[    2.577766] ip (274) used greatest stack depth: 12368 bytes left
[    8.151965] ip (646) used greatest stack depth: 12352 bytes left
[  932.383541] blackhole_netdev_xmit(): Dropping skb.
[  932.383606] blackhole_netdev_xmit(): Dropping skb.
[  932.383641] blackhole_netdev_xmit(): Dropping skb.
[  932.383673] blackhole_netdev_xmit(): Dropping skb.