2026-08-06T13:54:15Z https://drops.dagstuhl.de/oai

oai:drops-oai.dagstuhl.de:10758 2024-03-06T10:46:37Z ddc:004 open_access

Response-Time Analysis of Limited-Preemptive Parallel DAG Tasks Under Global Scheduling Nasri, Mitra Nelissen, Geoffrey Brandenburg, Björn B. parallel DAG tasks global multiprocessor scheduling schedulability analysis non-preemptive jobs precedence constraints worst-case response time OpenMP Most recurrent real-time applications can be modeled as a set of sequential code segments (or blocks) that must be (repeatedly) executed in a specific order. This paper provides a schedulability analysis for such systems modeled as a set of parallel DAG tasks executed under any limited-preemptive global job-level fixed priority scheduling policy. More precisely, we derive response-time bounds for a set of jobs subject to precedence constraints, release jitter, and execution-time uncertainty, which enables support for a wide variety of parallel, limited-preemptive execution models (e.g., periodic DAG tasks, transactional tasks, generalized multi-frame tasks, etc.). Our analysis explores the space of all possible schedules using a powerful new state abstraction and state-pruning technique. An empirical evaluation shows the analysis to identify between 10 to 90 percentage points more schedulable task sets than the state-of-the-art schedulability test for limited-preemptive sporadic DAG tasks. It scales to systems of up to 64 cores with 20 DAG tasks. Moreover, while our analysis is almost as accurate as the state-of-the-art exact schedulability test based on model checking (for sequential non-preemptive tasks), it is three orders of magnitude faster and hence capable of analyzing task sets with more than 60 tasks on 8 cores in a few seconds. Schloss Dagstuhl – Leibniz-Zentrum für Informatik Mitra Nasri and Geoffrey Nelissen and Björn B. Brandenburg 2019 Is Part Of LIPIcs, Volume 133, 31st Euromicro Conference on Real-Time Systems (ECRTS 2019) InProceedings Text doc-type:ResearchArticle publishedVersion application/pdf doi:10.4230/LIPIcs.ECRTS.2019.21 urn:nbn:de:0030-drops-107587 https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ECRTS.2019.21 eng https://creativecommons.org/licenses/by/3.0/legalcode