Fixed-Priority Scheduling for Two-Phase Mixed-Criticality Systems

Abstract

In this article, a two-phase execution model is proposed for mixed-criticality (MC) tasks. Different from traditional MC tasks with a computation phase only, the two-phase execution model requires a memory-access phase first to fetch the instructions and data, and then computation. Theoretical foundations are first established for a schedulability test under given memory-access and computation priority assignment. Based on the established theoretical conclusions, a two-stage priority assignment algorithm, which can find the best priority assignment for both memory-access and computation phases under fixed-priority scheduling, is further developed. Extensive experiments have been conducted and the experimental results validate the effectiveness of our proposed approach.