[    2.203379] ip (242) used greatest stack depth: 12368 bytes left
[    2.926702] ip (276) used greatest stack depth: 12336 bytes left
[    8.932993] ip (648) used greatest stack depth: 12160 bytes left
[   23.375771] ip (2140) used greatest stack depth: 12048 bytes left
[ 1172.640590] blackhole_netdev_xmit(): Dropping skb.
[ 1172.640653] blackhole_netdev_xmit(): Dropping skb.
[ 1172.640684] blackhole_netdev_xmit(): Dropping skb.
[ 1172.640718] blackhole_netdev_xmit(): Dropping skb.