[    1.774846] ip (241) used greatest stack depth: 12352 bytes left
[    2.261604] ip (275) used greatest stack depth: 12320 bytes left
[    6.318658] ip (621) used greatest stack depth: 12304 bytes left
[ 1105.611797] blackhole_netdev_xmit(): Dropping skb.
[ 1105.611872] blackhole_netdev_xmit(): Dropping skb.
[ 1105.611916] blackhole_netdev_xmit(): Dropping skb.
[ 1105.611968] blackhole_netdev_xmit(): Dropping skb.