Suppose that you have the following jobs to schedule in a single-processor operating system.
| Arrival Time | Length | |
|---|---|---|
| Job A | 0 | 10 |
| Job B | 5 | 20 |
| Job C | 8 | 5 |
| Job D | 12 | 3 |
| Job E | 20 | 2 |
| Job F | 26 | 8 |
Question 1 : For the First Come First Served (FCFS) (non-preemptive) scheduling algorithm, show the following:
You may assume that each context switch takes one time unit, and that ties are broken in favor of the job that arrived earlier.
Question 2 : Repeat for the Shortest Job First (SJF) (non-preemptive) scheduling algorithm.
Question 3 : Repeat for the Shortest Completion Time First (SCTF) (preemptive) scheduling algorithm.
Suppose that you have a single processor multi-level-feedback-queue as described in Chapters 8.1 and 8.2. (Do not add the later extra rules.) There are three queues with scheduling quanta of 5, 10, and 20 time units. Each context switch takes one time unit. (This includes when a single job changes queues but continues to execute.) Ties are broken in favor of the job that arrived earlier.
Consider the following three jobs:
Question 4: Carefully diagram how the basic MLFQ scheduler would schedule these jobs until all are complete, including the times of each significant event in the schedule.
These problems involve working out a number of diagrams, so we suggest that you sketch your answers carefully on paper, and then submit by uploading photos to Canvas.