Operating Systems BSSE 4 Semester/Term UOS — University of Sargodha 2015

University of Sargodha

Department of Computer Science

Course Code:

Class: BSSE (Reg+Self)

Date: 12/04/2015

Operating System Concepts

4th

Time: 1hr 30 mins

Mid Term

Session: 2013-17

Total Marks: 20

Note: Attempt all the questions

Question # 1

A) Answer yes or no, or with a single term or short answer, as appropriate.

1. What approach to dealing with deadlock does the Banker's algorithm implement?

2. Which of the following scheduling algorithms can lead to starvation? FIFO, Shortest Job

First, Priority, Round Robin

3. A system that meets the four deadlock conditions will always/sometimes/never result in

dead-lock?

4. A cycle is a necessary and sufficient condition for deadlock in case of multiple instance of

each resource type

B) Answer the following questions briefly.

1. What is meant by multi-core multi-threaded systems?

2. What is the advantage of dynamic linking?

3. What is fragmentation? With what type of fragmentation paging and segmentation suffer

from?

Question # 2

1. Compute average turn-around time and average waiting time using SRF, SJF.

Process: P0 P1 P2 P3 P4 P5

Arrival Time: 1 2 3 5 6 7

CPU Time: 3 2 4 1 4 2

2. Draw process model for multilevel Queues

Question # 3

A) Consider a simple paging system with 2^16 bytes of physical memory, page size of 2^10 bytes, and

2^10 pages of logical address space. Answer the given questions on page table, and physical and

logical addresses for this system.

a. How many bits are in a logical address?

b. How many bytes in a frame?

c. How many bits in the physical address specify the frame?

d. How many entries in the page table?

B) Draw the hardware support required for Segmentation.