On the Scheduling of Mixed-Criticality Real-Time Task Sets

Abstract—The functional consolidation induced by the costreduction trends in embedded systems can force tasks of different criticality (e.g. ABS Brakes with DVD) to share a processor and interfere with each other. These systems are known as mixedcriticality systems. While traditional temporal isolation techniques prevent all inter-task interference, they waste utilization because they need to reserve for the absolute worst-case execution time (WCET) for all tasks. In many mixed-criticality systems the WCET is not only rare, but at times difficult to calculate, such as the time to localize all possible objects in an obstacle avoidance algorithm. In this situation it is more appropriate to allow the execution time to grow by stealing cycles from lower-criticality tasks. Even more crucial is the fact that temporal isolation techniques can stop a high-criticality task (that was overrunning its nomimal WCET) to allow a low-criticality task to run, making the former miss its deadline. We ...

• Type: Conference
• Year: 2009
• Where: RTSS
• Authors: Dionisio de Niz, Karthik Lakshmanan, Ragunathan Rajkumar
• Keywords: Applied Computing, Criticality Inversion, Criticality Inversion Problem, RTSS 2009, Temporal Isolation Techniques