Compensating Adaptive Mixed Criticality Scheduling

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


The majority of prior academic research into mixed criticality systems assumes that if high-criticality tasks continue to execute beyond the execution time limits at which they would normally finish, then further workload due to low-criticality tasks may be dropped in order to ensure that the high-criticality tasks can still meet their deadlines. Industry, however, takes a different view of the importance of low-criticality tasks, with many practical systems unable to tolerate the abandonment of such tasks. In this paper, we address the challenge of supporting genuinely graceful degradation in mixed criticality systems, thus avoiding the abandonment problem. We explore the Compensating Adaptive Mixed Criticality (C-AMC) scheduling scheme. C-AMC ensures that both high- and low-criticality tasks meet their deadlines in both normal and degraded modes. Under C-AMC, jobs of low-criticality tasks, released in degraded mode, execute imprecise versions that provide essential functionality and outputs of sufficient quality, while also reducing the overall workload. This compensates, at least in part, for the overload due to the abnormal behavior of high-criticality tasks. C-AMC is based on fixed-priority preemptive scheduling and hence provides a viable migration path along which industry can make an evolutionary transition from current practice.

Original languageEnglish
Title of host publicationRTNS 2022 - Proceedings of the 30th International Conference on Real-Time Networks and Systems
EditorsYasmina Abdeddaïm, Liliana Cucu-Grosjean, Geoffrey Nelissen, Laurent Pautet
Number of pages13
ISBN (Electronic)9781450396509
ISBN (Print)9781450396509
Publication statusPublished - 7 Jun 2022
Event30th International Conference on Real-Time Networks and Systems, RTNS 2022 - Virtual, Online, France
Duration: 7 Jun 20228 Jun 2022

Publication series

NameACM International Conference Proceeding Series


Conference30th International Conference on Real-Time Networks and Systems, RTNS 2022
CityVirtual, Online

Bibliographical note

© 2022 Association for Computing Machinery. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details


  • Real-Time
  • Schedulability Analysis
  • Fixed Priority
  • Mixed Criticality

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