[    2.435549] ip (273) used greatest stack depth: 12344 bytes left
[   10.788028] ip (1066) used greatest stack depth: 12184 bytes left
[  854.288055] blackhole_netdev_xmit(): Dropping skb.
[  854.288133] blackhole_netdev_xmit(): Dropping skb.
[  854.288173] blackhole_netdev_xmit(): Dropping skb.
[  854.288212] blackhole_netdev_xmit(): Dropping skb.