Fixed priority scheduling with pre-emption thresholds and cache-related pre-emption delays: integrated analysis and evaluation

Reinder Bril, Sebastian Altmeyer, Martijn van den Heuvel, Robert Ian Davis, Moris Benham

Research output: Contribution to journalArticlepeer-review


Commercial off-the-shelf programmable platforms for real-time systems typically contain a cache to bridge the gap between the processor speed and main memory speed. Because cache-related pre-emption delays (CRPD) can have a significant influence on the computation times of tasks, CRPD have been integrated in the response time analysis for fixed-priority pre-emptive scheduling (FPPS). This paper presents CRPD aware response-time analysis of sporadic tasks with arbitrary deadlines for fixed-priority pre-emption threshold scheduling (FPTS), generalizing earlier work. The analysis is complemented by an optimal (pre-emption) threshold assignment algorithm, assuming the priorities of tasks are given. We further improve upon these results by presenting an algorithm that searches for a layout of tasks in memory that makes a task set schedulable. The paper includes an extensive comparative evaluation of the schedulability ratios of FPPS and FPTS, taking CRPD into account. The practical relevance of our work stems from FPTS support in AUTOSAR, a standardized development model for the automotive industry.
Original languageEnglish
Pages (from-to)1-64
Number of pages64
JournalReal-Time Systems
Publication statusPublished - 31 Jan 2017

Bibliographical note

© The Author(s) 2017


  • real time
  • scheduling
  • fixed priority
  • preemption thressholds
  • CRPD
  • cache related preemption delays

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