[    2.163541] ip (275) used greatest stack depth: 12320 bytes left
[    9.712275] ip (1077) used greatest stack depth: 12048 bytes left
[  924.848517] blackhole_netdev_xmit(): Dropping skb.
[  924.848585] blackhole_netdev_xmit(): Dropping skb.
[  924.848619] blackhole_netdev_xmit(): Dropping skb.
[  924.848656] blackhole_netdev_xmit(): Dropping skb.