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Operating Systems - Dec 2015
Computer Engineering (Semester 5)
TOTAL MARKS: 80
TOTAL TIME: 3 HOURS
(1) Question 1 is compulsory.
(2) Attempt any three from the remaining questions.
(3) Assume data if required.
(4) Figures to the right indicate full marks.
Attempt any four question:
1 (a) Differentiate between Monolithic and Microkernel.(5 marks)
1 (b) Explain effect of page size on performance.(5 marks)
1 (c) Draw and explain five state process models.(5 marks)
1 (d) Explain disk cache.(5 marks)
1 (e) Explain "chmod" command in UNIX.(5 marks)
1 (f) What do you meant by 'Busy Waiting'? What is wrong with it?(5 marks)
2 (a) Explain in detail file management in UNIX.(10 marks)
2 (b) Explain dining philosopher problem and solution to it.(10 marks)
3 (a) What is deadlock? Explain necessary and sufficient conditions to occur deadlock. what is the difference between Deadlock avoidance and prevention?(10 marks)
3 (b) Consider the following set of process with CPU burst time.
Process | Burst Time | Arrival Time |
P1 | 10 | 11 |
P2 | 04 | 2 |
P3 | 05 | 3 |
P4 | 03 | 4 |
i) Draw Gnatt chart for CFS, SJF pre-emptive and Round Robin (Quantum=0.3). Calculate average waiting time and average turnaround time.(10 marks) 4 (a) What is Operating System? Explain different functions and objectives of operating system.(10 marks) 4 (b) What is mutual exclusion? Give software approach for mutual exclusion.(10 marks) 5 (a) Consider following snapshot at time T0:5 processes P0 through P4.3 resources types A(10 units), B(5 units) and C(7 units).
ALLOCATION | MAX | AVAILABLE | |||||||
A | B | C | A | B | C | A | B | C | |
P0 | 0 | 1 | 0 | 7 | 5 | 3 | 3 | 3 | 2 |
P1 | 2 | 0 | 0 | 3 | 2 | 2 | |||
P2 | 3 | 0 | 2 | 9 | 0 | 2 | |||
P3 | 2 | 1 | 1 | 2 | 2 | 2 | |||
P4 | 0 | 0 | 2 | 4 | 3 | 3 |
i) Compute "Still Need" matrix?
ii) Is system currently in safe or unsafe state? Why?(10 marks) 5 (b) Explain various I/O buffering techniques.(10 marks) 6 (a) What is system calls of operating systems? Explain any five systems calls.(10 marks) 6 (b) Explain techniques of disk scheduling.(10 marks)