Reducing application-stage latencies of interprocess communication techniques for real-time interactive systems

Abstract

Latency jitter is a pressing problem in Virtual Reality (VR) applications. This paper analyzes latency jitter caused by typical interprocess communication (IPC) techniques commonly found in today's computer systems used for VR. Test programs measure the scalability and latencies for various IPC techniques, where increasing number of threads are performing the same task concurrently. We use four different implementations on a vanilla Linux kernel as well as on a real-time (RT) Linux kernel to further assess if a RT variant of a multiuser multiprocess operating system can prevent latency spikes and how this behavior would apply to different programming languages and IPC techniques. We found that Linux RT can limit the latency jitter at the cost of throughput for certain implementations. Further, coarse grained concurrency should be employed to avoid adding up of scheduler latencies, especially for native system space IPC, while actor systems are found to support a higher degree of concurrency granularity and a higher level of abstraction.