[    1.872668] ip (243) used greatest stack depth: 12416 bytes left
[    1.902386] ip (246) used greatest stack depth: 12352 bytes left
[    2.376485] ip (277) used greatest stack depth: 12320 bytes left
[   10.977463] ip (1142) used greatest stack depth: 12304 bytes left
[  869.752939] blackhole_netdev_xmit(): Dropping skb.
[  869.753007] blackhole_netdev_xmit(): Dropping skb.
[  869.753044] blackhole_netdev_xmit(): Dropping skb.
[  869.753077] blackhole_netdev_xmit(): Dropping skb.