Back to course 'CS401: Operating Systems'

Topic outline

  • Unit 4: CPU Scheduling

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    Central Process Unit (CPU) scheduling deals with having more processes/threads than processors to handles those tasks, meaning how the CPU determines which jobs it is going to handle in what order. A good understanding of how a CPU scheduling algorithm works is essential to understanding how an Operating System works; a good algorithm will optimally allocate resources, allowing an efficient execution of all running programs. A poor algorithm, however, could result in any number of issues, from process being "starved out" to inefficient executing, resulting in poor computer performance. In this unit, we will first discuss the CPU problem statement and the goals of a good scheduling algorithm. Then, we will move on to learning about types of CPU scheduling, such as preemptive and non-preemptive. Finally, we will conclude the module with a discussion on some of the more common algorithms found in UNIX-based Operating Systems.

    Completing this unit should take you approximately 11 hours.

    • Upon successful completion of this unit, you will be able to:

      • discuss CPU scheduling and its relevance to operating systems;
      • explain the general goals of CPU scheduling;
      • describe the differences between preemptive and non-preemptive scheduling; and
      • discuss four CPU scheduling algorithms.

    • 4.1: Scheduling General Objective

      • page icon
        Thread Scheduling Page
        Students must
        Mark as done

        Watch the first lecture from 54:30 to the end, and watch the second lecture until 31:00.

      • url icon
        CPU Scheduling URL
        Students must
        Mark as done

        Read this document.

    • 4.2: Goals

    • 4.3: Types

    • 4.4: Algorithms

    • Unit 4 Exercises and Assessment

      • url icon
        CPU Scheduling Simulation Exercises URL
        Students must
        Mark as done

        Complete both parts of the CPU scheduling simulations. You will need to have Java Installed on your computer. Follow all of the instructions provided. Your results should match the answers provided in the answer keys for Part 1 and Part 2.

      • quiz icon
        Unit 4 Assessment Quiz
        Students must
        Receive a grade

        Review the material on CPU scheduling algorithms. Complete both problems. It might be best to draw out Gantt charts to represent the processes.

        • This assessment does not count towards your grade. It is just for practice!
        • You will see the correct answers when you submit your answers. Use this to help you study for the final exam!
        • You can take this assessment as many times as you want, whenever you want.