[    2.660799] ip (275) used greatest stack depth: 12336 bytes left
[   29.049311] ip (2584) used greatest stack depth: 12320 bytes left
[  776.600032] blackhole_netdev_xmit(): Dropping skb.
[  776.600112] blackhole_netdev_xmit(): Dropping skb.
[  776.600158] blackhole_netdev_xmit(): Dropping skb.
[  776.600213] blackhole_netdev_xmit(): Dropping skb.