Programming language Virtual Machines (VM)s are now widely used, from server applications to web browsers. Published benchmarks regularly show that VMs can optimise programs to the same degree as, and often substantially better than, traditional static compilers.
Yet, there are still people who are unhappy with the VMs they use. Frequently their programs don't run anywhere near as fast as benchmarks suggest; sometimes their programs even run slower than more naive language implementations. Often our reaction is to tell such users that their programs are "wrong" and that they should fix them.
This talk takes a detailed look at VM performance, based on a lengthy experiment: we not only uncovered unexpected patterns of behaviour, but found that VMs perform poorly far more often than previously thought. I will draw on some of my own experiences to suggest how we may have gotten into such a pickle. Finally, I will offer some suggestions as to how we might be able to make more VM users more happy in the future.Visit the event web page
Cornwallis South West,
University of Kent,