[    2.353385] ip (274) used greatest stack depth: 12344 bytes left
[   11.253159] ip (1043) used greatest stack depth: 12328 bytes left
[  961.530564] blackhole_netdev_xmit(): Dropping skb.
[  961.530635] blackhole_netdev_xmit(): Dropping skb.
[  961.530683] blackhole_netdev_xmit(): Dropping skb.
[  961.530739] blackhole_netdev_xmit(): Dropping skb.