Page 145 - DCAP403_Operating System

Operating System

Notes 9. Given memory partitions of l00K, 500K, 200K, 300K, and 600K (in order), how would each

of the fi rst-fi t, best-fit, and worst-fit algorithms place processes of 212K, 417K, 112K, and

426K (in order)? Which algorithm makes the most efficient use of memory?

10. Why is it that, on a system with paging, a process cannot access memory that it does not
own? How could the operating system allow access to other memory? Why should it or
should it not?
11. What is the cause of thrashing? How does the system detect thrashing? Once it detects
thrashing, what can the system do to eliminate this problem?
12. What is virtual memory? Explain the working of virtual memory.
13. Describe the dynamic page replacement method.

Answers: Self Assessment

1. overlays 2. destination 3. uniprocessor
4. worst fi t 5. swap out 6. mapping
7. perfect prediction 8. Thrashing 9. First-In Not-Used First-Out
10. Erasable Programmable Read Only Memory 11. Random Access Memory
12. 1024 KB

7.17 Further Readings

Books Andrew M. Lister, Fundamentals of Operating Systems, Wiley.
Andrew S. Tanenbaum And Albert S. Woodhull, Systems Design and Implementation,
Prentice Hall.
Andrew S. Tanenbaum, Modern Operating System, Prentice Hall.
Deitel H.M., “Operating Systems, 2nd Edition, Addison Wesley.

Colin Ritchie, Operating Systems, BPB Publications.
I.A. Dhotre, Operating System, Technical Publications.
Milankovic, Operating System, Tata MacGraw Hill, New Delhi.
Silberschatz, Gagne & Galvin, “Operating System Concepts”, John Wiley & Sons,
Seventh Edition.
Stalling, W., “Operating Systems”, 2nd Edition, Prentice Hall.

Online links www.en.wikipedia.org
www.web-source.net
www.webopedia.com

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