[    1.969474] ip (246) used greatest stack depth: 12360 bytes left
[    2.594389] ip (280) used greatest stack depth: 12344 bytes left
[    2.646418] ip (284) used greatest stack depth: 12328 bytes left
[    9.413471] ip (758) used greatest stack depth: 12312 bytes left
[   24.384730] ip (2224) used greatest stack depth: 12176 bytes left
[  832.083438] blackhole_netdev_xmit(): Dropping skb.
[  832.083511] blackhole_netdev_xmit(): Dropping skb.
[  832.083546] blackhole_netdev_xmit(): Dropping skb.
[  832.083580] blackhole_netdev_xmit(): Dropping skb.