Firmness analysis of real-time applications under static-priority preemptive scheduling

Amirreza Baghbanbehrouzian, Dip Goswami, Twan Basten, Marc Geilen, Seyedhadi Seyedalizadeh Ara, Martijn Hendriks

Research output: Contribution to conferencePaperAcademic

2 Citations (Scopus)


(m, k)-firm real-time tasks must meet the deadline of at least m jobs out of any k consecutive jobs to satisfy the firmness requirement. Scheduling of an (m,k)-firm task requires firmness analysis, whose results are used to provide system-level guarantees on the satisfaction of firmness conditions. We address firmness analysis of an (m, k)-firm task that is intended to be added to a set of asynchronous tasks scheduled under a Static-Priority Preemptive (SPP) policy. One of the main causes of deadline misses in periodic tasks running under an SPP policy is interference from higher priority tasks. Since the synchrony between the newly added task and higher priority tasks is unknown, the interference from the higher priority tasks is also unknown. We propose an analytic Firmness Analysis (FAn) method to obtain a synchrony that results in the maximum minimum number of deadline hit jobs in any k consecutive jobs of the task. Scalability of FAn is compared with that of existing work - a brute-force search approach - and a timed-automata model of the problem that is analysed using the reachability check of the Uppaal model checker. Our method substantially reduces the complexity of the analysis.
Original languageEnglish
Number of pages10
Publication statusPublished - 8 Aug 2018
EventIEEE Real-Time and Embedded Technology and Applications Symposium - Porto, Portugal
Duration: 11 Apr 201813 Apr 2018


ConferenceIEEE Real-Time and Embedded Technology and Applications Symposium
Abbreviated titleRTAS 2018


  • (m,k) firm real time tasks
  • Deadline miss
  • Static priority preemptive


Dive into the research topics of 'Firmness analysis of real-time applications under static-priority preemptive scheduling'. Together they form a unique fingerprint.

Cite this