rate-monotonic scheduling

In computer science, rate-monotonic scheduling (RMS) is a priority assignment algorithm used in real-time operating systems (RTOS) with a static-priority scheduling class. The static priorities are assigned according to the cycle duration of the job, so a shorter cycle duration results in a higher job priority. These operating systems are generally preemptive and have deterministic guarantees with regard to response times. Rate monotonic analysis is used in conjunction with those systems to provide scheduling guarantees for a particular application. Introduction A simple version of rate-monotonic analysis assumes that threads have the following properties: No resource sharing (processes do not share resources, e.g. a hardware resource, a queue, or any kind of semaphore blocking or non-blocking (busy-waits)) Deterministic deadlines are exactly equal to periods Static priorities (the task with the highest static priority that is runnable immediately preempts all other tasks) Static priorities assigned according to the rate monotonic conventions (tasks with shorter periods/deadlines are given higher priorities) Context switch times and other thread operations are free and have no impact on the model