[    1.894210] ip (242) used greatest stack depth: 12376 bytes left
[    2.557757] ip (276) used greatest stack depth: 12344 bytes left
[  978.555661] blackhole_netdev_xmit(): Dropping skb.
[  978.555721] blackhole_netdev_xmit(): Dropping skb.
[  978.555754] blackhole_netdev_xmit(): Dropping skb.
[  978.555793] blackhole_netdev_xmit(): Dropping skb.