Rate Monotonic Scheduling

Rate monotonic scheduling (RMS ) is a priority scheduling method for interruptible, periodic jobs. It is widely used in real-time systems. The priorities are statically defined by the period of a job: the shorter the period of a job, the higher its priority.

Aperiodic jobs can be executed within a fictitious periodic jobs, which is also known as server principle.

Schedulability

Under what conditions is a lot of jobs at RMS guaranteed schedulable?

• Sufficient conditions according to Liu and Layland. If the load is less than or equal to a load barrier, job set is schedulable. The barrier is dependent only on the number of jobs:

• Harmonic period durations. If the period lengths are multiples of each other (harmonic ), the jobs are schedulable if. Under this condition, RMS is therefore optimal.