Green computing: power optimisation of VFI-based real-time multiprocessor dataflow applications (extended version)

    Research output: Book/ReportReportProfessional

    66 Downloads (Pure)

    Abstract

    Execution time is no longer the only performance metric for computer systems. In fact, a trend is emerging to trade raw performance for energy savings. Techniques like Dynamic Power Management (DPM, switching to low power state) and Dynamic Voltage and Frequency Scaling (DVFS, throttling processor frequency) help modern systems to reduce their power consumption while adhering to performance requirements. To balance flexibility and design complexity, the concept of Voltage and Frequency Islands (VFIs) was recently introduced for power optimisation. It achieves fine-grained system-level power management, by operating all processors in the same VFI at a common frequency/voltage.This paper presents a novel approach to compute a power management strategy combining DPM and DVFS. In our approach, applications (modelled in full synchronous dataflow, SDF) are mapped on heterogeneous multiprocessor platforms (partitioned in voltage and frequency islands). We compute an energy-optimal schedule, meeting minimal throughput requirements. We demonstrate that the combination of DPM and DVFS provides an energy reduction beyond considering DVFS or DMP separately. Moreover, we show that by clustering processors in VFIs, DPM can be combined with any granularity of DVFS. Our approach uses model checking, by encoding the optimisation problem as a query over priced timed automata. The model-checker Uppaal Cora extracts a cost minimal trace, representing a power minimal schedule. We illustrate our approach with several case studies on commercially available hardware.
    Original languageUndefined
    Place of PublicationEnschede
    PublisherCentre for Telematics and Information Technology (CTIT)
    Number of pages32
    Publication statusPublished - 24 Jun 2015

    Publication series

    NameCTIT Technical Report Series
    PublisherUniversity of Twente, Centre for Telematics and Information Technology (CTIT)
    No.TR-CTIT-15-04
    ISSN (Print)1381-3625

    Keywords

    • Throughput
    • Voltage and Frequency Islands
    • IR-96408
    • Transition overheads
    • EC Grant Agreement nr.: FP7/318490
    • Heterogeneous
    • EC Grant Agreement nr.: FP7/2007-2013
    • Data flow
    • Green Computing
    • Dynamic Voltage and Frequency Scaling (DVFS)
    • Dynamic Power Management (DPM)
    • Priced Timed Automata
    • UPPAAL
    • METIS-312652
    • Power Minimisation
    • EWI-26102

    Cite this