tree 45219d6edd985eda79fb0410017df520546c4ec1
parent 0825ce70318e9c576acbdd5ceb4a8d563263cf8f
author Eric Dumazet <edumazet@google.com> 1537568872 -0700
committer David S. Miller <davem@davemloft.net> 1537764925 -0700

tun: 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.

tun 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>
Signed-off-by: David S. Miller <davem@davemloft.net>