Operating System MSc IT term 2nd Past Paper 2016 UOS

University of Sargodha
M. Sc. 2nd Term Exam 2016

Subject: I. T
Paper: Operating Systems (CMP-3611)
Time Allowed: 2:30 Hour
Maximum Marks: 80

Objective Part (Compulsory)

Q1. Write short answers of the following in 2-3 lines each. (16*2)

1. What is a process? What information does an operating system generally need to keep about running processes in order to execute them?
2. What is Symmetric Multiprocessing?
3. Which of the following scheduling algorithms are non preemptive? FIFO, Shortest Job First, Round Robin.
4. What are the advantages of Interprocess communication?
5. Define throughput and response time.
6. What is difference between Process Contention Scope and system Contention Scope?
7. What is meant by Multi-programming?
8. What is Dispatcher?
9. What is Spinlock?
10. What are counting Semaphores?
11. What are different types of Fragmentation?
12. What is Safe State?
13. What is Dynamic Linking?
14. What is Thrashing?
15. What are main advantages of many-to-many model for threads?
16. What will be the problems if wait() primitive is not followed by signal() and vice versa i.e. if wait() primitive is missing before signal()?

Subjective Part (12*4=48)

Note: Attempt any four questions. All questions carry equal marks.

Q2. Compute average turn-around time and average waiting time using FIFO and SJF. [6+6]
Process: P0, P1, P2, P3, P4, P5
Arrival Time: 1, 2, 3, 5, 6, 7
CPU Time: 5, 8, 4, 1, 6, 1

Q3.
a) Write down solution of Dining Philosopher Problem using Semaphores. [6]
b) Write down solution of producer/consumer problem using Semaphores. [6]

Q4. What is deadlock? How deadlock can be prevented?

Q5. a) Explain different Directory Structures?

Q6. a) Draw the diagram of Segmentation hardware. [8]
b) What are the advantages and disadvantages of small page size? [4]

Q7. Find out page faults using Optimal and FIFO algorithm for following string. [6+6]
3, 4, 5, 2, 6, 1, 6, 3, 1, 9, 7, 8, 5, 3
Consider only three free frames are available.