Discrete Frequency Selection of Frame-Based Stochastic Real-Time Tasks

TL;DR

This paper introduces a schedulability condition for frame-based stochastic real-time tasks and proposes a discrete frequency selection approach that significantly improves energy efficiency while ensuring task schedulability.

Contribution

It presents the first schedulability condition for stochastic real-time tasks and adapts continuous-speed methods to discrete systems with proven energy savings.

Findings

Energy savings of over 20% demonstrated in simulations

Schedulability condition ensures reliable task scheduling in stochastic systems

Effective adaptation of continuous-speed methods to discrete systems

Abstract

Energy-efficient real-time task scheduling has been actively explored in the past decade. Different from the past work, this paper considers schedulability conditions for stochastic real-time tasks. A schedulability condition is first presented for frame-based stochastic real-time tasks, and several algorithms are also examined to check the schedulability of a given strategy. An approach is then proposed based on the schedulability condition to adapt a continuous-speed-based method to a discrete-speed system. The approach is able to stay as close as possible to the continuous-speed-based method, but still guaranteeing the schedulability. It is shown by simulations that the energy saving can be more than 20% for some system configurations