[    1.986334] ip (241) used greatest stack depth: 12368 bytes left
[    2.550310] ip (275) used greatest stack depth: 12336 bytes left
[    4.562273] ip (408) used greatest stack depth: 12320 bytes left
[  630.935705] ip (11617) used greatest stack depth: 12264 bytes left
[  910.401441] blackhole_netdev_xmit(): Dropping skb.
[  910.401505] blackhole_netdev_xmit(): Dropping skb.
[  910.401541] blackhole_netdev_xmit(): Dropping skb.
[  910.401583] blackhole_netdev_xmit(): Dropping skb.