[    1.897837] ip (243) used greatest stack depth: 12384 bytes left
[    2.443894] ip (277) used greatest stack depth: 12352 bytes left
[  635.229009] ip (19551) used greatest stack depth: 12336 bytes left
[  902.339089] blackhole_netdev_xmit(): Dropping skb.
[  902.339166] blackhole_netdev_xmit(): Dropping skb.
[  902.339216] blackhole_netdev_xmit(): Dropping skb.
[  902.339265] blackhole_netdev_xmit(): Dropping skb.
[ 1126.324325] blackhole_netdev_xmit(): Dropping skb.
[ 1126.324397] blackhole_netdev_xmit(): Dropping skb.
[ 1126.324426] blackhole_netdev_xmit(): Dropping skb.
[ 1126.324459] blackhole_netdev_xmit(): Dropping skb.