[    1.749770] ip (245) used greatest stack depth: 12376 bytes left
[    2.269879] ip (276) used greatest stack depth: 12352 bytes left
[    5.408466] ip (454) used greatest stack depth: 12344 bytes left
[  632.428852] ip (19335) used greatest stack depth: 12328 bytes left
[  676.602295] blackhole_netdev_xmit(): Dropping skb.
[  676.602377] blackhole_netdev_xmit(): Dropping skb.
[  676.602436] blackhole_netdev_xmit(): Dropping skb.
[  676.602497] blackhole_netdev_xmit(): Dropping skb.
[  954.418122] ip (20256) used greatest stack depth: 12136 bytes left
[  965.058231] blackhole_netdev_xmit(): Dropping skb.
[  965.058308] blackhole_netdev_xmit(): Dropping skb.
[  965.058352] blackhole_netdev_xmit(): Dropping skb.
[  965.058401] blackhole_netdev_xmit(): Dropping skb.