Using a user-level memory thread for correlation prefetching
- 1 May 2002
- journal article
- Published by Association for Computing Machinery (ACM) in ACM SIGARCH Computer Architecture News
- Vol. 30 (2), 171-182
- https://doi.org/10.1145/545214.545235
Abstract
This paper introduces the idea of using a User-Level Memory Thread (ULMT) for correlation prefetching. In this approach, a user thread runs on a general-purpose processor in main memory, either in the memory controller chip or in a DRAM chip. The thread performs correlation prefetching in software, sending the prefetched data into the L2 cache of the main processor. This approach requires minimal hardware beyond the memory processor: the correlation table is a software data structure that resides in main memory, while the main processor only needs a few modifications to its L2 cache so that it can accept incoming prefetches. In addition, the approach has wide usability, as it can effectively prefetch even for irregular applications. Finally, it is very flexible, as the prefetching algorithm can be customized by the user on an application basis. Our simulation results show that, through a new design of the correlation table and prefetching algorithm, our scheme delivers good results. Specifically, nine mostly-irregular applications show an average speedup of 1.32. Furthermore, our scheme works well in combination with a conventional processor-side sequential prefetcher, in which case the average speedup increases to 1.46. Finally, by exploiting the customization of the prefetching algorithm, we increase the average speedup to 1.53.Keywords
This publication has 12 references indexed in Scilit:
- Dead-block prediction & dead-block correlating prefetchersPublished by Association for Computing Machinery (ACM) ,2001
- Predictor-directed stream buffersPublished by Association for Computing Machinery (ACM) ,2000
- Push vs. pullPublished by Association for Computing Machinery (ACM) ,2000
- Comparing data forwarding and prefetching for communication-induced misses in shared-memory MPsPublished by Association for Computing Machinery (ACM) ,1998
- Prefetching using Markov predictorsPublished by Association for Computing Machinery (ACM) ,1997
- Scalable processors in the billion-transistor era: IRAMComputer, 1997
- Compiler-based prefetching for recursive data structuresPublished by Association for Computing Machinery (ACM) ,1996
- Reducing memory latency via non-blocking and prefetching cachesPublished by Association for Computing Machinery (ACM) ,1992
- Improving direct-mapped cache performance by the addition of a small fully-associative cache and prefetch buffersPublished by Association for Computing Machinery (ACM) ,1990
- Dynamic Improvement of Locality in Virtual Memory SystemsIEEE Transactions on Software Engineering, 1976