[    1.869039] ip (244) used greatest stack depth: 12304 bytes left
[  676.083952] blackhole_netdev_xmit(): Dropping skb.
[  676.084027] blackhole_netdev_xmit(): Dropping skb.
[  676.084074] blackhole_netdev_xmit(): Dropping skb.
[  676.084138] blackhole_netdev_xmit(): Dropping skb.