[    1.723316] ip (245) used greatest stack depth: 12352 bytes left
[    2.087844] ip (276) used greatest stack depth: 12320 bytes left
[    4.344609] ip (412) used greatest stack depth: 12304 bytes left
[   18.158798] ip (2220) used greatest stack depth: 12160 bytes left
[   20.453692] ip (2372) used greatest stack depth: 12128 bytes left
[ 1127.404336] blackhole_netdev_xmit(): Dropping skb.
[ 1127.404432] blackhole_netdev_xmit(): Dropping skb.
[ 1127.404482] blackhole_netdev_xmit(): Dropping skb.
[ 1127.404523] blackhole_netdev_xmit(): Dropping skb.