Dynamic Data Prefetching in Home-Based Software DSMs  

作　　者：胡伟武 张福新 刘海明 

出　　处：《Journal of Computer Science & Technology》2001年第3期231-241,共11页计算机科学技术学报（英文版）

基　　金：the National Natural Science Foundation of China (No.60073018).

摘　　要：A major overhead in software DSM (Distributed Shared Memory) is the cost of remote memory accesses necessitated by the protocol as well as induced by false sharing. This paper introduces a dynamic prefetching method implemented in the JIAJIA software DSM to reduce system overhead caused by remote accesses. The prefetching method records the interleaving string of INV (invalidation) and GETP (getting a remote page) operations for each cached page and analyzes the periodicity of the string when a page is invalidated on a lock or barrier. A prefetching request is issued after the lock or barrier if the periodicity analysis indicates that GETP will be the next operation in the string. Multiple prefetching requests are merged into the same message if they are to the same host. Performance evaluation with eight well-accepted benchmarks in a cluster of sixteen PowerPC workstations shows that the prefetching scheme can significantly reduce the page fault overhead and as a result achieves a performance increase of 15%-20% in three benchmarks and around 8%-10% in another three. The average extra traffic caused by useless prefetches is only 7%-13% in the evaluation.A major overhead in software DSM (Distributed Shared Memory) is the cost of remote memory accesses necessitated by the protocol as well as induced by false sharing. This paper introduces a dynamic prefetching method implemented in the JIAJIA software DSM to reduce system overhead caused by remote accesses. The prefetching method records the interleaving string of INV (invalidation) and GETP (getting a remote page) operations for each cached page and analyzes the periodicity of the string when a page is invalidated on a lock or barrier. A prefetching request is issued after the lock or barrier if the periodicity analysis indicates that GETP will be the next operation in the string. Multiple prefetching requests are merged into the same message if they are to the same host. Performance evaluation with eight well-accepted benchmarks in a cluster of sixteen PowerPC workstations shows that the prefetching scheme can significantly reduce the page fault overhead and as a result achieves a performance increase of 15%-20% in three benchmarks and around 8%-10% in another three. The average extra traffic caused by useless prefetches is only 7%-13% in the evaluation.

关 键 词：software DSM remote access PREFETCHING performance evaluation 

分 类 号：TP311[自动化与计算机技术—计算机软件与理论]