The purpose of this code is to test the context switch cost on both host side
and VM2VM.

Two type of threads are created. One type of thread is to emulate a DPDK apps
that busy loop on something. Another thread is to emulate the packet generator.
The pkggen thread send the request to the DPDKapp thread for the busy loops
times, just like a packet generator send the packet to the DPDK application.
The DPDk busy loop according to input from pktgen thread. Then we check how
many busy loop requirement is not met, i.e. packet lost, and how many busy loop
achieved in total.

With this setup, we emulate the elastic DPDK scenario.

To do this on the VM environment is a little bit more tricky since the DPDkapps
will be inside a VM and the pktgen thread will be in host. But I think we can
still achieve it through some share memory between host/VM.