return frames_processed; } -#ifdef CONFIG_NET_POLL_CONTROLLER -static void ibmvnic_netpoll_controller(struct net_device *dev) -{ - struct ibmvnic_adapter *adapter = netdev_priv(dev); - int i; - - replenish_pools(netdev_priv(dev)); - for (i = 0; i < adapter->req_rx_queues; i++) - ibmvnic_interrupt_rx(adapter->rx_scrq[i]->irq, - adapter->rx_scrq[i]); -} -#endif - static int wait_for_reset(struct ibmvnic_adapter *adapter) { int rc, ret; @@ -2292,9 +2279,6 @@ static const struct net_device_ops ibmvnic_netdev_ops = { .ndo_set_mac_address = ibmvnic_set_mac, .ndo_validate_addr = eth_validate_addr, .ndo_tx_timeout = ibmvnic_tx_timeout, -#ifdef CONFIG_NET_POLL_CONTROLLER - .ndo_poll_controller = ibmvnic_netpoll_controller, -#endif .ndo_change_mtu = ibmvnic_change_mtu, .ndo_features_check = ibmvnic_features_check, }; -- GitLab