[    1.915571] ip (241) used greatest stack depth: 12376 bytes left
[    2.515571] ip (275) used greatest stack depth: 12296 bytes left
[   19.673195] ip (2138) used greatest stack depth: 12184 bytes left
[  678.160360] blackhole_netdev_xmit(): Dropping skb.
[  678.160429] blackhole_netdev_xmit(): Dropping skb.
[  678.160470] blackhole_netdev_xmit(): Dropping skb.
[  678.160505] blackhole_netdev_xmit(): Dropping skb.