This question is about space allocation method for files on a magnetic hard drive. a. Contiguous allocation is a way of allocate blocks to files. However, it can suffer from over or under estimation. Describe one problem that each will cause. . Another way of allocation is to used linked blocks. The slides suggest using FAT (file allocation table) to improve the performance. How can FAT improve the performance?
5. (16 points) Consider deadlock avoidance with single resources. Assuming we have 4 process P1,P2, P3, P4. and 4 resources r1, r2, r3, r4. Consider all| 4 processes are writers (i.e. no resource scan be shared among processes). Suppose the processes are to acquire and release the release the resources in the following order (and assume the OS has the complete knowledge of the schedule beforehand) – we only show the first 8 requests. We also assume the following: if a request is denied, the process immediately quits and release all resources it is holding/waiting (if any). if a process have to wait for a resource (if another process is holding it), the avoidance algorithm can still grant the request and allow that process to wait all waiting queues for each resources are FIFO a.Draw the resource allocation graph before the first request is made b. Will the third request (P3 request r3) be granted? Explain your answer using the resource allocation graph. c. Is there any request after that one that will be denied? If so, show the first request that will be denied and explain why using the resource allocation graph. If not, show the request allocation graph at the of the 8-th request.
Consider the following code segment: pid_t pid; pid = fork(); if (pid == 0) { /* child process */ fork(); thread create( . . .); } fork(); a. How many unique processes are created? Explain. b. How many unique threads are created? Explain.
Can a multithreaded solution using multiple user-level threads with one kernel thread achieve better performance on a multiprocessor system than on a single processor system? Explain. Assume this process is the only one running on the system.
(10 points) Consider the reader-writer problem. The following are two potential solution to the problem .Neither of them work. Explain why. a.Writer code the same as slide 71 of synchronization, reader code as follows: Reader code the same as slide 71 of synchronization, writer code as follows
The next paper is an old but important publication in the history of operating systems. The paper is A. Bensoussan and R. Daley, "The Multics Virtual Memory: Concepts and Design", Proceedings of the Symposium on Operating Systems Principles, 1969." As usual, I would like a summary, followed by a separate section containing your reaction. As I continue to read your submissions, in many cases the summaries are better than the reaction sections, in the sense that they were given more attention, or they are so commingled that I can't tell the summary and reaction apart. Please physically separate the two sections (using 'Summary' and 'Reaction' headings would be a good way to do that) and give some serious, critical thought to what you have read.
This assignment includes two closely related (and reasonably short) papers, a landmark paper from Peter Denning describing working set theory and a paper from Carr and Hennessy on virtual memory management. Note that Hennessy is the other co-author of our Computer Architecture text. As usual, provide a summary and your reaction for each paper. Please refer back to the first couple of assignments and announcements for reaction expectations, this is a separate section of your report that is just as important as the summary. Peter Denning, "The Working Set Model for Program Behavior", Communications of the ACM, 1968. Richard Carr and John Hennessy, "WSClock -- A Simple and Effective Algorithm for Virtual Memory Management", Proceedings of the Symposium on Operating Systems Principles, 1981.
Q2. Consider a logical address space of 256 pages with a 4-KB page size, mapped onto a physical memory of 64 frames. a) How many bits are required in the logical address? b) How many bits are required in the physical address?
Problem 1.3 Office hours will be offered every week with both the professor and the TAs. These will be scheduled avoiding student class conflicts to the degree possible. Go to the below when2meet link. Sign in using an arbitrary but unique 5 digit number as your name. Select the times that are not in conflict with your other classes or other regularly scheduled obligations. https://www.when2meet.com/?18345682-IYhV4 Indicate the number you used below. What was your number on When2Meet?
Problem 1.4 Background: Excel uses specific syntax to represent functions (such as those shown below) into an Excel workbook sheet. Problem: Input the below expressions into the indicated calculation tables and substitute x for the the values: -1, 0, 3, and A. What are the outputs from excel, are there any errors? If so, what do they mean? Cite any reference used. Example: f(x) = x + 1 Expression 1. f(x) = 2*+15 Expression 2. f(x) = x! Expression 3. f(x) = e-5x Expression 4. f(x) = log5 (x - 2)