[    2.138455] ip (253) used greatest stack depth: 12328 bytes left
[  633.500811] ip (22044) used greatest stack depth: 12304 bytes left
[  697.908491] blackhole_netdev_xmit(): Dropping skb.
[  697.908555] blackhole_netdev_xmit(): Dropping skb.
[  697.908587] blackhole_netdev_xmit(): Dropping skb.
[  697.908629] blackhole_netdev_xmit(): Dropping skb.
[ 1189.977509] blackhole_netdev_xmit(): Dropping skb.
[ 1189.977583] blackhole_netdev_xmit(): Dropping skb.
[ 1189.977614] blackhole_netdev_xmit(): Dropping skb.
[ 1189.977640] blackhole_netdev_xmit(): Dropping skb.