Test Papers / Previous Question Papers of IGNOU CS13 Operating Systems January 2001

MCA (III Yr)
Term-End Examination

January, 2001

CS13 : Operating Systems

Time: 3 hours
Maximum Marks: 75

1. (a) Write an algorithm for implementing Dining philosopher problem using semaphores. Also describe the problems and the algorithm in detail.

(b) What is the time stamping scheme of distributed system for mutual exclusion? Explain the functioning of the scheme through a diagram.

(c) Describe the algorithm proposed by Ricart and Agrawal for distributed mutual exclusion. Also distinguish between this algorithm and Lamport;'s algorithm on the following lines:
- Correctness of the algorithm
- Deadlock
- Communication cost

2.Discuss various machine level implementation of mutual exclusion in general. Also discuss suitability and efficiency of these algorithms.

3. (a) Explain the advantages and disadvantages of segmented and paged implementation of virtual memory. Explain through a diagram, the principles of address translation in combined segmentation and paging. What is the drawback of this translation scheme?

(b) Describe Belady's anomalous behaviour of FIFO.

4 (a) What is thrashing? What is the cause of thrashing? How does the system detect thrashing? Once it detects thrashing, what are the techniques tp prevent it?

(b) Discuss the difference between preemptive and nonpreemptive scheduling.

5. (a) Discuss scheduling and interprocessor communication suitable for hypercube multiprocessor operating system .

(b) What is RPC (Remote Procedure Call) ? What are the major issue in implementing the RPC? Describe them briefly.

6. (a) Describe the functioning of DES. What are its advantages and disadvantages>?

(b) Describe deadlock detection and recovery algorithm for centralized operating system.