Operating Systems - Jun 2012
Computer Science Engg. (Semester 5)
TOTAL MARKS: 100
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any four from the remaining questions.
(3) Assume data wherever required.
(4) Figures to the right indicate full marks. 1 (a) What is an Opeating System? Bring out the requirements of.
(i) Real time operating systems
(ii) Distributed operating systems. (10 marks) 1 (b) What are system calls? Explain the different categories of the system calls.(10 marks) 2 (a) Explain the process state with a diagram. What is the need for a context switch?(7 marks) 2 (b) What are the differences between user level threads and kernal supported threads?(5 marks) 2 (c) For the following example calculate average waiting time and average turn around time by using FCFS, preemptive SJF and RR (1 time unit) CPU scheduling algorithms.
|Jobs||Arrival time||Brust time|
Calculate the content of matrix need and find out safe sequence by using Banker's algorithm.(8 marks) 5 (a) Distinguish between:
(i) Logical address space and physical address space
(ii) Internal fragmentation and external freagmentation
(iii) Paging and segmentation(6 marks) 5 (b) Explain with the help of supporting hardware diagram how the TLB improves the performance of a demand paging system.(10 marks) 5 (c) Given memory partitions of 100 k, 500 k, 200 k, 300 k and 600 k (in order) how would each of the first fit, best fit and worst fit algorithms work place processes of 212 k, 417 km, 112 k and 426 k (in order)? Which algorithm makes the most effiecient use of memory?(4 marks) 6 (a) Explain the different types of files.(5 marks) 6 (b) Name the different file allocation methods. Explain the linked allocation of file implementation with merits and demetis.(8 marks) 6 (c) Define file system. Explain the different directory structure.(7 marks) 7 (a) What is disk scheduling? Explain any three disk scheduling methods with examples.(10 marks) 7 (b) What is swap space management? Explain.(5 marks) 7 (c) What is access matrix? Explain the access matrix with domains as objects.(5 marks)
Write short notes on the following :-
8 (a) Process management in Linux.(6 marks) 8 (b) Page replacement algorithms.(8 marks) 8 (c) Steps in handling a page fault.(6 marks)