A Review of Sufficient Schedulability Analysis for Fixed Priority Scheduling Systems

This papercarries out a survey of sufficient schedulability analysis forfixed priority (FP) scheduling. The most common used fixed priority assignment is the rate monotonic (RM) algorithm, according to its policy, the task priorities are ordered based on their activation rates, so that the task with the shortest period is assigned the highest priority. However, when each task’s relative deadline is not equal to its period, the RM algorithm is not suitable to assign the task priorities. When relative deadlines are less than or equal to periods,the deadline monotonic (DM) algorithm can be deployed to schedule the tasks. The utilization based schedulability analysis has the advantage of simple implementation, and manyexisting schedulability analyses on uniprocessor are covered.

Schedulability Analysis of Fixed Priority Servers for Scheduling Aperiodic Real-Time Tasks – A Review

This paper focus on the schedulability analysis of fixed priority servers. A number of fixed priority servers and their schedulability analysis are reviewed, these results and properties can be used for constructing systems with different timing constraints, where real-time tasks with hard deadlines and the soft aperiodic tasks can be scheduled in the same system. The aperiodic tasks in the fixed priority servers are not preemptable, and they are scheduled in a first-come first-served manner. There is only one server with many periodic or sporadic tasks in the system. The tasks and the server are scheduled by a fixed priority algorithm such as rate monotonic or deadline monotonic.