[    1.867285] ip (243) used greatest stack depth: 12376 bytes left
[    2.511385] ip (277) used greatest stack depth: 12360 bytes left
[    2.565450] ip (281) used greatest stack depth: 12344 bytes left
[   21.552210] ip (2231) used greatest stack depth: 12200 bytes left
[ 1034.299785] blackhole_netdev_xmit(): Dropping skb.
[ 1034.299883] blackhole_netdev_xmit(): Dropping skb.
[ 1034.299926] blackhole_netdev_xmit(): Dropping skb.
[ 1034.299975] blackhole_netdev_xmit(): Dropping skb.