[    2.312178] ip (277) used greatest stack depth: 12320 bytes left
[  634.995679] ip (12734) used greatest stack depth: 12176 bytes left
[  926.404667] blackhole_netdev_xmit(): Dropping skb.
[  926.404727] blackhole_netdev_xmit(): Dropping skb.
[  926.404762] blackhole_netdev_xmit(): Dropping skb.
[  926.404802] blackhole_netdev_xmit(): Dropping skb.