[    2.300022] ip (275) used greatest stack depth: 12320 bytes left
[   13.498628] ip (1396) used greatest stack depth: 12048 bytes left
[  899.785141] blackhole_netdev_xmit(): Dropping skb.
[  899.785207] blackhole_netdev_xmit(): Dropping skb.
[  899.785244] blackhole_netdev_xmit(): Dropping skb.
[  899.785283] blackhole_netdev_xmit(): Dropping skb.