And if you want to use kni, you should do one of two action:
1. `insmod rte_kni.ko carrier=on` while init dpdk running environment.
2. or run `echo 1 > /sys/class/net/veth0/carrier` after enable veth0 up.
Refer #401, but this is not the real reason of #401, it is the DPDK's ENA driver can't work correctly in multi-processes.
Changes:
1. This version is downloaded from
https://fast.dpdk.org/rel/dpdk-17.11.2.tar.xz.
2. Adapt the new interface `rte_ring_dequeue_burst`.
3. Change the type of `port_id` from uint8_t to uint16_t.
4. Just link libdpdk.a instead of the other libaries.
5. Install libnuma-dev first.
6. Update the documents.