Thread criticality support in on-chip networks

Abstract

Multicore computing is becoming the mainstream approach in computer system designs to effectively use growing transistor budgets for harnessing performance and energy-efficiency. Increasing the parallelism with more cores requires careful management, allocation, or partitioning of shared resources to cope with varying resource demands from running threads. Predicting critical (or slowest) threads and accelerating execution of those threads can reduce execution time of parallel applications by balancing the execution of threads to synchronization points. The on-chip network is an increasingly important component that services communication of threads running on cores. As the communication latency of threads affects thread criticality, it should be considered and optimized. In this work, we explore thread criticality support in on-chip networks. We propose a flow control technique that reserves router resources to accelerate communication from critical threads. Furthermore, we present thread criticality support in arbiter designs. Our evaluation shows that implementing criticality awareness in an on-chip interconnect design reduces execution time by 22% and increases system throughput by 18% for a 64-core processor.