[    2.505277] ip (281) used greatest stack depth: 12344 bytes left
[    2.715849] ip (295) used greatest stack depth: 12328 bytes left
[  648.665121] ip (22591) used greatest stack depth: 12320 bytes left
[ 1141.972434] blackhole_netdev_xmit(): Dropping skb.
[ 1141.972514] blackhole_netdev_xmit(): Dropping skb.
[ 1141.972559] blackhole_netdev_xmit(): Dropping skb.
[ 1141.972595] blackhole_netdev_xmit(): Dropping skb.