diff options
| author |   Eric Dumazet <edumazet@google.com> | 2018-09-27 09:32:00 -0700 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2018-09-28 11:12:29 -0700 |
| commit | a4f570be654de779eaf626a79c4e0aa5a790505f (patch) | |
| tree | 78ea33a09a2817acd3a286aaa760f0db22e6af0f | |
| parent | sfc: remove ndo_poll_controller (diff) | |
| download | linux-dev-a4f570be654de779eaf626a79c4e0aa5a790505f.tar.xz linux-dev-a4f570be654de779eaf626a79c4e0aa5a790505f.zip | |
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 <edumazet@google.com>
Cc: Solarflare linux maintainers <linux-net-drivers@solarflare.com>
Cc: Edward Cree <ecree@solarflare.com>
Cc: Bert Kenward <bkenward@solarflare.com>
Acked-By: Bert Kenward <bkenward@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/net/ethernet/sfc/falcon/efx.c | 26 |
1 files changed, 0 insertions, 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 @@ -2054,29 +2054,6 @@ static void ef4_fini_napi(struct ef4_nic *efx) /************************************************************************** * - * 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, |