Predictable scheduling for digital audio

This paper presents results from applying the Rialto/ NT scheduler to some real Windows 2000 application scenarios. We report on two aspects of this work. First, we studied the reliability of an audio player application and the middleware and kernel components running beneath it in order to assess its reliability under various concurrent application loads. Then we added CPU Reservations to portions of the workload in order to determine if doing so would increase playback reliability under workloads in which problems were previously seen. We report on the benefits and problems observed when using reservations in these real-world scenarios. We also describe the methodologies we used to analyze the real-time behavior of the operating system and applications, including the use of instrumented kernels to produce execution traces. Finally, we describe several improvements in the Rialto/NT implementation that have been made since the system was originally described.