[    2.703572] ip (276) used greatest stack depth: 12320 bytes left
[   26.730464] ip (2381) used greatest stack depth: 12176 bytes left
[  676.534219] blackhole_netdev_xmit(): Dropping skb.
[  676.534297] blackhole_netdev_xmit(): Dropping skb.
[  676.534345] blackhole_netdev_xmit(): Dropping skb.
[  676.534385] blackhole_netdev_xmit(): Dropping skb.