1. Write a one-page (400 words) review on an article about the subject of operating systems that appeared in a recent (since Jan 2016) computing magazine or academic journal. Give a summary of the article, including the primary topic, your own summary of the information presented, and the author’s conclusion. Give your personal evaluation of the article, including topics that made the article interesting to you and its relevance to your own experience. Be sure to cite your source (APA referencing). [25 marks]
2. Given the following information: [5 + 5 = 10 marks]
a. Use the best-fit algorithm to indicate which memory blocks are allocated to each of the four arriving jobs.
b. Use the first-fit algorithm to indicate which memory blocks are allocated to each of the four arriving jobs.
3. Compare and contrast internal fragmentation and external fragmentation. Explain the circumstances where one might be preferred over the other. [6 + 4 = 10 marks]
4. If a program has 471 bytes and will be loaded into page frames of 100 bytes each, and the instruction to be used is at byte 132, answer the following questions: [5 + 5 = 10 marks]
a. How many pages are needed to store the entire job?
b. Compute the page number and exact displacement for each of the byte addresses where the data is stored. (Remember that page numbering starts at zero).
5. Given that main memory is composed of only three page frames for public use and that a seven-page program (with pages a, b, c, d, e, f, g) that requests pages in the following order: a, c, a, b, a, d, a, c, b, d, e, f [5 + 5 + 5 = 15 marks]
a. Using the FIFO page removal algorithm, indicate the movement of the pages into and out of the available page frames (called a page trace analysis) indicating each page fault with an asterisk (*). Then compute the failure and success ratios.
b. Increase the size of memory so it contains four page frames for public use. Using the same page requests as above and FIFO, do another page trace analysis and compute the failure and success ratios.
c. What general statement can you make from this example? Explain your answer.
6. Five jobs arrive nearly simultaneously for processing and their estimated CPU cycles are, respectively: Job A = 12, Job B = 2, Job C = 15, Job D = 7, and Job E = 3 ms. [5 + 5 = 10 marks]
a. Using FCFS, and assuming the difference in arrival time is negligible, in what order would they be processed? What is the total time required to process all five jobs? What is the average turnaround time for all five jobs?
b. Using SJN, and assuming the difference in arrival time is negligible, in what order would they be processed? What is the total time required to process all five jobs? What is the average turnaround time for all five jobs?
7. Given the following information: [20 marks]
Calculate the start time and finish time for each of the five jobs using each of the following scheduling algorithms
d. Round robin (using a time quantum of 5, but ignore the time required for context switching and natural wait)