From: Eric Dumazet <edumazet@google.com>
Date: Thu, 27 Sep 2018 09:31:58 -0700
Subject: net: ena: remove ndo_poll_controller
Patch-mainline: v4.19-rc7
Git-commit: 21627982e4fff76a053f4d08d7fb56e532e08d52
References: bsc#1111696 bsc#1117561
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 <edumazet@google.com>
Cc: Netanel Belgazal <netanel@amazon.com>
Cc: Saeed Bishara <saeedb@amazon.com>
Cc: Zorik Machulsky <zorik@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/net/ethernet/amazon/ena/ena_netdev.c | 22 ----------------------
1 file changed, 22 deletions(-)
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.c
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c
@@ -2185,25 +2185,6 @@ error_drop_packet:
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_n
.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,