DEAM: Decoupled, Expressive, Area-Efficient Metadata Cache

作     者：刘鹏 方磊 黄巍 Peng Liu;Lei Fang;Michael C.Huang

作者机构：CCF IEEE Department of Information Science and Electronic Engineering Zhejiang University State Key Laboratory of Mathematical Engineering and Advanced Computing ACM Department of Electrical and Computer Engineering University of Rochester NY 14627-0231 U.S.A. 

出 版 物：《Journal of Computer Science & Technology》 (计算机科学技术学报（英文版）)

年 卷 期：2014年第29卷第4期

页      面：679-691页

核心收录：

学科分类：0808[工学-电气工程] 08[工学] 0835[工学-软件工程] 0701[理学-数学] 0811[工学-控制科学与工程] 081201[工学-计算机系统结构] 0812[工学-计算机科学与技术（可授工学、理学学位）] 

基　　金：supported by the Joint Research Fund for Overseas Chinese Scholars and Scholars in Hong Kong and Macao of the National Natural Science Foundation of China under Grant No.61028004 the Open Project Program of the State Key Laboratory of Mathematical Engineering and Advanced Computing under Grant No.2014A08 

主　　题：cache directory multiprocessor 

摘      要：Chip multiprocessor presents brand new opportunities for holistic on-chip data and coherence management solutions. An intelligent protocol should be adaptive to the fine-grain accessing behavior. And in terms of storage of metadata, the size of conventional directory grows as the square of the number of processors, making it very expensive in large-scale systems. In this paper, we propose a metadata cache framework to achieve three goals： 1） reducing the latency of data access and coherence activities, 2） saving the storage of metadata, and 3） providing support for other optimization techniques. The metm：lata is implemented with compact structures and tracks the dynamically changing access pattern. The pattern information is used to guide the delegation and replication of decoupled data and metadata to allow fast access. We also use our metadata cache as a building block to enhance stream prefetching. Using detailed execution-driven simulation, we demonstrate that our protocol achieves an average speedup of 1.12X compared with a shared cache protocol with 1/5 of the storage of metadata.