Improving schedulabity on the SMT Multicore Intel Xeon e-5645 under real-time systems

Abstract

[EN] Traditionally, the study of real-time systems has mainly focused on hardware systems simple enough that make its study easy; for instance, system modeling and schedulability analysis. This implies that the processors usually included in real-time systems do not implement advanced performance features. The increasing number of functionalities in real-time embedded systems (e.g. smartphones), however, is resulting in a processor convergence between high performance systems and embedded systems. Therefore it is expected that advanced SMT processors will be soon deployed in realtime devices. In this context, the use of analytical models may become inappropriate due to its lack of accuracy to study the behavior of modern and future real-time systems. In this work, we propose a new scheduling framework for SMT multicore processors to cover the design stages of real-time scheduling policies. The proposed framework works on the Linux operating system and allows changing the scheduling policy as well as the job-to-core allocation policy without modifying the kernel, which facilitates and makes faster the development of new scheduling proposals. Two case studies on the Intel Xeon E5645 are also presented for illustrative purposes. Two well-known real-time scheduling algorithms: Earliest Deadline First (EDF) and Rate Monotonic (RM) have been implemented and studied by executing real benchmarks.