[    1.816856] ip (248) used greatest stack depth: 12360 bytes left
[    2.388170] ip (282) used greatest stack depth: 12344 bytes left
[    5.378485] ip (459) used greatest stack depth: 12328 bytes left
[   25.751306] ip (2373) used greatest stack depth: 12144 bytes left
[  969.220981] blackhole_netdev_xmit(): Dropping skb.
[  969.221058] blackhole_netdev_xmit(): Dropping skb.
[  969.221103] blackhole_netdev_xmit(): Dropping skb.
[  969.221162] blackhole_netdev_xmit(): Dropping skb.