[    2.558213] ip (276) used greatest stack depth: 12360 bytes left
[    2.604645] ip (280) used greatest stack depth: 12344 bytes left
[  884.821584] blackhole_netdev_xmit(): Dropping skb.
[  884.821658] blackhole_netdev_xmit(): Dropping skb.
[  884.821709] blackhole_netdev_xmit(): Dropping skb.
[  884.821755] blackhole_netdev_xmit(): Dropping skb.