[    1.618586] ip (242) used greatest stack depth: 12352 bytes left
[    2.007315] ip (276) used greatest stack depth: 12320 bytes left
[   10.389117] ip (1171) used greatest stack depth: 12272 bytes left
[  789.390524] blackhole_netdev_xmit(): Dropping skb.
[  789.390620] blackhole_netdev_xmit(): Dropping skb.
[  789.390674] blackhole_netdev_xmit(): Dropping skb.
[  789.390726] blackhole_netdev_xmit(): Dropping skb.