Assignment 1 – Introduction to operating system, memory and process management
This assignment focuses on the important characteristics and functions of Operating Systems.
Multiple Answer questions regarding OS operation must be answered by students. They will also need to report on certain OS aspects and algorithms, such as process scheduling, virtual memory, and mobile operating system.
Students should be able:
Compare and contrast external fragmentation and internal fragmentation. Give an example to show your reasoning.
Your answer should be based on reason
For efficient use of the memory, memory compact/relocation should be performed.
How would you rate the benefits and drawbacks of doing it more often?
Given the following loading times, decide in what order pages are replaced using the FIFO algorithm.
Time at which page was loaded into memory
Describe the simplified version LRU.
Use the table below to determine the order in which the pages will be replaced by the simplified LRU algorithm. Explain why.
Below are the arrival and CPU cycle times.
Time of Arrival
You can draw a timeline for each one of these scheduling algorithms. Also, show details about the queue formation during this time line
Round Robin (use time quantity of 3)
Use either books or internet resources to understand the concepts of turnaround time and waiting time.
These terms (waiting and turnaround time), can be defined in your own words.
Next, calculate the turnaround time for each job using all four scheduling algorithms. (Details are essential).
Comparison of the external and internal fragmentation
External fragmentations are caused by the variable-sized memory used to allocate the processes.
Internal fragmentations are generally caused by the allocation of the process to the fixed-sized memory.
External fragmentation occurs when a process that was previously allocated is deleted from the allocated memory.
Internal fragmentations occur when memory is not allocated for a process and is used to allocate additional memory.
Internal fragmentation can be solved using the paging, segmentation, and compaction techniques.
Implementing the best-fit technique solves external fragmentation.
The compaction technique is usually used before the running phase begins.
Compilers and assemblers generate executable files.
The files’ lowest addresses start at zero.
The object code must be modified so that the correct addresses can be identified during runtime.
The pages to be replaced in the following order: 3,16-8,1,18,4,15 and 12.
The LRU techniques use the status bit.
The status bits are used by the LRU techniques to identify entries and denote their validity.
The queue is removed from entries that have not been used in a while.
The pages will be replaced in the following order: 18,128,8,3,0 and 16,16,14,6.
The turnaround time is the total time it takes to complete a job.
The total waiting time is the time it takes for the job to be completed.
TOTAL TURNAROUND TIMES = (11+22+24+23+23+20), = 100
AVERAGE TOURNAROUND TIME=(100/4)=25
TOTAL TURNAROUND TIMES = (20+31+4+1+4)=60
AVERAGE TOURNAMENT TIME=(60/4)=15
TOTAL TURNAROUND TIMES = (12+3+0+20),= 35
AVERAGE TOURNAROUND TIME=35/4)=8.75
TOTAL TURNAROUND TIMES = (29+31+24+3+0), = 87
AVERAGE TOURNAROUND TIME = (87/4)=21.75
 Moraru (I.), Andersen (D.G.), Kaminsky (19.), M., Tolia (19.), Ranganathan (P.) and Binkert (19.).
Safe, reliable, and consistent memory management for non-volatile main memory that is byte-addressable.
Proceedings of the First ACM SIGOPS Conference for Timely Results in Operating Systems (p.
 Sirohi (A.), Pratap (A.) and Aggarwal (M. Improvised Round Robin Scheduling Algorithm.
International Journal of Computer Applications 99(18), pages 40-43, 2014.