[    2.685353] ip (274) used greatest stack depth: 12344 bytes left
[  634.235487] ip (1011) used greatest stack depth: 12072 bytes left
[ 1125.660563] blackhole_netdev_xmit(): Dropping skb.
[ 1125.660636] blackhole_netdev_xmit(): Dropping skb.
[ 1125.660674] blackhole_netdev_xmit(): Dropping skb.
[ 1125.660709] blackhole_netdev_xmit(): Dropping skb.