16. Objectives of Scheduling

Summary

In this video, the lecturer discusses key objectives of scheduling in operating systems, including fairness, throughput, predictability, and resource utilization. The aim is to treat processes equally, maximize system throughput, ensure predictable execution times, and keep system resources busy. The video also touches on the importance of avoiding indefinite postponement and prioritizing higher priority processes. Lastly, it emphasizes that minimizing overhead can significantly improve system performance. The next lecture will cover scheduling criteria and types of scheduling algorithms, inviting viewers to ask any questions in the comments.

Takeaways

• 😀 The lecture discusses the objectives of scheduling in operating systems.
• 😀 Fairness is a key objective, ensuring all processes are treated equally without indefinite postponement.
• 😀 Throughput refers to maximizing the number of processes executed per unit of time, usually measured in milliseconds.
• 😀 Predictability ensures that each process runs in roughly the same amount of time, regardless of system load.
• 😀 Keeping resources busy is crucial, meaning all system resources should be utilized as efficiently as possible.
• 😀 Avoiding indefinite postponement guarantees that no process waits forever to be executed.
• 😀 Scheduling should favor higher-priority processes, executing them before lower-priority ones.
• 😀 Overhead should be managed carefully; investing system resources as overhead should significantly improve overall performance.
• 😀 The lecture emphasizes that multiple objectives must be balanced when designing scheduling algorithms.
• 😀 Future lectures will cover scheduling criteria and types of scheduling in detail.

Q & A

What is the first objective of scheduling discussed in the video?

The first objective is fairness. It suggests that the CPU or the operating system should treat all processes equally during scheduling, ensuring that no process is indefinitely postponed.

What does throughput in scheduling refer to?

Throughput refers to the scheduling algorithm's ability to execute the maximum number of processes per unit of time, generally measured in milliseconds.

What does the 'predictable' objective of scheduling mean?

The 'predictable' objective suggests that processes should run in approximately the same amount of time, regardless of the system load. Higher system loads should not affect the process execution time.

What is meant by the objective 'keep resources busy'?

This objective means that the system should keep its resources, such as CPU and memory, as occupied as possible to maximize efficiency and minimize idle time.

Why is avoiding indefinite postponement important in scheduling?

Avoiding indefinite postponement ensures that no process is left waiting forever for execution, allowing each process to eventually run and complete its task.

How should the system handle processes with different priorities?

If priorities are assigned to processes, the system should favor higher priority processes and execute them before lower priority ones to meet the needs of critical tasks.

What does the 'overhead' objective suggest?

The 'overhead' objective suggests that investing a small portion of system resources as overhead can significantly improve the overall performance of the system.

Can the scheduling algorithm improve system performance by focusing on overhead?

Yes, by dedicating some resources to overhead tasks, the system's performance can improve greatly, as the scheduling algorithm becomes more efficient.

What are the key objectives of scheduling covered in this lecture?

The key objectives include fairness, throughput, predictability, keeping resources busy, avoiding indefinite postponement, favoring higher priority processes, and reducing overhead.

What will be discussed in the next lecture according to the video?

In the next lecture, the discussion will focus on scheduling criteria and the different types of scheduling algorithms.