[    1.709862] ip (241) used greatest stack depth: 12352 bytes left
[    2.124873] ip (275) used greatest stack depth: 12320 bytes left
[    7.218416] ip (747) used greatest stack depth: 12304 bytes left
[   20.688472] ip (2628) used greatest stack depth: 12272 bytes left
[  622.723377] ip (11264) used greatest stack depth: 12048 bytes left
[  902.440454] blackhole_netdev_xmit(): Dropping skb.
[  902.440567] blackhole_netdev_xmit(): Dropping skb.
[  902.440599] blackhole_netdev_xmit(): Dropping skb.
[  902.440631] blackhole_netdev_xmit(): Dropping skb.