Cisy 300:Computer Operating System Question Paper
Cisy 300:Computer Operating System
Course:Computer Science
Institution: Kenya Methodist University question papers
Exam Year:2012
KENYA METHODIST UNIVERSITY
END OF 3''RD ''TRIMESTER 2012 (EVENING) EXAMINATIONS
FACULTY : COMPUTING AND INFORMATICS
DEPARTMENT : COMPUTER SCIENCE AND BUSINESS
INFORMATION
UNIT CODE : CISY 300/BBIT 213
UNIT TITLE : COMPUTER OPERATING SYSTEMS
TIME : 2 HOURS
Instructions:
Answer question one and any other two questions.
Question One
Discuss five major functions of operating systems.
(5 marks)
Distinguish between:
I/O bound and CPU bound processes.
(2 marks)
Preemptive and non preemptive scheduling algorithm.
(2 marks)
What are the advantages and disadvantages of batch systems?
(4 marks)
What is virtual memory management and what are its advantages?
(5 marks)
With reference to operating system concept, define a process. State and explain five process states.
(6 marks)
Describe the difference between external and internal fragmentation. Which of the two is most likely to be an issue of dynamic partitioning?
(3 marks)
The part of operating system that manages memory is called the memory manager. Explain the three functions of memory manager.
(3 marks)
Question Two
The table below shows jobs submitted in a computer system time sharing capability.
Job Arrival Time CPU Burst
A 0 12
B 1 2
C 3 1
D 5 5
The arrival time and CPU burst are arbitrary units using the reports:
Construct a Gantt chart for FCFS, SJF, SRT and RR (Time/Slice=2) scheduling algorithm.
(4 marks)
For each algorithm, work out the average turn around time (TAT) at average waiting time (AWT).
(8 marks)
Which of the algorithm provides optimal values for ANT and ATT? (1 mark)
Is ye the answer consistent with your expectation? Explain
(1 mark)
Describe a deadlock.
(2 marks)
What are various measures undertaken to prevent deadlocks?
(4 marks)
Question Three
Briefly explain the role of device drivers.
(4 marks)
Explain the following file allocation methods and state the advantages and disadvantages of each.
(6 marks)
Contiguous allocation.
Linked list allocation
Explain the following terms related to concurrency.
(8 marks)
Critical condition
Mutual exclusion
Race condition
Starvation
Explain the advantage of intermit driven ILO over programmed ILO.
(2 marks)
Question Four
Describe paged memory allocation concept and its two disadvantages.
(4 marks)
With reference to process management, what is a threat?
(2 marks)
1. Discuss four advantages of multithreading operating systems.
(8 marks)
For each of CPU scheduling algorithm below, describe to what extent each meets the qualities of a good scheduling algorithm.
1. Shortest job first. (SJF)
2. Round Robin (RR)
3. FCFS. (6 marks)
Question Five
Distinguish between best, first and next fit in context of dynamic memory allocation.
(6 marks)
State two possibilities that exist, in terms of process execution, when a process creates a new process.
(2 marks)
What is a page fault?
(2 marks)
Briefly describe the relocation and protection problem in memory management.
(3 marks)
Explain three page replacement algorithms.
(6 marks)
Describe the race condition in process management.
(1 mark)
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