From c24498c6827b71f80fecc9fb1b70a792053d41a9 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 27 Sep 2018 09:31:51 -0700 Subject: [PATCH 01/11] netpoll: do not test NAPI_STATE_SCHED in poll_one_napi() Since we do no longer require NAPI drivers to provide an ndo_poll_controller(), napi_schedule() has not been done before poll_one_napi() invocation. So testing NAPI_STATE_SCHED is likely to cause early returns. While we are at it, remove outdated comment. Note to future bisections : This change might surface prior bugs in drivers. See commit 73f21c653f93 ("bnxt_en: Fix TX timeout during netpoll.") for one occurrence. Fixes: ac3d9dd034e5 ("netpoll: make ndo_poll_controller() optional") Signed-off-by: Eric Dumazet Tested-by: Song Liu Cc: Michael Chan Signed-off-by: David S. Miller --- net/core/netpoll.c | 20 +------------------- 1 file changed, 1 insertion(+), 19 deletions(-) diff --git a/net/core/netpoll.c b/net/core/netpoll.c index 3219a2932463..3ae899805f8b 100644 --- a/net/core/netpoll.c +++ b/net/core/netpoll.c @@ -135,27 +135,9 @@ static void queue_process(struct work_struct *work) } } -/* - * Check whether delayed processing was scheduled for our NIC. If so, - * we attempt to grab the poll lock and use ->poll() to pump the card. - * If this fails, either we've recursed in ->poll() or it's already - * running on another CPU. - * - * Note: we don't mask interrupts with this lock because we're using - * trylock here and interrupts are already disabled in the softirq - * case. Further, we test the poll_owner to avoid recursion on UP - * systems where the lock doesn't exist. - */ static void poll_one_napi(struct napi_struct *napi) { - int work = 0; - - /* net_rx_action's ->poll() invocations and our's are - * synchronized by this test which is only made while - * holding the napi->poll_lock. - */ - if (!test_bit(NAPI_STATE_SCHED, &napi->state)) - return; + int work; /* If we set this bit but see that it has already been set, * that indicates that napi has been disabled and we need From e71fb423e0dea3c9f98f0101e965426edfe849cd Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 27 Sep 2018 09:31:52 -0700 Subject: [PATCH 02/11] hinic: 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. hinic uses NAPI for TX completions, so we better let core networking stack call the napi->poll() to avoid the capture. Note that hinic_netpoll() was incorrectly scheduling NAPI on both RX and TX queues. Signed-off-by: Eric Dumazet Cc: Aviad Krawczyk Signed-off-by: David S. Miller --- .../net/ethernet/huawei/hinic/hinic_main.c | 20 ------------------- 1 file changed, 20 deletions(-) diff --git a/drivers/net/ethernet/huawei/hinic/hinic_main.c b/drivers/net/ethernet/huawei/hinic/hinic_main.c index 09e9da10b786..4a8f82938ed5 100644 --- a/drivers/net/ethernet/huawei/hinic/hinic_main.c +++ b/drivers/net/ethernet/huawei/hinic/hinic_main.c @@ -789,23 +789,6 @@ static void hinic_get_stats64(struct net_device *netdev, stats->tx_errors = nic_tx_stats->tx_dropped; } -#ifdef CONFIG_NET_POLL_CONTROLLER -static void hinic_netpoll(struct net_device *netdev) -{ - struct hinic_dev *nic_dev = netdev_priv(netdev); - int i, num_qps; - - num_qps = hinic_hwdev_num_qps(nic_dev->hwdev); - for (i = 0; i < num_qps; i++) { - struct hinic_txq *txq = &nic_dev->txqs[i]; - struct hinic_rxq *rxq = &nic_dev->rxqs[i]; - - napi_schedule(&txq->napi); - napi_schedule(&rxq->napi); - } -} -#endif - static const struct net_device_ops hinic_netdev_ops = { .ndo_open = hinic_open, .ndo_stop = hinic_close, @@ -818,9 +801,6 @@ static const struct net_device_ops hinic_netdev_ops = { .ndo_start_xmit = hinic_xmit_frame, .ndo_tx_timeout = hinic_tx_timeout, .ndo_get_stats64 = hinic_get_stats64, -#ifdef CONFIG_NET_POLL_CONTROLLER - .ndo_poll_controller = hinic_netpoll, -#endif }; static void netdev_features_init(struct net_device *netdev) From 226a2dd62c5d789088fcf7804fbe5613887870a5 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 27 Sep 2018 09:31:53 -0700 Subject: [PATCH 03/11] ehea: 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. ehea 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: Douglas Miller Signed-off-by: David S. Miller --- drivers/net/ethernet/ibm/ehea/ehea_main.c | 14 -------------- 1 file changed, 14 deletions(-) diff --git a/drivers/net/ethernet/ibm/ehea/ehea_main.c b/drivers/net/ethernet/ibm/ehea/ehea_main.c index ba580bfae512..03f64f40b2a3 100644 --- a/drivers/net/ethernet/ibm/ehea/ehea_main.c +++ b/drivers/net/ethernet/ibm/ehea/ehea_main.c @@ -921,17 +921,6 @@ static int ehea_poll(struct napi_struct *napi, int budget) return rx; } -#ifdef CONFIG_NET_POLL_CONTROLLER -static void ehea_netpoll(struct net_device *dev) -{ - struct ehea_port *port = netdev_priv(dev); - int i; - - for (i = 0; i < port->num_def_qps; i++) - napi_schedule(&port->port_res[i].napi); -} -#endif - static irqreturn_t ehea_recv_irq_handler(int irq, void *param) { struct ehea_port_res *pr = param; @@ -2953,9 +2942,6 @@ static const struct net_device_ops ehea_netdev_ops = { .ndo_open = ehea_open, .ndo_stop = ehea_stop, .ndo_start_xmit = ehea_start_xmit, -#ifdef CONFIG_NET_POLL_CONTROLLER - .ndo_poll_controller = ehea_netpoll, -#endif .ndo_get_stats64 = ehea_get_stats64, .ndo_set_mac_address = ehea_set_mac_addr, .ndo_validate_addr = eth_validate_addr, From 4bd2c03be707253f1157bd759fdd6971e4f70403 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 27 Sep 2018 09:31:54 -0700 Subject: [PATCH 04/11] 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, }; From 260dd2c3e2aeefbe78065f0737dceae1ceb1196a Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 27 Sep 2018 09:31:55 -0700 Subject: [PATCH 05/11] 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 765920905226..dab504ec5e50 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, From 81b059b2187d77b957bf85318dbd4f36d60555e3 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 27 Sep 2018 09:31:56 -0700 Subject: [PATCH 06/11] qlcnic: 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. qlcnic 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: Harish Patil Cc: Manish Chopra Signed-off-by: David S. Miller --- .../net/ethernet/qlogic/qlcnic/qlcnic_main.c | 45 ------------------- 1 file changed, 45 deletions(-) diff --git a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c index 2d38d1ac2aae..dbd48012224f 100644 --- a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c +++ b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c @@ -59,9 +59,6 @@ static int qlcnic_close(struct net_device *netdev); static void qlcnic_tx_timeout(struct net_device *netdev); static void qlcnic_attach_work(struct work_struct *work); static void qlcnic_fwinit_work(struct work_struct *work); -#ifdef CONFIG_NET_POLL_CONTROLLER -static void qlcnic_poll_controller(struct net_device *netdev); -#endif static void qlcnic_idc_debug_info(struct qlcnic_adapter *adapter, u8 encoding); static int qlcnic_can_start_firmware(struct qlcnic_adapter *adapter); @@ -545,9 +542,6 @@ static const struct net_device_ops qlcnic_netdev_ops = { .ndo_udp_tunnel_add = qlcnic_add_vxlan_port, .ndo_udp_tunnel_del = qlcnic_del_vxlan_port, .ndo_features_check = qlcnic_features_check, -#ifdef CONFIG_NET_POLL_CONTROLLER - .ndo_poll_controller = qlcnic_poll_controller, -#endif #ifdef CONFIG_QLCNIC_SRIOV .ndo_set_vf_mac = qlcnic_sriov_set_vf_mac, .ndo_set_vf_rate = qlcnic_sriov_set_vf_tx_rate, @@ -3200,45 +3194,6 @@ static irqreturn_t qlcnic_msix_tx_intr(int irq, void *data) return IRQ_HANDLED; } -#ifdef CONFIG_NET_POLL_CONTROLLER -static void qlcnic_poll_controller(struct net_device *netdev) -{ - struct qlcnic_adapter *adapter = netdev_priv(netdev); - struct qlcnic_host_sds_ring *sds_ring; - struct