[    2.513823] ip (275) used greatest stack depth: 12344 bytes left
[   14.786546] ip (1406) used greatest stack depth: 12296 bytes left
[  740.546718] blackhole_netdev_xmit(): Dropping skb.
[  740.546782] blackhole_netdev_xmit(): Dropping skb.
[  740.546816] blackhole_netdev_xmit(): Dropping skb.
[  740.546848] blackhole_netdev_xmit(): Dropping skb.