[    1.892521] ip (251) used greatest stack depth: 12376 bytes left
[    2.440788] ip (282) used greatest stack depth: 12360 bytes left
[    2.485750] ip (286) used greatest stack depth: 12344 bytes left
[  671.535961] blackhole_netdev_xmit(): Dropping skb.
[  671.536033] blackhole_netdev_xmit(): Dropping skb.
[  671.536070] blackhole_netdev_xmit(): Dropping skb.
[  671.536112] blackhole_netdev_xmit(): Dropping skb.
[  906.868699] blackhole_netdev_xmit(): Dropping skb.
[  906.868761] blackhole_netdev_xmit(): Dropping skb.
[  906.868792] blackhole_netdev_xmit(): Dropping skb.
[  906.868835] blackhole_netdev_xmit(): Dropping skb.