[    1.845290] ip (244) used greatest stack depth: 12608 bytes left
[    2.408956] ip (278) used greatest stack depth: 12352 bytes left
[    2.450974] ip (282) used greatest stack depth: 12336 bytes left
[    5.450361] ip (441) used greatest stack depth: 12296 bytes left
[   10.444244] ip (952) used greatest stack depth: 12024 bytes left
[ 1146.094198] blackhole_netdev_xmit(): Dropping skb.
[ 1146.094277] blackhole_netdev_xmit(): Dropping skb.
[ 1146.094321] blackhole_netdev_xmit(): Dropping skb.
[ 1146.094366] blackhole_netdev_xmit(): Dropping skb.