JNTU Kakinada B-Tech 3-1 RT31055 I OPERATING SYSTEMS R13 April 2018 Question Paper

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Code No: RT31055
III B. Tech I Semester Supplementary Examinations, May- 2018
OPERATING SYSTEMS (Common to Computer Science Engineering and Information Technology)Time: 3 hours Max. Marks: 70
Note: 1. Question Paper consists of two parts (Part-A and Part-B) 2. Answering the question in Part-A is compulsory
3. Answer any THREE Questions from Part-B
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PART ?A
1 a) Differentiate between kernel mode and user mode. [3M]
b) Define multi-threading? Explain its benefits. [4M]
c) What is a critical section? Give examples. [4M]
d) What do you mean by page fault? [4M]
e) What are the necessary conditions for deadlock? [4M]
f) Compare bit map based allocation of blocks on the disk with a free block list. [3M]
PART -B
2 a) Explain the purpose of system calls and discuss the system calls related to
process control and communication in brief.
[8M]
b) Explain evolution of operating systems.
[8M]
3 a) Describe the differences among long-term scheduling. short-term, and medium-
term scheduling.
[8M]
b) What are the components of process control block? Explain.
[8M]
4 a) Write Peterson Algorithm for 2-process synchronization to critical section
problem and discuss briefly.
[8M]
b) What are the semaphores? How do they implement mutual exclusion?
[8M]
5
Consider the following page reference string: 1, 2, 3, 4, 2, 1, 5, 6, 1, 2, 3,
7, 6, 3, 2, 1, 2, 3, 6. How many page faults would occur for the
LRU,FIFO,LFU and optimal page replacement algorithms assuming two
and five frames?
[16M]
6 a) How can a system recover from a deadlock? Explain [8M]
b) Explain the Resource-Allocation Graph Algorithm for deadlock prevention.
[8M]
7 a)Explain the different file access methods in detail.
[8M]
b)Describe any two disk scheduling algorithms with suitable illustrations.
[8M]
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R13
SET – 1