[    2.058380] ip (244) used greatest stack depth: 12376 bytes left
[    2.755862] ip (278) used greatest stack depth: 12352 bytes left
[    2.814682] ip (282) used greatest stack depth: 12344 bytes left
[   11.324051] ip (953) used greatest stack depth: 12296 bytes left
[ 1128.066463] blackhole_netdev_xmit(): Dropping skb.
[ 1128.066531] blackhole_netdev_xmit(): Dropping skb.
[ 1128.066569] blackhole_netdev_xmit(): Dropping skb.
[ 1128.066604] blackhole_netdev_xmit(): Dropping skb.