KNOWLEDGE IS POWER: OPERATING SYSTE-CS9252 PREVIOUS YEAR QUESTION PAPER

OPERATING SYSTEM PREVIOUS YEAR QUESTION PAPER,CS9252 PREVIOUS YEAR QUESTION PAPER,PREVIOUS YEAR QUESTION PAPER FOR OPERATING SYSTE,

OPERATING SYSTEM 2006 - B.E CSE

-----------------------------------------------------------------------------------------------------------------------------------
PART-A 10x2 = 20 marks

1. Mention any two essential properties of real time systems.

2. Processes call the operating system with system call interrupt instructions. Why can’t processes make ordinary procedure calls to the operating systems?

3. What is meant by the context of a process?

4. Mention the methods for deadlock recovery in a system.

5. Consider the following set of processes, with the length of the CPU-burst time and the arrival time given in milliseconds:

Process Arrival Time Burst Time

______ ___________ __________

P1 0 75

P2 10 40

P3 10 25

P4 80 20

P5 85 45

a. Draw a Gantt chart illustrating the execution of these processes using preemptive SJF scheduling algorithm.

6. What is the relationship between program locality and TLB hit rate?

7. What is Belady’s anomaly?

8. What is thrashing?

9. Mention the advantages and disadvantages of continuous allocation of files.

10. List the main components of a Linux system.

PART-B 5x16 = 80 marks

11. (i) Explain the MS-DOS system structure with a neat diagram. (8)

(ii) Write notes on Hardware protection. (8)

12. (a) (i)Describe the actions taken by a kernel to context switch between kernel-level threads. (4)

(ii) Consider the following snapshot of a system:

Allocation Max Available

__________ ____ ________

A B C D A B C D A B C D

P0 0 0 1 2 0 0 1 2 1 5 2 0

P1 1 0 0 0 1 7 5 0

P2 1 3 5 4 2 3 5 6

P3 0 6 3 2 0 6 5 2

P4 0 0 1 4 0 6 5 6

Answer the following questions using the banker’s algorithm.

a. What is the content of matrix Need? (2)

b. Is the system in a safe state? If yes, give the safe sequence. (2)

c. If a request from process P1 arrives for (0,4,2,0) can the request be granted immediately? (4)

(iii)Distinguish between short term, long term and medium term scheduling.(4)

OR

b) (i) How does a semaphore solve the critical section problem? Discuss whether semaphores satisfy the three requirements for a solution to the critical section problem. (8)

(ii) A barbershop consists of a waiting room with n chairs and the barber room containing the barber chair. If there are no customers to be served, the barber goes to sleep. If a customer enters the barbershop and all chairs are occupied, then the customer leaves the shop. If the barber is busy but chairs are available, then the customer sits in one of the free chairs. If the barber is asleep, the customer wakes up the barber. Write a program to coordinate the barber and the customers. (8)

13. a. (i) Given memory partitions of 100K, 500 K, 200 K, and 600K (in order), how would each of the First-fit, 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? (8)

(ii) Write down the different issues in real time scheduling. (8)

OR

b. (i)Explain segmentation with a neat diagram. (8)

(ii) Consider a variation of round-robin we will call progressive round-robin. In progressive round-robin, each process has its own time quantum. This starts out at 50 ms, and increases by 50 ms each time it goes through the round-robin queue. Give the advantages and disadvantages of this variant over ordinary round-robin. (8)

14. a. What is the cause of thrashing? Explain the methods by which thrashing could be controlled. (16)

OR

b. Describe different schemes for defining the logical structure of a directory. (16)

15. a. Discuss on the following disk scheduling algorithms:

Shortest Seek Time First, First Come First Served, SCAN, C- LOOK.

(16)

OR

b. Explain briefly how process management is done in Linux. (16)
------------------------------------------------------------------------------------------------------------------------------------

OPERATING SYSTEM 2007-B.E

PART-A
1) Specify the critical factor to be strictly followed in real time system.
2) List out the three main advantages of multiprocessor system.
3) What is co-operating process?
4) What is bounded waiting in critical section?
5) What are the four necessary conditions a system should possess in order to be termed as deadlock?
6) What is segmentation?
7) Why should we use virtual memory?
8) What is meant by thrashing?
9) Name the entries that make up a File Control Block (FCB)?
10) State any two distinguishing features of UUNIX and Windows.

PART-B
11) a) i) Explain the facilities provided by the following operating systems
(1) Clustered system and
(2) Real time system.
ii) List out the services provided by the operating system to programs and to the
users of program.
(or)
b) i) Explain the process creation and process termination on process.
ii) Write short notes on co-operating processes and schedulers.
12) a) Describe the following scheduling algorithms
(i) Shortest job first scheduling
(ii) Round robin scheduling
(iii) Real time scheduling
(iv) Priority scheduling.
(or)
b) What is the important feature of critical section? State the dining philosophers
problem and show how to allocate the several resources among several
processes in a deadlock and starvation free manner.

13) a) i) How can deadlock be detected? Explain.
ii) Write short notes on swapping.
(or)
b) Discuss the advantages of paging memory management and the conversion of
logical address into physical address with necessary hardware.
14) a) Discuss the following page replacement algorithms, giving a suitable page
reference string (i) LRU (ii) FIFO (iii) Optimal.
(or)
b) i) State the various attributes of a file and their purpose.Discuss the various file.
operation
ii) Discuss about demand paging.
15) a) Describe in detail any three methods of implementing the file system.
(or)
b) write short notes on:
(i) Disk structure
(ii) Indexed allocation
(iii) Shortest Seek Time First (SSTF) scheduling.
------------------------------------------------------------------------------------------------------------------------------------

OPERATING SYSTEM-MC1655 NOV/DEC 2007

------------------------------------------------------------------------------------------------------------------------------------

OPERATING SYSTEM-CS1252 NOV/DEC 2009

----------------------------------------------------------------------------------------------------------------------------------------
OPERATING SYSTEM-MC1655 MAY/JUN 2009