Anna University Coimbatore 2010-4th Sem B.E Computer Science and Engineering ./B.Tech /e Operating systems - Question Paper

ANNA UNIVERSITY COIMBATORE
B.E/B.TECH DEGREE EXAMINATIONS: MAY/JUNE 2010
REGULATIONS: 2008
4th SEMESTER
080250012- OPERATING SYSTEMS(COMMON TO CSE/IT)

PART-A
ans ALL ques.
1. Differentiate the symmetric and asymmetric multiprocessing systems.
2. Mention the advantages for an operating system designer in using virtual machine architectures.
3. What is meant by situation switch in a processing environment?
4. How to perform threads cancellation in various scenarios.
5. calculate avg. waiting time and turnaround time based on shortest job 1st scheduling algorithm.
PROCESS P1 P2 P3 P4
BURST TIME six five three 1
6. What is meant by Spinlock and why it is useful in multiprocessor systems?
7. When a cycle in resource allocation graph is both a necessary and sufficient condition for deadlocks.
8. Mention the problems that have to be addressed when doing resource preemption to eliminate deadlocks.
9. provided memory partitions of 100KB, 500Kb, 200KB, 300KB, 600Kb(in order), how would firstfit and best fit place processes of 212kb, 417kb, 112kb, 426kb in order.
10. What is meant by copy on write in demand paging?
11. Why thrashing occurs in the system and how it can be handled.
12. Write the characteristics of inverted page table.
13. elaborate the limitations of single level directory?
14. Why must the bit map fro file allocation be kept on mass storage, rather than in main memory?
15. How hash table are used in implementing the directories.
16. Mention the common attributes that are associated with a file.
17. List the advantages of using Streams in UNIX system.
18. elaborate the factors to be considered when selecting a RAID level?
19. What is meant by Sedtor sparing in disk management.
20. Specify the registers that are associated with an I/O port.

PART-B
ans ANY five ques.

21.a) discuss the features and implementation of Interprocess communication system.(6)
b) explain the use of scheduling queues and schedulers in performing process scheduling.

22.a) Consider the subsequent Processes, Burst time, Arrival time.
Process P1 P2 P3 P4 P5 P6
BURST TIME nine six three four two 1
ARRIVAL TIME 0 0 0 0 four 6
compute the subsequent using FCFS,SJF,SRTF,Round Robin
1. Draw the grantt chart.
2. compute avg. waitng time.
3. compute avg. turnaround time.

b) Show how deadlock occurrence can be prevanted in the system.

23.a) Consider the subsequent process

Allocation MAX AVAILABLE
A B C A B C A B C
P0 one three 0 one five three one four 2
P1 0 two 0 two 2 five
P2 one 0 one two four two
P3 0 one one 0 six 4
P4 0 0 one one four 4
Check whether the above processes are safe or not, If safe, display the safe sequence.

b) What is a page fault? discuss.

24.a) discuss the concept of segmentation with paging and show how it is implemented.
b) explain the basic concepts of demand paging and show the steps in gandling a page fault.

25.a) Write short note on any 2 directory structure.
b) How many page faults occur for the LRU and Optimal algorithm for the subsequent reference string, for 4 page frames? 1,2,3,4,5,3,4,1,6,7,8,7,8,9,7,8,9,5,4,5,4,2.

26. discuss the subsequent file allocation methods:
1. Linked allocation
2. Indexed allocation
3. Contiguous allocation

27.a) Consider the request queue as [98,183,37,122,14,124,65,67]. Currently the Head pointer is at 53. obtain the seek time using SST,SCAN and LOOK schemes.
b) discuss the process of creating partitions and performing mount operation in a file system.

28.a) discuss the FCFS and CSCAN disk scheduling algorithm with suitable examples.
b) explain how semaphores achieve synchronization in readers-writers issue and bounded-buffer issue.

************THE END**************

Earning:   Approval pending.