An Adaptive Value-Based Scheduler and Its RT-Linux Implementation

Abstract

Abstract. In dynamic real-time systems, value-based scheduling aims to achieve graceful degradation during overloads, in addition to maintaining a high schedulability during normal and underloads. The objective of this paper is twofold: (1) to propose an adaptive value-based scheduler for multiprocessor real-time systems aimed at maintaining a high system value with less deadline misses, and (2) to present the implementation of the proposed scheduler in a Linux based real-time operating system, RT-Linux, which in its current form does not employ a notion of task value. We evaluate the performance of the proposed scheduler in terms of two performance metrics, namely, "value ratio" and "success ratio" through both simulation and implementation.

Value-based scheduling in real-time systems

“…In this chapter, we present the design and implementation of the proposed adaptive valuebased scheduler (for homogeneous computing system) in RT-Linux, a real-time variant of Linux operating systems and present the results of experimental evaluation of the implemented scheduler for various ranges of workloads. A shorter version of this work can be found in [32]. The rest of the chapter is organized as follows: In section 5.2, we present the basic architecture of RT-Linux and discuss its current scheduling behavior.…”