From 2a7f8c3b1d3feedee3aa319ac220cbde3725b5d5 Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Sat, 29 Sep 2018 14:52:56 +0200 Subject: [PATCH] hv_netvsc: remove ndo_poll_controller Similar to other patches from ERic. 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. In netvsc driver it uses NAPI for TX completions. The default poll_napi will do this for us now and avoid the capture. Signed-off-by: Stephen Hemminger Cc: Haiyang Zhang Cc: Eric Dumazet Reviewed-by: Haiyang Zhang Signed-off-by: David S. Miller --- drivers/net/hyperv/netvsc_drv.c | 23 ----------------------- 1 file changed, 23 deletions(-) diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c index 005cbaa2fa3b..9bcaf204a7d4 100644 --- a/drivers/net/hyperv/netvsc_drv.c +++ b/drivers/net/hyperv/netvsc_drv.c @@ -1565,26 +1565,6 @@ netvsc_set_rxnfc(struct net_device *ndev, struct ethtool_rxnfc *info) return -EOPNOTSUPP; } -#ifdef CONFIG_NET_POLL_CONTROLLER -static void netvsc_poll_controller(struct net_device *dev) -{ - struct net_device_context *ndc = netdev_priv(dev); - struct netvsc_device *ndev; - int i; - - rcu_read_lock(); - ndev = rcu_dereference(ndc->nvdev); - if (ndev) { - for (i = 0; i < ndev->num_chn; i++) { - struct netvsc_channel *nvchan = &ndev->chan_table[i]; - - napi_schedule(&nvchan->napi); - } - } - rcu_read_unlock(); -} -#endif - static u32 netvsc_get_rxfh_key_size(struct net_device *dev) { return NETVSC_HASH_KEYLEN; @@ -1812,9 +1792,6 @@ static const struct net_device_ops device_ops = { .ndo_set_mac_address = netvsc_set_mac_addr, .ndo_select_queue = netvsc_select_queue, .ndo_get_stats64 = netvsc_get_stats64, -#ifdef CONFIG_NET_POLL_CONTROLLER - .ndo_poll_controller = netvsc_poll_controller, -#endif }; /*