[    2.572087] ip (240) used greatest stack depth: 12352 bytes left
[    3.250916] ip (274) used greatest stack depth: 12320 bytes left
[   28.114349] ip (2611) used greatest stack depth: 12160 bytes left
[  957.736226] blackhole_netdev_xmit(): Dropping skb.
[  957.736396] blackhole_netdev_xmit(): Dropping skb.
[  957.736434] blackhole_netdev_xmit(): Dropping skb.
[  957.736474] blackhole_netdev_xmit(): Dropping skb.