[    2.079584] ip (275) used greatest stack depth: 12320 bytes left
[    6.480937] ip (646) used greatest stack depth: 12224 bytes left
[    6.513492] ip (650) used greatest stack depth: 12144 bytes left
[ 1201.321753] blackhole_netdev_xmit(): Dropping skb.
[ 1201.321830] blackhole_netdev_xmit(): Dropping skb.
[ 1201.321880] blackhole_netdev_xmit(): Dropping skb.
[ 1201.321938] blackhole_netdev_xmit(): Dropping skb.