[    2.639530] ip (276) used greatest stack depth: 12320 bytes left
[    2.698372] ip (280) used greatest stack depth: 12272 bytes left
[   25.999269] ip (2380) used greatest stack depth: 12144 bytes left
[  962.184785] blackhole_netdev_xmit(): Dropping skb.
[  962.184910] blackhole_netdev_xmit(): Dropping skb.
[  962.184947] blackhole_netdev_xmit(): Dropping skb.
[  962.184979] blackhole_netdev_xmit(): Dropping skb.