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Modern Computer Architecture and Organization - Third Edition
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Rate monotonic scheduling (RMS) is an algorithm for assigning thread priorities in preemptive, hard, real-time applications where threads execute periodically. RMS assigns the highest priority to the thread with the shortest execution period, the next-highest priority to the thread with the next-shortest execution period, and so on. An RMS system is schedulable, meaning all tasks are guaranteed to meet their deadlines (assuming that no inter-thread interactions or other activities, such as interrupts, cause processing delays) if the following condition is met:

This formula represents the maximum fraction of available processing time that n threads can consume. In this formula, Ck is the maximum execution time required for thread k, and Tk is the execution period of thread k.
Is the following system composed of three threads schedulable?
|
Thread |
Execution time (Ck), ms |
Execution period (Tk), ms |
|---|---|---|
|
Thread 1 |
50 |
100 | ...