PACMan: Prefetch-aware cache management for high performance caching

Carole Jean Wu, Aamer Jaleel, Margaret Rose Martonosi, Simon C. Steely, Joel Emer

Research output: Chapter in Book/Report/Conference proceedingConference contribution

89 Scopus citations


Hardware prefetching and last-level cache (LLC) management are two independent mechanisms to mitigate the growing latency to memory. However, the interaction between LLC management and hardware prefetching has received very little attention. This paper characterizes the performance of state-of-the-art LLC management policies in the presence and absence of hardware prefetching. Although prefetching improves performance by fetching useful data in advance, it can interact with LLC management policies to introduce application performance variability. This variability stems from the fact that current replacement policies treat prefetch and demand requests identically. In order to provide better and more predictable performance, we propose Prefetch-Aware Cache Management (PACMan). PACMan dynamically estimates and mitigates the degree of prefetch-induced cache interference by modifying the cache insertion and hit promotion policies to treat demand and prefetch requests differently. Across a variety of emerging workloads, we show that PACMan eliminates the performance variability in state-of-the-art replacement policies under the influence of prefetching. In fact, PACMan improves performance consistently across multimedia, games, server, and SPEC CPU2006 workloads by an average of 21.9% over the baseline LRU policy. For multiprogrammed workloads, on a 4-core CMP, PACMan improves performance by 21.5% on average.

Original languageEnglish (US)
Title of host publicationMICRO 44 - Proceedings of the 44th Annual IEEE/ACM Symposium on Microarchitecture
Number of pages12
StatePublished - 2011
Event44th Annual IEEE/ACM Symposium on Microarchitecture, MICRO 44 - Porto Alegre, RS, Brazil
Duration: Dec 4 2011Dec 7 2011

Publication series

NameProceedings of the Annual International Symposium on Microarchitecture, MICRO
ISSN (Print)1072-4451


Other44th Annual IEEE/ACM Symposium on Microarchitecture, MICRO 44
CityPorto Alegre, RS

All Science Journal Classification (ASJC) codes

  • Hardware and Architecture


  • prefetch-aware replacement
  • reuse distance prediction
  • set dueling
  • shared cache


Dive into the research topics of 'PACMan: Prefetch-aware cache management for high performance caching'. Together they form a unique fingerprint.

Cite this