[    2.185974] ip (242) used greatest stack depth: 12416 bytes left
[    2.722310] ip (276) used greatest stack depth: 12320 bytes left
[    5.980587] ip (453) used greatest stack depth: 12272 bytes left
[  648.947182] ip (23814) used greatest stack depth: 12048 bytes left
[  989.173129] blackhole_netdev_xmit(): Dropping skb.
[  989.173204] blackhole_netdev_xmit(): Dropping skb.
[  989.173254] blackhole_netdev_xmit(): Dropping skb.
[  989.173311] blackhole_netdev_xmit(): Dropping skb.