[    2.672955] ip (277) used greatest stack depth: 12352 bytes left
[    8.521238] ip (662) used greatest stack depth: 12344 bytes left
[   23.588514] ip (2216) used greatest stack depth: 12312 bytes left
[  653.147936] ip (24208) used greatest stack depth: 12200 bytes left
[  919.840111] blackhole_netdev_xmit(): Dropping skb.
[  919.840174] blackhole_netdev_xmit(): Dropping skb.
[  919.840209] blackhole_netdev_xmit(): Dropping skb.
[  919.840245] blackhole_netdev_xmit(): Dropping skb.