Bissoy.com
Doctors Medicines MCQs Q&A

Given reference to the following pages by a program 0, 9, 0, 1, 8, 1, 8, 7, 8, 7, 1, 2, 8, 2, 7, 8, 2, 3, 8, 3 How many page faults will occur if the program has three page frames available to it and uses an optimal replacement?

Given reference to the following pages by a program 0, 9, 0, 1, 8, 1, 8, 7, 8, 7, 1, 2, 8, 2, 7, 8, 2, 3, 8, 3 How many page faults will occur if the program has three page frames available to it and uses an optimal replacement? Correct Answer 7

The theoretically optimal page replacement algorithm when a page needs to be swapped in, the operating system swaps out the page whose next use will occur farthest in the future. For example, a page that is not going to be used for the next 10 seconds will be swapped out over a page that is going to be used within the next 5 seconds.

0, 9, 0, 1, 8, 1, 8, 7, 8, 7, 1, 2, 8, 2, 7, 8, 2, 3, 8, 3

F, F, H, F, F, H,H ,F,H, H, F,H, H,H, H,H, H,F, H, H

Related Questions

A computer has twenty physical page frames which contain pages numbered 101 through 120. Now a program accesses the pages numbered 1, 2, …, 100 in that order, and repeats the access sequence THRICE. Which one of the following page replacement policies experiences the same number of page faults as the optimal page replacement policy for this program?
A system uses FIFO policy for page replacement. It has 4 page frames with no pages loaded to begin with. The system first accesses 100 distinct pages in some order and then accesses the same 100 pages but now in the reverse order. How many page faults will occur?
A system uses FIFO policy for page replacement. It has 4 page frames with no pages loaded to begin with. The system first accesses 50 distinct pages in some order and then accesses the same 50 pages in reverse order. How many page faults will occur?
Fact 1: Eyeglass frames cost between $35 and $350.
Fact 2: Some eyeglass frames are made of titanium.
Fact 3: Some eyeglass frames are made of plastic.

If the first three statements are facts, which of the following statements must also be a fact?
I: Titanium eyeglass frames cost more than plastic frames.
II: Expensive eyeglass frames last longer than cheap frames.
III: Only a few eyeglass frames cost less than $35.
Determine the number of page faults when references to pages occur in the following order : 1, 2, 4, 5, 2, 1, 2, 4. Assume that the main memory can accommodate 3 pages and the main memory already has the pages 1 and 2, with page one having brought earlier than page 2. (LRU page replacement algorithm is used) 
Applying the LRU page replacement to the following reference string. 1 2 4 5 2 1 2 4 The main memory can accommodate 3 pages and it already has pages 1 and 2. Page 1 came in before page 2. How many page faults will occur?
How many page faults will occur if Optimal Page replacement algorithm is used for the following reference string with three page frames? 7, 0, 1, 2, 0, 3, 0, 4, 2, 3, 0, 3, 2, 1, 2, 0, 1, 7, 0, 1
Consider the following page reference string: 1, 2, 3, 2, 4, 1, 3, 2, 4, 1 Assume that there are three-page frames which are initially empty. Let LRU, FIFO, OPTIMAL denote the number of page faults under the corresponding page replacement strategy. Then, which of the following is TRUE?
A computer has sixteen pages of virtual address space but the size of main memory is only four frames. Initially the memory is empty. A program references the virtual pages in the order of 0, 2, 4, 5, 2, 4, 3, 11, 2, 10. How many page faults occur if LRU page replacement algorithm is used?
Consider the virtual page reference string 1, 2, 3, 2, 4, 1, 3, 2, 4, 1 on a demand paged virtual memory system running on a computer system that has main memory size of 3 page frames which are initially empty. Let LRU, FIFO and OPTIMAL denote the number of page faults under the corresponding page replacement policy. Then