Mixed-Criticality Scheduling with I/O

Abstract

This paper addresses the problem of scheduling tasks with differentcriticality levels in the presence of I/O requests. In mixed-criticalityscheduling, higher criticality tasks are given precedence over those of lowercriticality when it is impossible to guarantee the schedulability of alltasks. While mixed-criticality scheduling has gained attention in recentyears, most approaches typically assume a periodic task model. Thisassumption does not always hold in practice, especially for real-time andembedded systems that perform I/O. In prior work, we developed ascheduling technique in the Quest real-time operating system, which integratesthe time-budgeted management of I/O operations with Sporadic Server schedulingof tasks. This paper extends our previous scheduling approach with support formixed-criticality tasks and I/O requests on the same processing core. Resultsshow that in a real implementation the mixed-criticality scheduling methodintroduced in this paper outperforms a scheduling approach consisting of onlySporadic Servers.