Response time analysis of multiframe mixed-criticality systems with arbitrary deadlines

Hussain, Ishfaq; Awan, Muhammad Ali; Souto, Pedro; Bletsas, Konstantinos; Akesson, Benny; Tovar, Eduardo

http://hdl.handle.net/10400.22/16479

Use this identifier to reference this record.

Name:	Description:	Size:	Format:
ART_CISTER_Hussain_2020.pdf		2.47 MB	Adobe PDF	Download

Send Feedback

Authors

Hussain, Ishfaq

Awan, Muhammad Ali

Souto, Pedro

Bletsas, Konstantinos

Akesson, Benny

Tovar, Eduardo

Abstract(s)

The well-known model of Vestal aims to avoid excessive pessimism in the quantifcation of the processing requirements of mixed-criticality systems, while still guaranteeing the timeliness of higher-criticality functions. This can bring important savings in system costs, and indirectly help meet size, weight and power constraints. This efciency is promoted via the use of multiple worst-case execution time (WCET) estimates for the same task, with each such estimate characterized by a confdence associated with a diferent criticality level. However, even this approach can be very pessimistic when the WCET of successive instances of the same task can vary greatly according to a known pattern, as in MP3 and MPEG codecs or the processing of ADVB video streams. In this paper, we present a schedulability analysis for the new multiframe mixed-criticality model, which allows tasks to have multiple, periodically repeating, WCETs in the same mode of operation. Our work extends both the analysis techniques for Static Mixed-Criticality scheduling (SMC) and Adaptive Mixed-Criticality scheduling (AMC), on one hand, and the schedulability analysis for multiframe task systems on the other. A constrained-deadline model is initially targeted, and then extended to the more general, but also more complex, arbitrary-deadline scenario. The corresponding optimal priority assignment for our schedulability analysis is also identifed. Our proposed worst-case response time (WCRT) analysis for multiframe mixed-criticality systems is considerably less pessimistic than applying the static and adaptive mixed-criticality scheduling tests oblivious to the WCET variation patterns. Experimental evaluation with synthetic task sets demonstrates up to 20% and 31.4% higher scheduling success ratio (in absolute terms) for constrained-deadline analyses and arbitrary-deadline analyses, respectively, when compared to the best of their corresponding frame-oblivious tests.