TMDS: Temperature-aware Makespan Minimizing DAG Scheduler for Heterogeneous Distributed Systems

To meet application-specific performance demands, recent embedded platforms often involve the use of intricate micro-architectural designs and very small feature sizes leading to complex chips with multi-million gates. Such ultra-high gate densities often make these chips susceptible to inappropriate surges in core temperatures. Temperature surges above a specific threshold may throttle processor performance, enhance cooling costs, and reduce processor life expectancy. This work proposes a generic temperature management strategy that can be easily employed to adapt existing state-of-the-art task graph schedulers so that schedules generated by them never violate stipulated thermal bounds. The overall temperature-aware task graph scheduling problem has first been formally modeled as a constraint optimization formulation whose solution is shown to be prohibitively expensive in terms of computational overheads. Based on insights obtained through the formal model, a new fast and efficient heuristic algorithm called TMDS has been designed. Experimental evaluation over diverse test case scenarios shows that TMDS is able to deliver lower schedule lengths compared to the temperature-aware versions of four prominent makespan minimizing algorithms, namely, HEFT, PEFT, PPTS, and PSLS. Additionally, a case study with an adaptive cruise controller in automotive systems has been included to exhibit the applicability of TMDS in real-world settings.