qlcnic_recv_context *recv_ctx; - struct qlcnic_host_tx_ring *tx_ring; - int ring; - - if (!test_bit(__QLCNIC_DEV_UP, &adapter->state)) - return; - - recv_ctx = adapter->recv_ctx; - - for (ring = 0; ring < adapter->drv_sds_rings; ring++) { - sds_ring = &recv_ctx->sds_rings[ring]; - qlcnic_disable_sds_intr(adapter, sds_ring); - napi_schedule(&sds_ring->napi); - } - - if (adapter->flags & QLCNIC_MSIX_ENABLED) { - /* Only Multi-Tx queue capable devices need to - * schedule NAPI for TX rings - */ - if ((qlcnic_83xx_check(adapter) && - (adapter->flags & QLCNIC_TX_INTR_SHARED)) || - (qlcnic_82xx_check(adapter) && - !qlcnic_check_multi_tx(adapter))) - return; - - for (ring = 0; ring < adapter->drv_tx_rings; ring++) { - tx_ring = &adapter->tx_ring[ring]; - qlcnic_disable_tx_intr(adapter, tx_ring); - napi_schedule(&tx_ring->napi); - } - } -} -#endif - static void qlcnic_idc_debug_info(struct qlcnic_adapter *adapter, u8 encoding) { From 3548fcf7d877c682c9a5a413c51929739192156d Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 27 Sep 2018 09:31:57 -0700 Subject: [PATCH 07/11] qlogic: netxen: 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. netxen 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: Manish Chopra Cc: Rahul Verma Signed-off-by: David S. Miller --- .../ethernet/qlogic/netxen/netxen_nic_main.c | 23 ------------------- 1 file changed, 23 deletions(-) diff --git a/drivers/net/ethernet/qlogic/netxen/netxen_nic_main.c b/drivers/net/ethernet/qlogic/netxen/netxen_nic_main.c index 69aa7fc392c5..59c70be22a84 100644 --- a/drivers/net/ethernet/qlogic/netxen/netxen_nic_main.c +++ b/drivers/net/ethernet/qlogic/netxen/netxen_nic_main.c @@ -72,9 +72,6 @@ static void netxen_schedule_work(struct netxen_adapter *adapter, work_func_t func, int delay); static void netxen_cancel_fw_work(struct netxen_adapter *adapter); static int netxen_nic_poll(struct napi_struct *napi, int budget); -#ifdef CONFIG_NET_POLL_CONTROLLER -static void netxen_nic_poll_controller(struct net_device *netdev); -#endif static void netxen_create_sysfs_entries(struct netxen_adapter *adapter); static void netxen_remove_sysfs_entries(struct netxen_adapter *adapter); @@ -581,9 +578,6 @@ static const struct net_device_ops netxen_netdev_ops = { .ndo_tx_timeout = netxen_tx_timeout, .ndo_fix_features = netxen_fix_features, .ndo_set_features = netxen_set_features, -#ifdef CONFIG_NET_POLL_CONTROLLER - .ndo_poll_controller = netxen_nic_poll_controller, -#endif }; static inline bool netxen_function_zero(struct pci_dev *pdev) @@ -2402,23 +2396,6 @@ static int netxen_nic_poll(struct napi_struct *napi, int budget) return work_done; } -#ifdef CONFIG_NET_POLL_CONTROLLER -static void netxen_nic_poll_controller(struct net_device *netdev) -{ - int ring; - struct nx_host_sds_ring *sds_ring; - struct netxen_adapter *adapter = netdev_priv(netdev); - struct netxen_recv_context *recv_ctx = &adapter->recv_ctx; - - disable_irq(adapter->irq); - for (ring = 0; ring < adapter->max_sds_rings; ring++) { - sds_ring = &recv_ctx->sds_rings[ring]; - netxen_intr(adapter->irq, sds_ring); - } - enable_irq(adapter->irq); -} -#endif - static int nx_incr_dev_ref_cnt(struct netxen_adapter *adapter) { From 21627982e4fff76a053f4d08d7fb56e532e08d52 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 27 Sep 2018 09:31:58 -0700 Subject: [PATCH 08/11] 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 --- drivers/net/ethernet/amazon/ena/ena_netdev.c | 22 -------------------- 1 file changed, 22 deletions(-) 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 @@ static netdev_tx_t ena_start_xmit(struct sk_buff *skb, struct net_device *dev) 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, From 9447a10ff607debe5e30cc438fb56925a559b9d9 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 27 Sep 2018 09:31:59 -0700 Subject: [PATCH 