Performance Impact of Futex on Virtual Machines

As discovered in our previous benchmark works, a small number of workloads in PARSEC benchmark suite suffer from heavy performance loss in a virtual execution environment, of which the major loss exhibits fairly a strong connection with the thread synchronization operations. This paper examines one workload of this kind that makes heavy use of thread synchronization operations, and shows the performance impact by futex system call for applications in a virtual execution environment. By measuring the occurrence of the subroutines running at particular time costs, the most timing-decisive parts of the application in a virtual execution environment are located. Proper thread scheduling measure for a virtual execution environment are also proposed.