[    1.800839] ip (240) used greatest stack depth: 12352 bytes left
[    2.424791] ip (274) used greatest stack depth: 12320 bytes left
[   25.117283] ip (2493) used greatest stack depth: 12240 bytes left
[ 1147.058863] blackhole_netdev_xmit(): Dropping skb.
[ 1147.058949] blackhole_netdev_xmit(): Dropping skb.
[ 1147.058998] blackhole_netdev_xmit(): Dropping skb.
[ 1147.059049] blackhole_netdev_xmit(): Dropping skb.