[    2.030841] ip (243) used greatest stack depth: 12376 bytes left
[    2.651350] ip (277) used greatest stack depth: 12344 bytes left
[   23.615076] ip (2368) used greatest stack depth: 12288 bytes left
[  724.535908] blackhole_netdev_xmit(): Dropping skb.
[  724.536012] blackhole_netdev_xmit(): Dropping skb.
[  724.536045] blackhole_netdev_xmit(): Dropping skb.
[  724.536079] blackhole_netdev_xmit(): Dropping skb.