Thermal-Aware Scheduling for MPSoC in the Avionics Domain: Tooling and Initial Results

The demand for high-performance computing leads to the adoption of modern Multi-Processor System-on-Chip platforms in the avionics domain, where many applications are safetycritical. To fulfill the safety requirements, it is vital to avoid the platform's overheating. In this paper, we propose a task mapping method, MultiPAWS, for thermal-aware allocation of the safety-critical avionics workloads under time isolation constraints. With the help of MultiPAWS, we jointly find an optimal number of scheduling windows and their lengths and optimal mapping of the workload to these windows and available CPU cores. To guide the optimization, we introduce a thermal model based on power-characteristic coefficients, which we experimentally identify for a benchmark dataset on NXP i.MX8QuadMax platform (based on ARMv8 big.LITTLE architecture). Furthermore, to mimic the execution of safety-critical avionics applications, we introduce DEmOS, an open-source Linux-based scheduler. DEmOS provides a time-partitioned scheduling similar to the ARINC 653 standard. We use DEmOS for the experimental evaluation on the i.MX8 platform. The experimental results suggest that MultiPAWS achieves over a 12% decrease of the platform temperature compared to the minimum-utilization-based approach. Moreover, we demonstrate how MultiPAWS can be used in design space exploration for finding the trade-off between the platform temperature and the length of the scheduling hyper-period.