Orchestrator: Guarding Against Voltage Emergencies in Multithreaded Applications

Voltage emergency (VE) has become a critical challenge with decreasing feature size and increasing power capacity. Destructive core interference is one main source of VE in multicore processors. We observed that the applications following single program and multiple data programming model tend to spark domain-wide destructive core interference because multiple threads exhibit similar power activity. We analyze and quantify this effect and propose one low-cost solution, Orchestrator, to avoid voltage droop synergy among cores. Orchestrator leverages the thread diversity to smooth voltage droops in multicore architectures based on thread scheduling. The thread migration impact on performance is also considered. Experimental results show that Orchestrator can significantly reduce VEs, thereby improving performance.