Operating System - Desklib

This article provides answers to questions related to Operating System. It includes information on logical and physical addresses, LRU algorithm, and FCFS scheduling algorithm. The article also includes a bibliography with references to relevant research papers.

Running head: OPERATING SYSTEM
Operating System
Name of the Student:
Name of the University:
Author Note

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OPERATING SYSTEM
Answer to question number 1
a. The address at the start of frame 1 is Page 4
b. Yes, Page 2 is mapped to the frame 2.
No page 3 is not mapped to frame 3
c. The pages which are not yet loaded into the memory as yet are pages 3,6 and 7.
d. When the address A is referenced any type of address in page 3, the CPU looks for the
table in the reference table. However, the CPU is unable to find page 3 in the table
and hence the CPU returns a miss. After the process, the system looks for the page in
the main memory and hence the logic address for the resources is referenced. After
the process gets the logical address, the CPU lets the process access the physical
address and allocates the resource of the address to the process. Hence the process has
to wait for all these time. Hence the waiting time for the process increases.
e. The address corresponding to the logical addresses are:
Logical Address Physical Address
1023 1
3000 2988
4120 4107
5000 1014
1023 mod log (1023) = 1
3000 mod log (3000) = 2988
4120 mod log (4120) = 4107
5000 mod log (5000) = 4987

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Answer to question number 2
a.
The pages would be replaced in the following order: 3, 16,8,1,18,4,15,12.
b. The LRU algorithm makes use of the status bit which is used for the validation of the
entries and the newer entries.
Order of replacement of the bit is in the LRU algorithm: 18,12,8,3,0,16,14,6.
Answer to question number 3
a.

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OPERATING SYSTEM
b.
Turnaround time: The total time required by the process to complete is known as the
turnaround time.
Waiting time: The total time a process has to wait before processing is known as the waiting
time.
FCFS
Process Arrival Time Burst Time Completion
Time
Turnaround
Time
Waiting
Time
A 0 12 12 12 0
B 2 5 17 15 10
C 4 2 19 15 13
D 6 11 30 24 13
E 9 1 31 22 21
Average Turnaround Time: (12+15+15+24+22)/5 = 17.6
Average Waiting Time: (0+10+13+13+21)/5 = 11.4

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Bibliography
[1] Moraru, I., Andersen, D.G., Kaminsky, M., Tolia, N., Ranganathan, P. and Binkert, N,
November. Consistent, durable, and safe memory management for byte-addressable non
volatile main memory. In Proceedings of the First ACM SIGOPS Conference on Timely
Results in Operating Systems (p. 1). ACM., 2013.
[2] Sirohi, A., Pratap, A. and Aggarwal, M. Improvised Round Robin (CPU) Scheduling
Algorithm. International Journal of Computer Applications, 99(18), pp.40-43., 2014.