[    1.769215] ip (242) used greatest stack depth: 12352 bytes left
[    2.336354] ip (276) used greatest stack depth: 12320 bytes left
[  748.454706] blackhole_netdev_xmit(): Dropping skb.
[  748.454771] blackhole_netdev_xmit(): Dropping skb.
[  748.454805] blackhole_netdev_xmit(): Dropping skb.
[  748.454837] blackhole_netdev_xmit(): Dropping skb.