Lecture 06: Priority Scheduling and Multilevel Queues

1. Priority Scheduling (Prioritizing critical tasks)
2. Starvation & Aging (The challenge of fairness)
3. Multilevel Queue Scheduling (Organizing diverse workloads)
4. Real-World Architectures (How OSes actually do it)
5. Summary & Discussion

Slide Deck

Key Takeaways

• Priority Scheduling offers fine-grained control over CPU allocation, but its inherent risk is starvation for lower-priority tasks.
• Aging is a crucial mechanism to prevent starvation by dynamically increasing the priority of waiting processes.
• Multilevel Queue Scheduling organizes processes into different classes, allowing for specialized scheduling strategies per class, enhancing system efficiency.
• Modern OS schedulers (e.g., Linux CFS, Windows) are complex, hybrid systems that combine elements of priority, time-sharing, and feedback mechanisms to optimize for various goals like fairness, responsiveness, and throughput.