[    1.765710] ip (243) used greatest stack depth: 12592 bytes left
[    2.208638] ip (274) used greatest stack depth: 12320 bytes left
[   16.272551] ip (2185) used greatest stack depth: 12304 bytes left
[  671.930866] blackhole_netdev_xmit(): Dropping skb.
[  671.930942] blackhole_netdev_xmit(): Dropping skb.
[  671.930995] blackhole_netdev_xmit(): Dropping skb.
[  671.931030] blackhole_netdev_xmit(): Dropping skb.
[  971.996065] blackhole_netdev_xmit(): Dropping skb.
[  971.996131] blackhole_netdev_xmit(): Dropping skb.
[  971.996164] blackhole_netdev_xmit(): Dropping skb.
[  971.996205] blackhole_netdev_xmit(): Dropping skb.