Operating Systems - Dec 2013
Information Technology (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. 1 (a) What is Kernel? Describe briefly the approaches of designing Kernel.(5 marks) 1 (b) What is real time operating system? Write the characteristics of real time operating system.(5 marks) 1 (c) In typical process state transition diagram. Clearly state under what condition the following state transitions occurs?
(i) Running to ready
(ii) Running to waiting
(iii) Waiting to ready(5 marks) 1 (d) What is Programmed I/O? Describe in brief.(5 marks) 2 (a) Consider a system running 10 I/O bound task and one CPU bound task. Assume that I/O bound issues an I/O operation once for every milisecond of CPU computing and that each I/O operation 10 miliseconds to complete. Also assume that the context switching overhead is 0, 1 milisecond and that all processes are long running task. what is the CPU utilization for round robin schedular when :
(i) the time quantum is 1 milisecond
(ii) the time quantum is 10 miliseconds?(10 marks) 2 (b) Describe the implementation of file allocation techniques.(10 marks) 3 (a) What is meant by interprocess communication? Explain shared memory and message passing.(10 marks) 3 (b) Consider the following page traces in demand paging system with 4 page frames :-
Determine the number of page faults and ratio using FIFO and LRU page replacement algorithms.(10 marks) 4 (a) Consider the following system snapshot using data structures in the Banker's algorithm
A B C D
A B C D
A B C D
|P0||6 0 1 2||4 0 0 1||3 2 1 1|
|P1||1 7 5 0||1 1 0 0|
|P2||2 3 5 6||1 2 5 4|
|P3||1 6 5 3||0 6 3 3|
|P4||1 6 5 6||0 2 1 2|
Using Banker's algorithm answer the following questions :-
(i) How many resources to type A,B,C and D are there?
(ii) What are the contents of Need Matrix?
(iii) Is the system is in safe state? find the state sequence if it is.(10 marks) 4 (b) Draw and explain architecture of RTOs.(10 marks) 5 (a) Suggest the implementation of binary semaphore that avoids the busy waiting.(10 marks) 5 (b) A 16 bit computer has page size of 1024 bytes. The page table of process is as
|Page No.||Frame No|
Determine the physical address corresponds to logical address
(i) 3720 (ii) 1125(10 marks) 6 (a) On a disk with 1000 cylinders, number 0 to 999, compute the number of tracks the disk arm must move to satisfy all request in the disk queue. Assume the last request serviced was at track 345 and head is moving towards track 0, the queue in FIFO order contains request for the following tracks:
Perform the computation for following scheduling algorithm :-
(i) FIFO (ii) SSTF (iii) SCAN(10 marks) 6 (b) What is thread? Explain user level threads and kernes level threads.(10 marks)
Write short notes on the following :
7 (a) NOs(5 marks) 7 (b) Different types of schedulars(5 marks) 7 (c) Distributed O.S.(5 marks) 7 (d) I-node(5 marks)