[    1.976811] ip (243) used greatest stack depth: 12368 bytes left
[    2.559882] ip (277) used greatest stack depth: 12336 bytes left
[   21.017879] ip (2188) used greatest stack depth: 12320 bytes left
[   23.943583] ip (2372) used greatest stack depth: 12176 bytes left
[  718.481171] blackhole_netdev_xmit(): Dropping skb.
[  718.481307] blackhole_netdev_xmit(): Dropping skb.
[  718.481364] blackhole_netdev_xmit(): Dropping skb.
[  718.481413] blackhole_netdev_xmit(): Dropping skb.
[  821.473648] blackhole_netdev_xmit(): Dropping skb.
[  821.473707] blackhole_netdev_xmit(): Dropping skb.
[  821.473742] blackhole_netdev_xmit(): Dropping skb.
[  821.473777] blackhole_netdev_xmit(): Dropping skb.