Orchestrator: A low-cost solution to reduce voltage emergencies for multi-threaded applications

Abstract

Voltage emergencies have become a major challenge to multi-core processors because core-to-core resonance may put all cores into danger which jeopardizes system reliability. We observed that the applications following SPMD (Single Program and Multiple Data) programming model tend to spark domain-wide voltage resonance because multiple threads sharing the same function body exhibit similar power activity. When threads are judiciously relocated among the cores, the voltage droops can be greatly reduced. We propose “Orchestrator”, a sensor-free non-intrusive scheme for multi-core architectures to smooth the voltage droops. Orchestrator focuses on the inter-core voltage interactions, and maximally leverages the thread diversity to avoid voltage droops synergy among cores. Experimental results show that Orchestrator can reduce up to 64% voltage emergencies on average, meanwhile improving performance.