Optimising the Scheduling of System Level Logical Execution Time Systems

Abstract

The paradigm of Logical Execution Time (LET) tasks is widely adopted by major tool vendors for designing deterministic and time-predictable software in multi-core systems, particularly in the automotive industry. To extend the use of LET in distributed environments, System Level Logical Execution Time (SL-LET) has been developed to effectively manage communication and delays between networked devices. However, there is currently a lack of open-source tools available for SL-LET, and the task allocation and scheduling problem for SL-LET remains unsolved. To address these concerns, we introduces a novel Integer Linear Programming (ILP)-based optimisation approach for SL-LET task allocation and scheduling, focusing on minimising core utilisation and average system response times. To illustrate the effectiveness of the approach, we benchmark our ILP-based solution against a traditional core allocation heuristic across multiple task sets. Through this evaluation, our approach, when compared to the heuristic, is able to demonstrate average response times that are 26.9% smaller.