[    2.785633] ip (278) used greatest stack depth: 12344 bytes left
[    3.016434] ip (292) used greatest stack depth: 12328 bytes left
[   16.318207] ip (1365) used greatest stack depth: 12312 bytes left
[   17.009471] ip (1402) used greatest stack depth: 12176 bytes left
[  891.404932] blackhole_netdev_xmit(): Dropping skb.
[  891.405003] blackhole_netdev_xmit(): Dropping skb.
[  891.405036] blackhole_netdev_xmit(): Dropping skb.
[  891.405069] blackhole_netdev_xmit(): Dropping skb.