CS 450: Operating Systems

Lecture 05 reading/review questions:

1. Name and define the essential scheduling metrics.
2. What may "fairness" mean, in the context of scheduling?
3. Give a specific example where enforcing fairness may conflic with other scheduling goals.
4. What is the convoy effect?
5. What are some advantages that non-preemptive schedulers have over preemptive schedulers?
6. What are some advantages that preemptive schedulers have over non-preemptive ones?
7. Explain response time, in your own words.
8. Explain how amortization applies to the selection of a time slice when implementing round-robin.
9. Why is RR a poor scheduling policy for optimizing turnaround time?
10. For what types of workloads and quantum lengths does SJF deliver the same response times as RR?
11. What happens to response time with RR as quantum lengths increase? Can you write an equation that gives the worst-case response time, given N jobs?
12. What are some ways to deal with the problem of the lack of a priori knowledge of job/burst lengths?
13. What scheduling issues does the MLFQ scheduler seek to address?
14. How does the MLQ scheduling approach work?
15. What scheduling issues does a fair-share scheduler seek to address?
16. How does a lottery scheduler work?
17. What is the problem of cache coherence?
18. What are some solutions to the cache coherence problem?