[    1.914997] ip (242) used greatest stack depth: 12352 bytes left
[    2.585676] ip (276) used greatest stack depth: 12320 bytes left
[   10.428896] ip (796) used greatest stack depth: 12160 bytes left
[ 1218.541284] blackhole_netdev_xmit(): Dropping skb.
[ 1218.541373] blackhole_netdev_xmit(): Dropping skb.
[ 1218.541424] blackhole_netdev_xmit(): Dropping skb.
[ 1218.541473] blackhole_netdev_xmit(): Dropping skb.