No. of Printed Pages: 3 IBICS-OI9I .B.Tech. -VIEP -COMPUTER SCIENCE AND

ENGINEERING (BTCSVI) Term-End Examination 00553 December, 2016
BICS-019 OPERATING SYSTEMS
Time hours Maximum Marks: 70
Note: Question no. 1 is compulsory; Answer any six questions from the rest. All questions carry equal marks.

1. There are four processes P1, P2, P3 and P4. The processing time (CPU time) of each process is given below:

Process Processing Time

P1 15

P2 20

P3 17

P4 10

The arrival time of each process for execution is the same, i.e., zero. Calculate the average waiting time and the turnaround time of the above processes for the following scheduling algorithms: 10

SJF

FCFS

2. Write an algorithm for solving producer and consumer problems with a bounded. buffer and explain the logic of the algorithm. Justify that it will not lead to starvation. 10

3. List and explain the four necessary conditions that must hold simultaneously for a deadlock to occur. Explain the different mechanism to avoid deadlocks. 10

4. Discuss the hardware support for

paging, and

(b)segmentation. 10

5. What are the two widely used methods for allocating disk spaces to files? Discuss the merits and demerits of each method. 10

6. What is the cause of thrashing How does the working set model prevent thrashing? Explain it with the help of an example. 10

7. What are the different file organization methods? Discuss the merits and demerits of any two methods. 6

Explain the structure of an executable file in the Unix operating system. 4

8. What are the tasks performed by the following? 4

"Memory management part of an operating system

Device Driver

Explain the following terms 6

Authentication and Authorization

Race Condition

Process Control Block