Exploring Synchronization in Cache Coherent Manycore Systems: A Case Study with Xeon Phi
Xin James He, Zhiwen Chen, Jianhua Sun, Hao Chen, Dong Li, Zhe Quan · 2017
Intel Xeon Phi is a many-core architecture, featuring more than 50 cores and 200 hardware threads. Given this scale and its other distinctive architectural features, highly-concurrent applications on Xeon Phi may behave differently than on tradi- tional multi-core systems. Yet, concurrency issues especially for synchronization intensive applications on this platform have not been thoroughly analyzed. In this paper, we conduct an extensive analysis at multiple layers, from the underlying hardware cache- coherence protocol up to the user-level applications, aiming to present the most exhaustive study of synchronization on Xeon Phi. Through a range of benchmarks, we testify the feasibility and advantage of accelerating concurrent applications with Xeon Phi. Meanwhile, we identify severe scalability issues relevant to synchronization, and solutions to these issues are discussed. We believe this work can be used as guidelines both for designing better synchronization mechanisms and in optimizing concurrent applications in order to fully exploit the capability of Xeon Phi.