Question

information about all future page In optimal page replacement algorithm, references is available to the operating system (OS). A modification of the optimal page replacement algorithm is as follows: The OS correctly predicts only up to next 4 page references (including the current page) at the time of allocating a frame to a page. A process accesses the pages in the following order of page numbers: 4 1, 3. 2, 4, 2, 3, 1, 2, 4, 3, 1, 4. If the system has three memory frames that are initially empty, find the number of page faults that will occur during execution of the process.

Answer 1

6 page fault will occur as OS will se only the 4 pages to replace the pre exsisting pages in the memory frames and hence we will get 6 page faults for the first 4 pages then for the 8th page then for the 11th page