[    2.365753] ip (273) used greatest stack depth: 12344 bytes left
[    4.116441] ip (396) used greatest stack depth: 12328 bytes left
[    4.719249] ip (438) used greatest stack depth: 12296 bytes left
[ 1078.916360] blackhole_netdev_xmit(): Dropping skb.
[ 1078.916452] blackhole_netdev_xmit(): Dropping skb.
[ 1078.916495] blackhole_netdev_xmit(): Dropping skb.
[ 1078.916540] blackhole_netdev_xmit(): Dropping skb.