Global Real-Time Memory-Centric Scheduling for Multicore Systems

Gang Yao, Rodolfo Pellizzoni, Stanley Bak, Heechul Yun, Marco Caccamo

Research output: Contribution to journalArticlepeer-review

Abstract

As the number of cores increases, more master components can simultaneously access main memory. In real-time systems, this ongoing trend is leading to crippling pessimism when computing the worst-case cache miss time, since a memory request could potentially contend with other requests coming from every other core in the system. CPU-centric scheduling policies, therefore, are no longer sufficient to guarantee schedulability without introducing unacceptable pessimism for memory-intensive task sets. For this reason, we believe a shift is needed towards real-time scheduling approaches that can prevent timing interference from memory contention, while still making efficient use of the multicore platform. Previously, we have demonstrated the practicality of the PREM task model, where each job consists of a sequence of phases, some of which access memory and some of which perform only computation on cached data. In this work, we present the first global memory-centric scheduling policy for memory-intensive task sets whose jobs can be modeled as a sequence of memory-intensive (memory phase) and execution-intensive (execution phase) phases. The proposed policy is parameterizable based on the number of cores which are allowed to concurrently access main memory without saturating it. Building upon results from multicore response-time analysis, we introduce the notion of virtual memory cores as a fundamental technique for performing phase-based response time analysis for memory-intensive task sets. Finally, we use synthetic task set generation to demonstrate that proposed scheduling policy and related schedulability bound do indeed better schedule memory-intensive task sets when compared to state-of-art multicore scheduling.

Original languageEnglish (US)
Article number7328709
Pages (from-to)2739-2751
Number of pages13
JournalIEEE Transactions on Computers
Volume65
Issue number9
DOIs
StatePublished - Sep 1 2016

Keywords

  • Real-time system
  • global multicore schedulability analysis
  • memory centric scheduling

ASJC Scopus subject areas

  • Software
  • Theoretical Computer Science
  • Hardware and Architecture
  • Computational Theory and Mathematics

Fingerprint

Dive into the research topics of 'Global Real-Time Memory-Centric Scheduling for Multicore Systems'. Together they form a unique fingerprint.

Cite this