From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: [PATCH net 07/11] qlogic: netxen: remove ndo_poll_controller Date: Thu, 27 Sep 2018 09:31:57 -0700 Message-ID: <20180927163201.56609-8-edumazet@google.com> References: <20180927163201.56609-1-edumazet@google.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Cc: netdev , Eric Dumazet , Michael Chan , Aviad Krawczyk , Song Liu , Douglas Miller , Yisen Zhuang , "Michael S . Tsirkin" , Jason Wang , Harish Patil , Manish Chopra , Netanel Belgazal , Solarflare linux maintainers , Thomas Falcon , Rahul Verma To: "David S . Miller" Return-path: Received: from mail-pf1-f193.google.com ([209.85.210.193]:42548 "EHLO mail-pf1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728139AbeI0Wvs (ORCPT ); Thu, 27 Sep 2018 18:51:48 -0400 Received: by mail-pf1-f193.google.com with SMTP id l9-v6so2270245pff.9 for ; Thu, 27 Sep 2018 09:32:44 -0700 (PDT) In-Reply-To: <20180927163201.56609-1-edumazet@google.com> Sender: netdev-owner@vger.kernel.org List-ID: 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 --- .../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 69aa7fc392c5e4ad1cbcd9025f56bffdf3aa92c7..59c70be22a84c11262388529cf0ddf09887cea96 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) { -- 2.19.0.605.g01d371f741-goog