AnTi-MiCS: Analytical Framework for Bounding Time in Embedded Mixed-Criticality Systems

2026-04-30

AI Summary

In mixed-criticality embedded systems, determining appropriate low worst-case execution times (low WCETs) for low-criticality tasks to balance processor utilization and quality of service (QoS) remains a significant challenge. This work proposes the AnTi-MiCS framework, which employs static design-time analysis to derive a single low WCET per task. Building upon this, the paper further introduces MulTi-MiCS, the first approach to incorporate inter-input temporal correlations to generate multiple low WCETs for each low-criticality task. Both methods substantially enhance resource efficiency while preserving QoS guarantees. Experimental results demonstrate that AnTi-MiCS improves average QoS by 30.27% and reduces utilization waste by 35.89% compared to state-of-the-art techniques; MulTi-MiCS yields additional gains, further improving QoS by 6.41% and reducing waste by 8.23%.

Abstract

In Mixed-Criticality (MC) systems, although the high Worst-Case Execution Time (WCET) serves as a conservative upper bound representing the task's maximum execution time under all conditions, obtaining a low WCET is essential for representing realistic executions and improving utilization and Quality-of-Service (QoS). Nevertheless, determining appropriate low WCET(s) for lower-criticality (LO) modes poses a significant challenge. Opting for a very low value of this WCET enhances processor utilization by scheduling more tasks in LO mode. Conversely, employing a larger WCET ensures fewer mode switches, thereby enhancing QoS, albeit at the cost of processor utilization. This paper proposes an analytical approach, AnTi-MiCS, to determine the appropriate low WCET through design-time analysis of task executions. In some cases, a single low WCET may not be adequate to capture large variations in the execution time distribution, for example, in scenarios like bimodal distributions. Therefore, we further propose a scalable approach, MulTi-MiCS, to compute multiple appropriate low WCETs. This approach exploits the temporal correlation between subsequent inputs presented to the application. Experimental results, conducted on a real platform with embedded real-time benchmarks, demonstrate the efficacy of our proposed scheme, in which QoS is improved by 30.27% on average while reducing utilization waste by 35.89%, compared to existing approaches. Besides, MulTi-MiCS improves QoS by 6.41% compared to AnTi-MiCS while reducing utilization waste by 8.23%.

Problem

• Mixed-Criticality
• WCET
• Quality-of-Service
• Utilization
• Real-Time Systems

Innovation

• Mixed-Criticality Systems
• Worst-Case Execution Time (WCET)
• Quality-of-Service (QoS)
• Temporal Correlation
• Design-Time Analysis