Semi-partitioned Model for Dual-core Mixed Criticality System

Many Mixed Criticality Algorithms have been developed with an assumption that lower criticality level tasks may be abandoned to guarantee the schedulability of higher criticality tasks when the criticality level of the system changes. But it is valuable to explore a way that all of the tasks remain schedulable throughout the criticality level changes. This paper introduces a possible semi-partitioned model which allows all of the tasks to remain schedulable if only one core increases its criticality level. In such a model, some lower criticality tasks are allowed to migrate instead of being abandoned and detailed response time analysis of the model is given. This paper also addresses possible task allocation approaches, priority assignment and choice of migration tasks. An evaluation is made upon different semi-partitioned approaches and recommendations are given.