[    2.223713] ip (275) used greatest stack depth: 12320 bytes left
[    6.085294] ip (620) used greatest stack depth: 12304 bytes left
[    8.990259] ip (951) used greatest stack depth: 12272 bytes left
[  759.308446] blackhole_netdev_xmit(): Dropping skb.
[  759.308558] blackhole_netdev_xmit(): Dropping skb.
[  759.308610] blackhole_netdev_xmit(): Dropping skb.
[  759.308661] blackhole_netdev_xmit(): Dropping skb.
[  916.570246] blackhole_netdev_xmit(): Dropping skb.
[  916.570315] blackhole_netdev_xmit(): Dropping skb.
[  916.570349] blackhole_netdev_xmit(): Dropping skb.
[  916.570382] blackhole_netdev_xmit(): Dropping skb.