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Sixth Semester B.E. Degree Examination, Aug./Sept. 2020
Operating Systems
3 hrs. Max. Marks: 80
Note: Answer any FIVE full questions, choosing ONE full question from each module.
Module-1
Define operating systems, What are multiprocessor systems? Explain their three main
advantages, (05 Marks)
‘Compare multi-programming and time sharing systems. (05 Marks)
Point out and explain the various operating system serviees. (06 Marks)
OR
What are microkernals? Point out their advantages
(05 Marks)
What are the two models of inter process communications? What are the strengths and
‘weakness of the two approaches? (05 Marks)
Compare and contrast, short term, medium term and long-term scheduling. (0 Marks)
Point out and explain the various benefits of multi threaded programming. (04 Marks)
Consider the five processes arrive at time 0, in the order given, with the length of the CPU
burst given in milliseconds.
Process | Burst time
Pr 10.
Pr 29)
Pa 3
Py 7
Ps 12
Consider the FCFS, SIF and RR (quantum = 10ms) scheduling, diaw the Gantt chart for
each of the scheduling. Determine average waiting time and tumaround time for all the
3 scheduling algorithm. Which algorithm would give the minimum average waiting time?
(12 Marks)
oR
What is the critical section problem point out and explain its three requirements. (0S Marks)
What are semaphores, explain how mutual exclusion is implemented with semaphores
: (05 Marks)
‘What is Dimming philosopher problem explain its monitor solution. (06 Marks)
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Modute-3
‘What are deadlocks? Point out and explain its necessary conditions. (04 Marks)
Explain the various methods of recovery from deadlock. (05 Marks)
Consider a system with five processes Pp through Py and three resources types A, B and C.
Resource type A has 10 instances, resource type B has 5 instances and resource type C has 7
instances suppose that, at time Ty, the following snapshot of the system.
‘Allocation’ Max | Available
A[B[C[A|B[C/A|B[C
C2
A
A
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Draw the need matrix.
‘The sequence
is sale state or not. (07 Marks)
OR
Define paging. Explain paging hardware with a neat block diagram. (08 Marks)
‘What is segmentation? Explain basic method of segmentation with an example, (08 Marks)
M
What is demand paging? Explain the steps in handling a page fault with a neat diagram.
(08 Marks)
Consider the following sequence
7.0.1,2,0,3.0,4,2,3,0,3, 2. 1, 2,0, 1, 7,0, 1
How many page faults occurs with three page frames
i) FIFO
ii) Optimal page replacement
iii) LRU page replacement algorithm. (08 Marks)
OR
‘What is a file? What are its attributes, explain file operations (06 Marks)
Explain what are the different types of files. (0s Marks)
Explain file system mounting. (05 Marks)
Module-5
Explain various disk scheduling algorithm with an example. (10 Marks)
Explain access matrix protection system of O.S. (06 Mares)
oR
Explain the various. Components of the Linux system. (08 Marks)
Explain the process management in Linux. (08 Marks)
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