hv_netvsc: remove ndo_poll_controller
authorStephen Hemminger <stephen@networkplumber.org>
Sat, 29 Sep 2018 12:52:56 +0000 (14:52 +0200)
committerDavid S. Miller <davem@davemloft.net>
Wed, 3 Oct 2018 05:57:34 +0000 (22:57 -0700)
commit2a7f8c3b1d3feedee3aa319ac220cbde3725b5d5
treeeb0dae451ce25abf6a85426f3cdf5543d7c12dde
parentd777f552fcc17b208e63df8b30293e01d9e4971f
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 <sthemmin@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Eric Dumazet <edumazet@google.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/hyperv/netvsc_drv.c