[    2.355938] ip (278) used greatest stack depth: 12352 bytes left
[    7.238810] ip (650) used greatest stack depth: 12200 bytes left
[  810.418740] blackhole_netdev_xmit(): Dropping skb.
[  810.418823] blackhole_netdev_xmit(): Dropping skb.
[  810.418868] blackhole_netdev_xmit(): Dropping skb.
[  810.418906] blackhole_netdev_xmit(): Dropping skb.