[    2.202295] ip (243) used greatest stack depth: 12352 bytes left
[    2.858942] ip (277) used greatest stack depth: 12320 bytes left
[  730.796384] blackhole_netdev_xmit(): Dropping skb.
[  730.796449] blackhole_netdev_xmit(): Dropping skb.
[  730.796483] blackhole_netdev_xmit(): Dropping skb.
[  730.796511] blackhole_netdev_xmit(): Dropping skb.