[    2.392827] ip (275) used greatest stack depth: 12344 bytes left
[   25.725475] ip (2569) used greatest stack depth: 12328 bytes left
[  636.647338] ip (6958) used greatest stack depth: 12184 bytes left
[  734.205633] blackhole_netdev_xmit(): Dropping skb.
[  734.205687] blackhole_netdev_xmit(): Dropping skb.
[  734.205716] blackhole_netdev_xmit(): Dropping skb.
[  734.205748] blackhole_netdev_xmit(): Dropping skb.