[    1.842615] ip (245) used greatest stack depth: 12376 bytes left
[    2.367442] ip (276) used greatest stack depth: 12344 bytes left
[   13.332975] ip (1364) used greatest stack depth: 12328 bytes left
[   13.806773] ip (1392) used greatest stack depth: 12072 bytes left
[ 1108.536569] blackhole_netdev_xmit(): Dropping skb.
[ 1108.536646] blackhole_netdev_xmit(): Dropping skb.
[ 1108.536680] blackhole_netdev_xmit(): Dropping skb.
[ 1108.536714] blackhole_netdev_xmit(): Dropping skb.