PDIP: Priority Directed Instruction Prefetching

Bhargav Reddy Godala, Sankara Prasad Ramesh, Gilles A. Pokam, Jared Stark, Andre Seznec, Dean Tullsen, David I. August

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

Abstract

Modern server workloads have large code footprints which are prone to front-end bottlenecks due to instruction cache capacity misses. Even with the aggressive fetch directed instruction prefetching (FDIP), implemented in modern processors, there are still significant front-end stalls due to I-Cache misses. A major portion of misses that occur on a BPU-predicted path are tolerated by FDIP without causing stalls. Prior work on instruction prefetching, however, has not been designed to work with FDIP processors. Their singular goal is reducing I-Cache misses, whereas FDIP processors are designed to tolerate them. Designing an instruction prefetcher that works in conjunction with FDIP requires identifying the fraction of cache misses that impact front-end performance (that are not fully hidden by FDIP), and only targeting them.In this paper, we propose Priority Directed Instruction Prefetching (PDIP), a novel instruction prefetching technique that complements FDIP by issuing prefetches for only targets where FDIP struggles - along the resteer path of front-end stall-causing events. PDIP identifies these targets and associates them with a trigger for future prefetch. At a 43.5KB budget, PDIP achieves up to 5.1% IPC speedup on important workloads such as cassandra and a geomean IPC speedup of 3.2% across 16 benchmarks.

Original languageEnglish (US)
Title of host publicationSummer Cycle
PublisherAssociation for Computing Machinery
Pages846-861
Number of pages16
ISBN (Electronic)9798400703850
DOIs
StatePublished - Apr 27 2024
Event29th ACM International Conference on Architectural Support for Programming Languages and Operating Systems, ASPLOS 2024 - San Diego, United States
Duration: Apr 27 2024May 1 2024

Publication series

NameInternational Conference on Architectural Support for Programming Languages and Operating Systems - ASPLOS
Volume2

Conference

Conference29th ACM International Conference on Architectural Support for Programming Languages and Operating Systems, ASPLOS 2024
Country/TerritoryUnited States
CitySan Diego
Period4/27/245/1/24

All Science Journal Classification (ASJC) codes

  • Software
  • Information Systems
  • Hardware and Architecture

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