Blocking analysis of suspension-based protocols for parallel real-time tasks under global fixed-priority scheduling

Abstract

With the wide use of multiprocessor architecture, parallel tasks have been receiving growing attention in both industry and academia. In real-time systems, the scheduling and synchronization that ensure predictable task execution and resource access are of utmost importance. Although the scheduling of (independent) parallel tasks is widely studied in recent years, few works have been done for the synchronization with intra-task parallelism. In particular, the performance of the classical priority inheritance mechanism is still unfathomed for parallel tasks. In this paper, we extend the Priority Inheritance Protocol (PIP) and the Flexible Multiprocessor Locking Protocol (FMLP) for real-time parallel tasks (i.e., called P-PIP and P-FMLP respectively) under the global fixed-priority scheduling, and present the blocking analysis for both protocols with the state-of-the-art linear optimization technique. Empirical evaluations show that the P-PIP outperformed the P-FMLP with increasing shared resource contentions. • This paper first studies the synchronization of parallel tasks under global scheduling. • This paper proposes a unified analysis framework under the global scheduling. • A Mixed Integer Linear Programming technique is used to reduce analytical pessimism.