[    1.584632] ip (241) used greatest stack depth: 12352 bytes left
[    1.951464] ip (275) used greatest stack depth: 12320 bytes left
[   17.505946] ip (2340) used greatest stack depth: 12304 bytes left
[ 1131.455461] blackhole_netdev_xmit(): Dropping skb.
[ 1131.455542] blackhole_netdev_xmit(): Dropping skb.
[ 1131.455576] blackhole_netdev_xmit(): Dropping skb.
[ 1131.455607] blackhole_netdev_xmit(): Dropping skb.