[    2.579391] ip (273) used greatest stack depth: 12160 bytes left
[   21.108474] ip (2496) used greatest stack depth: 12032 bytes left
[ 1029.438647] blackhole_netdev_xmit(): Dropping skb.
[ 1029.438732] blackhole_netdev_xmit(): Dropping skb.
[ 1029.438783] blackhole_netdev_xmit(): Dropping skb.
[ 1029.438824] blackhole_netdev_xmit(): Dropping skb.