[    1.856419] ip (242) used greatest stack depth: 12376 bytes left
[    2.440088] ip (276) used greatest stack depth: 12344 bytes left
[   15.776423] ip (1406) used greatest stack depth: 12184 bytes left
[  757.059703] blackhole_netdev_xmit(): Dropping skb.
[  757.059773] blackhole_netdev_xmit(): Dropping skb.
[  757.059814] blackhole_netdev_xmit(): Dropping skb.
[  757.059874] blackhole_netdev_xmit(): Dropping skb.