[    2.470157] ip (278) used greatest stack depth: 12352 bytes left
[    2.669864] ip (292) used greatest stack depth: 12344 bytes left
[    9.323654] ip (785) used greatest stack depth: 12296 bytes left
[   24.125501] ip (2383) used greatest stack depth: 12168 bytes left
[ 1214.493389] blackhole_netdev_xmit(): Dropping skb.
[ 1214.493453] blackhole_netdev_xmit(): Dropping skb.
[ 1214.493484] blackhole_netdev_xmit(): Dropping skb.
[ 1214.493517] blackhole_netdev_xmit(): Dropping skb.