[    2.082088] ip (277) used greatest stack depth: 12320 bytes left
[    9.253301] ip (1087) used greatest stack depth: 12128 bytes left
[  499.807882] hrtimer: interrupt took 8480704 ns
[  685.497695] blackhole_netdev_xmit(): Dropping skb.
[  685.497764] blackhole_netdev_xmit(): Dropping skb.
[  685.497807] blackhole_netdev_xmit(): Dropping skb.
[  685.497846] blackhole_netdev_xmit(): Dropping skb.