[    2.447672] ip (275) used greatest stack depth: 12336 bytes left
[  631.404666] ip (4182) used greatest stack depth: 12320 bytes left
[  875.728359] blackhole_netdev_xmit(): Dropping skb.
[  875.728423] blackhole_netdev_xmit(): Dropping skb.
[  875.728456] blackhole_netdev_xmit(): Dropping skb.
[  875.728490] blackhole_netdev_xmit(): Dropping skb.
[ 1089.876536] blackhole_netdev_xmit(): Dropping skb.
[ 1089.876604] blackhole_netdev_xmit(): Dropping skb.
[ 1089.876639] blackhole_netdev_xmit(): Dropping skb.
[ 1089.876677] blackhole_netdev_xmit(): Dropping skb.