[    2.548491] ip (275) used greatest stack depth: 12320 bytes left
[  712.372351] blackhole_netdev_xmit(): Dropping skb.
[  712.372433] blackhole_netdev_xmit(): Dropping skb.
[  712.372489] blackhole_netdev_xmit(): Dropping skb.
[  712.372545] blackhole_netdev_xmit(): Dropping skb.