Reducing Peak Temperature by Redistributing Idle-Time in Modern MPSoCs

Reducing heat dissipation is critical for modern multi-core systems to meet increasing computational performance requirements. In this paper, we investigate the impact of idle-time distribution on the peak temperature of Multi-processor System-on-Chip (MPSoCs) for the constrained-deadline non-preemptive task scheduling problem that is common in safety-critical systems. It is assumed that the transient thermal behavior of the platform cannot be neglected and must be modeled and accounted for by the optimization algorithms. In this context, we derive a dual-node thermal model that can be well applied to a dual-cluster i.MX8 QuadMax from NXP. Based on this model, we implement two offline optimization-based strategies, including an iterative per-core approach based on the principles presented in the related literature and a novel holistic approach. The results show that the per-core approach and the holistic approach reduce the peak temperature by 7.1% and 14% on average compared to the traditional non-thermal approach. We perform the experiments on the i.MX8 QuadMax platform to validate the applicability of the results and observe a good match between the model-based simulations and the actual physical platform measurements.