[    2.235959] ip (275) used greatest stack depth: 12320 bytes left
[    7.549749] ip (753) used greatest stack depth: 12304 bytes left
[  636.336639] ip (16023) used greatest stack depth: 12272 bytes left
[  643.901909] blackhole_netdev_xmit(): Dropping skb.
[  643.901968] blackhole_netdev_xmit(): Dropping skb.
[  643.902017] blackhole_netdev_xmit(): Dropping skb.
[  643.902064] blackhole_netdev_xmit(): Dropping skb.
[  815.869962] blackhole_netdev_xmit(): Dropping skb.
[  815.870030] blackhole_netdev_xmit(): Dropping skb.
[  815.870077] blackhole_netdev_xmit(): Dropping skb.
[  815.870125] blackhole_netdev_xmit(): Dropping skb.
[  872.976820] blackhole_netdev_xmit(): Dropping skb.
[  872.976903] blackhole_netdev_xmit(): Dropping skb.
[  872.976940] blackhole_netdev_xmit(): Dropping skb.
[  872.976976] blackhole_netdev_xmit(): Dropping skb.