Enabling Highly Efficient k-Means Computations on the SW26010 Many-Core Processor of Sunway TaihuLight  

作　　者：Min Li Chao Yang Qiao Sun Wen-Jing Ma Wen-Long Cao Yu-Long Ao 

机构地区：[1]Institute of Software,Chinese Academy of Sciences,Beijing 100190,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]School of Mathematical Sciences,Peking University,Beijing 100871,China [4]Center for Data Science,Peking University,Beijing 100871,China [5]peng Cheng Laboratory,Shenzhen 518052,China

出　　处：《Journal of Computer Science & Technology》2019年第1期77-93,共17页计算机科学技术学报（英文版）

基　　金：the National Key Research and Development Plan of China under Grant No.2016YFB0200603;the National Natural Science Foundation of China under Grant No.91530323;the Beijing Natural Science Foundation of China under Grant No.JQ18001.

摘　　要：With the advent of the big data era,the amounts of sampling data and the dimensions of data features are rapidly growing.It is highly desired to enable fast and efficient clustering of unlabeled samples based on feature similarities. As a fundamental primitive for data clustering,the k-means operation is receiving increasingly more attentions today.To achieve high performance k-means computations on modern multi-core/many-core systems,we propose a matrix-based fused framework that can achieve high performance by conducting computations on a distance matrix and at the same time can improve the memory reuse through the fusion of the distance-matrix computation and the nearest centroids reduction.We implement and optimize the parallel k-means algorithm on the SW26010 many-core processor,which is the major horsepower of Sunway TaihuLight.In particular,we design a task mapping strategy for load-balanced task distribution,a data sharing scheme to reduce the memory footprint and a register blocking strategy to increase the data locality.Optimization techniques such as instruction reordering and double buffering are further applied to improve the sustained performance.Discussions on block-size tuning and performance modeling are also presented.We show by experiments on both randomly generated and real-world datasets that our parallel implementation of k-means on SW26010 can sustain a double-precision performance of over 348.1 Gflops,which is 46.9% of the peak performance and 84%of the theoretical performance upper bound on a single core group,and can achieve a nearly ideal scalability to the whole SW26010 processor of four core groups.Performance comparisons with the previous state-of-the-art on both CPU and GPU are also provided to show the superiority of our optimized k-means kernel.

关 键 词：PARALLEL K-MEANS performance optimization SW26010 PROCESSOR Sunway TaihuLight 

分 类 号：TP[自动化与计算机技术]