[    1.643722] ip (241) used greatest stack depth: 12352 bytes left
[    2.095235] ip (275) used greatest stack depth: 12320 bytes left
[    4.937503] ip (443) used greatest stack depth: 12272 bytes left
[   11.050542] ip (1185) used greatest stack depth: 12160 bytes left
[ 1127.578312] blackhole_netdev_xmit(): Dropping skb.
[ 1127.578480] blackhole_netdev_xmit(): Dropping skb.
[ 1127.578526] blackhole_netdev_xmit(): Dropping skb.
[ 1127.578575] blackhole_netdev_xmit(): Dropping skb.