Improving and Estimating the Precision of Bounds on the Worst-Case Latency of Task Chains

Abstract : One major issue that hinders the use of performance analysis in industrial design processes is the pessimism inherent to any analysis technique that applies to realistic system models. Indeed, such analyses may conservatively declare unschedulable systems that will in fact never miss any deadlines. We advocate the need to compute not only tight upper bounds on worst-case behaviors, but also tight lower bounds. As a first step, we focus on uniprocessor systems executing a set of sporadic or periodic hard real-time task chains. Each task has its own priority, and the chains are scheduled according to the fixed-priority preemptive scheduling policy. Computing the worst-case end-to-end latency (WCEL) of each chain is complex because of the intricate relationship between the task priorities. Compared to the state of the art, our analysis provides upper bounds on the WCEL in the more general case of asynchro-nous task chains, and also provides lower bounds on the WCEL both for synchronous and asynchronous chains. Our computed lower bounds correspond to actual system executions exhibiting a behavior that is as close to the worst case as possible, while all other approaches rely on simulations. Extensive experiments show the relevance of lower bounds on the worst-case behavior for the industrial design of real-time embedded systems. CCS CONCEPTS • Computer systems organization → Embedded systems; KEYWORDS Worst-case end to end latency, Latency analysis, Task chains ACM Reference format:
Type de document :
Article dans une revue
IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems, IEEE, 2018, 37 (11), pp.2578-2589. 〈10.1109/TCAD.2018.2861016〉
Liste complète des métadonnées

https://hal.inria.fr/hal-01956931
Contributeur : Sophie Quinton <>
Soumis le : mardi 18 décembre 2018 - 14:50:16
Dernière modification le : jeudi 17 janvier 2019 - 10:41:45

Fichier

emsoft18-camera_ready.pdf
Fichiers produits par l'(les) auteur(s)

Identifiants

Collections

Citation

Alain Girault, Christophe Prévot, Sophie Quinton, Rafik Henia, Nicolas Sordon. Improving and Estimating the Precision of Bounds on the Worst-Case Latency of Task Chains. IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems, IEEE, 2018, 37 (11), pp.2578-2589. 〈10.1109/TCAD.2018.2861016〉. 〈hal-01956931〉

Partager

Métriques

Consultations de la notice

22

Téléchargements de fichiers

52