language: en

Performance Measurements of the Multimedia Testbed on Real-Time Mach

Roger B. Dannenberg, David B. Anderson, Tom Neuendorffer, Dean Rubine
April 1994 CMU-CS-94-141
School of Computer Science Carnegie Mellon University
Pittsburgh, PA 15213-3890

Abstract Multimedia has generated widespread interest in real-time support within general purpose operating systems. Multimedia also places new demands on operating systems for interprocess communication. The Multimedia Testbed is a set of applications that stress consistent low-latency response and efficient interprocess communication for large blocks of data. The Multimedia Testbed was ported to Real-Time Mach in the hopes of providing predictable low-latency response and, consequently, good synchronization and low jitter as required for multimedia applications. Our work compares the performance of Real-Time Mach with that of Mach 3.0. Although the fixed-priority scheduling of Real-Time Mach is a substantial improvement, user threads are still preempted by device drivers, and the overall real-time performance is not suitable for multimedia applications. We discuss areas where Real-Time Mach needs improvement.

[This research was performed by the Carnegie Mellon Information Technology Center and supported by the IBM Corporation.]