[    2.534400] ip (282) used greatest stack depth: 12344 bytes left
[    5.937841] ip (449) used greatest stack depth: 12304 bytes left
[  637.805124] ip (31263) used greatest stack depth: 12192 bytes left
[  860.312948] blackhole_netdev_xmit(): Dropping skb.
[  860.313015] blackhole_netdev_xmit(): Dropping skb.
[  860.313049] blackhole_netdev_xmit(): Dropping skb.
[  860.313083] blackhole_netdev_xmit(): Dropping skb.