[    1.672561] ip (241) used greatest stack depth: 12352 bytes left
[    2.109447] ip (279) used greatest stack depth: 12320 bytes left
[   10.333837] ip (1142) used greatest stack depth: 12304 bytes left
[   20.142623] ip (2496) used greatest stack depth: 12272 bytes left
[ 1108.707586] blackhole_netdev_xmit(): Dropping skb.
[ 1108.707647] blackhole_netdev_xmit(): Dropping skb.
[ 1108.707678] blackhole_netdev_xmit(): Dropping skb.
[ 1108.707709] blackhole_netdev_xmit(): Dropping skb.