09/11] sfc: 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. sfc 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: Edward Cree Cc: Bert Kenward Cc: Solarflare linux maintainers Acked-By: Bert Kenward Signed-off-by: David S. Miller --- drivers/net/ethernet/sfc/efx.c | 26 -------------------------- 1 file changed, 26 deletions(-) diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c index 330233286e78..3d0dd39c289e 100644 --- a/drivers/net/ethernet/sfc/efx.c +++ b/drivers/net/ethernet/sfc/efx.c @@ -2206,29 +2206,6 @@ static void efx_fini_napi(struct efx_nic *efx) efx_fini_napi_channel(channel); } -/************************************************************************** - * - * Kernel netpoll interface - * - *************************************************************************/ - -#ifdef CONFIG_NET_POLL_CONTROLLER - -/* Although in the common case interrupts will be disabled, this is not - * guaranteed. However, all our work happens inside the NAPI callback, - * so no locking is required. - */ -static void efx_netpoll(struct net_device *net_dev) -{ - struct efx_nic *efx = netdev_priv(net_dev); - struct efx_channel *channel; - - efx_for_each_channel(channel, efx) - efx_schedule_channel(channel); -} - -#endif - /************************************************************************** * * Kernel net device interface @@ -2509,9 +2486,6 @@ static const struct net_device_ops efx_netdev_ops = { #endif .ndo_get_phys_port_id = efx_get_phys_port_id, .ndo_get_phys_port_name = efx_get_phys_port_name, -#ifdef CONFIG_NET_POLL_CONTROLLER - .ndo_poll_controller = efx_netpoll, -#endif .ndo_setup_tc = efx_setup_tc, #ifdef CONFIG_RFS_ACCEL .ndo_rx_flow_steer = efx_filter_rfs, From a4f570be654de779eaf626a79c4e0aa5a790505f Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 27 Sep 2018 09:32:00 -0700 Subject: [PATCH 10/11] sfc-falcon: 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. sfc-falcon 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: Solarflare linux maintainers Cc: Edward Cree Cc: Bert Kenward Acked-By: Bert Kenward Signed-off-by: David S. Miller --- drivers/net/ethernet/sfc/falcon/efx.c | 26 -------------------------- 1 file changed, 26 deletions(-) diff --git a/drivers/net/ethernet/sfc/falcon/efx.c b/drivers/net/ethernet/sfc/falcon/efx.c index dd5530a4f8c8..03e2455c502e 100644 --- a/drivers/net/ethernet/sfc/falcon/efx.c +++ b/drivers/net/ethernet/sfc/falcon/efx.c @@ -2052,29 +2052,6 @@ static void ef4_fini_napi(struct ef4_nic *efx) ef4_fini_napi_channel(channel); } -/************************************************************************** - * - * Kernel netpoll interface - * - *************************************************************************/ - -#ifdef CONFIG_NET_POLL_CONTROLLER - -/* Although in the common case interrupts will be disabled, this is not - * guaranteed. However, all our work happens inside the NAPI callback, - * so no locking is required. - */ -static void ef4_netpoll(struct net_device *net_dev) -{ - struct ef4_nic *efx = netdev_priv(net_dev); - struct ef4_channel *channel; - - ef4_for_each_channel(channel, efx) - ef4_schedule_channel(channel); -} - -#endif - /************************************************************************** * * Kernel net device interface @@ -2250,9 +2227,6 @@ static const struct net_device_ops ef4_netdev_ops = { .ndo_set_mac_address = ef4_set_mac_address, .ndo_set_rx_mode = ef4_set_rx_mode, .ndo_set_features = ef4_set_features, -#ifdef CONFIG_NET_POLL_CONTROLLER - .ndo_poll_controller = ef4_netpoll, -#endif .ndo_setup_tc = ef4_setup_tc, #ifdef CONFIG_RFS_ACCEL .ndo_rx_flow_steer = ef4_filter_rfs, From 0c3b9d1b37df16ae6046a5a01f769bf3d21b838c Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 27 Sep 2018 09:32:01 -0700 Subject: [PATCH 11/11] 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, };