[    2.012515] ip (240) used greatest stack depth: 12376 bytes left
[    2.643328] ip (274) used greatest stack depth: 12344 bytes left
[   20.142964] ip (2102) used greatest stack depth: 12328 bytes left
[  705.647202] blackhole_netdev_xmit(): Dropping skb.
[  705.647276] blackhole_netdev_xmit(): Dropping skb.
[  705.647330] blackhole_netdev_xmit(): Dropping skb.
[  705.647370] blackhole_netdev_xmit(): Dropping skb.