[    2.150237] ip (246) used greatest stack depth: 12376 bytes left
[    2.915087] ip (280) used greatest stack depth: 12360 bytes left
[    3.169451] ip (294) used greatest stack depth: 12344 bytes left
[  777.217844] blackhole_netdev_xmit(): Dropping skb.
[  777.217934] blackhole_netdev_xmit(): Dropping skb.
[  777.217978] blackhole_netdev_xmit(): Dropping skb.
[  777.218022] blackhole_netdev_xmit(): Dropping skb.