[    2.379615] ip (274) used greatest stack depth: 12320 bytes left
[   24.169250] ip (2497) used greatest stack depth: 12144 bytes left
[  881.988711] blackhole_netdev_xmit(): Dropping skb.
[  881.988769] blackhole_netdev_xmit(): Dropping skb.
[  881.988801] blackhole_netdev_xmit(): Dropping skb.
[  881.988835] blackhole_netdev_xmit(): Dropping skb.