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I am trying to understand the difference between these two scheduling techniques. Everything is okay until I found an example where the deadline and the period are equal.

Example

What is the difference between the two techniques if A has the highest priority and C has the lowest one?

lucidbrot
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Pryda
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1 Answers1

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Rate Monotonic Scheduling (RMS) is a real time preemptive scheduling algorithm. It is used for processes which meet the following conditions:

1) Processes should be periodic and there should be a time period for every process;

2) Every process must require the same amount of CPU time on each burst;

3) Every process should be independent;

4) If a process is not periodic, then it should not have a deadline.

Earliest Deadline First (EDF) Scheduling is a type of real time scheduling algorithm. In the EDF, the first two conditions of the RMS algorithm are not required. In EDF, processes are sorted by using their deadlines. A process which has the earliest deadline is run first. If a new process is ready, its deadline is checked. If the deadline is before the running process, then the new process pre-empts the running process.

Massimiliano Kraus
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Subrata K Paul
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  • Does this mean that if all the 4 conditions were satisfied, then the algorithms and implementations would be exactly the same for EDF and RMS? – Mo Kanj Apr 26 '22 at 13:24