[    2.044090] ip (277) used greatest stack depth: 12320 bytes left
[   10.065249] ip (1144) used greatest stack depth: 12304 bytes left
[  869.113316] blackhole_netdev_xmit(): Dropping skb.
[  869.113403] blackhole_netdev_xmit(): Dropping skb.
[  869.113456] blackhole_netdev_xmit(): Dropping skb.
[  869.113508] blackhole_netdev_xmit(): Dropping skb.