overhead measurement

[Tao Zhao <taozhao@xxxxxxxxxx>]

Hi, all

I want to measure the overhead of LVS, e.g. the additional latency imposed
by LVS instead of a traditional router. I looked up several documents
and found Zhang's paper mentioned 60us for rewriting a 536 bytes packet.
All measurements in other documents focuses on throughput instead of
latency overhead.

I believe it's not very hard to measure the latency as long as we have a
fine grain clock. Anyone knows how to get fine grain time?

Thanks,
-Tao