[    2.669343] ip (274) used greatest stack depth: 12344 bytes left
[    8.819390] ip (754) used greatest stack depth: 12328 bytes left
[  969.277870] blackhole_netdev_xmit(): Dropping skb.
[  969.277939] blackhole_netdev_xmit(): Dropping skb.
[  969.277974] blackhole_netdev_xmit(): Dropping skb.
[  969.278012] blackhole_netdev_xmit(): Dropping skb.