Operating System Msc IT 2 Semester/Term University Of Sargodha (UOS) 2019

9968

02.

University of Sargodha

M.S6 2e Term Examination 2012

Subiect Information Technology

Paoers Onecating System (CMP-361D)

Time Allowed: 2130 Hours

Maximum Marka: 80

Note: Objective part is compulsory. Attempt any three questions from subjective part.

Objective Part

(Compulsory)

Q..

Write short answers of the following in 2-3 lines each on your answer sheet.

(16*2)

Suppose there is an organization which hired a person for dividing tasks among other persons. Which

multiprocessing environment does this organization depict?

Draw Interrupt Timeline clearly mentioning interrupt occurred by a proceus. -

What exactly do you mean by CONTENT in context switching?

iv.

V.

Vi.

VIE.

VilL

Differentiate between preemptive and non-preemptive scheduling

Which one of the following scheduling algarithms) could result in starvation? FCFS, S/f, Round Robin.

What is the difference between deadlock avoidance, prevention and detection?

What does it mean to Preempt a process?

rOund und both use previous information in page replacement policy. How is one different from

xiv.

XV.

xvi.

Q.2.

Q.3.

King with example.

Why SJE can't be used In real-time so boltment when you don't hive execution history of the meuco?

Write names of all preemptive and non-preemptive scheduling polietes.

free segment using first-lit, best-fit and worth?

Suppose that we have are segments with gize: 6, 17, 25, 14, and

15. Place a program mika sies in the

Subjective Part

Discuss the advantages and disadvantages of guaranteeing reliable transfer of data between modules in the

STREAMS abstraction.

a) Explain when a Deadlock can and when it cannot occur in the below scenario when two processes (PO, PI)

are competing for semaphore S=1 and Q-1.

Pol

valt (S):

P.

wait (Q):

wait (Q):

S

signal (5):

31gna1(9) :

signal (Q) :

aignal(S):

b.

How Peterson's solution preserves 3 properties for critical section problem i.e. Mutual exclusion,

Progress and Bounded-Waiting?"

(8)

0.4.

a) For the data given below:

Allocation

A BC

Need

Po

Pi

01.0

743

Available

ABC

230

302

020

302

60.0

P3

211

011

002

Apply Banker's algorithm and argue with reasoning whether requests should be granted or not.

Can request for (3,3,0) by 2, be granted?

-ON Can request for (0,2,0) by Po be grantea?

Ustad dire the memory organization schemes of Contiguous Memory Allocation, Segmentation, und

(6)

aging with respect to the following issues:

i External fragmentation

th Interny Dragmentation

Q.5.

Suppose m=5 (2) bytes), n=1, Physical AddieS Space = 144 bits.

What is Logical Address Space

What is Page Size?-

What is size of Page Number?

iv.

What are total number of pages in Main Memory?

%.

How many pages required to load this process in Main Memory?

Vi.

How many total Pages in Main Memory?

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(3)

(3)

(3)

(3)

(2)

vil

If OS takes 5 pages, how many others pages left for user processes?

Q.6.

8) Consider the following page reference using three frames that are initially empty. Find the puge faulty

using. Optimal algorithi

where the page relerence sequence: 7,0,1,2,0,3,0,4,2,3,0,1.2, 1.2,0,1,7,A,11 (6)

b) Apply LRU on dataset provided in Question 6 part a, and compare the results.

(O)

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