Introduction to Paged Virtual Memory Answers 1. What does the Optimal Algorithm do in page replacement? A. Replaces the page with the highest priority B. Replaces the page that is currently least frequently used C. Replaces the page that will not be used for the longest time in the future D. Replaces the page that has been in memory the longest Answer: Replaces the page that will not be used for the longest time in the future (C) The Optimal Algorithm aims to replace the page that will not be needed for the longest period in the future. 2. Which of the following is a benefit of paged virtual memory? A. It allows programs larger than available RAM to execute B. It reduces the complexity of physical memory layout C. It ensures optimal performance at all times D. It eliminates the need for secondary storage Answer: It allows programs larger than available RAM to execute (A) Paged virtual memory enables the execution of programs larger than the available RAM by loading only necessary pages. 3. What is one of the main challenges associated with paged virtual memory? A. It guarantees high speed access to all memory B. It eliminates the need for memory protection C. It simplifies the management of page tables D. It introduces overhead due to TLBs and page tables Answer: It introduces overhead due to TLBs and page tables (D) Overhead is introduced in processing memory requests due to translation lookaside buffers (TLBs) and page tables. 4. How does paged virtual memory affect system performance? A. It automatically manages memory usage without overhead B. It has no impact on system performance C. It can negatively impact performance due to disk swapping D. It significantly reduces performance issues with page faults Answer: It can negatively impact performance due to disk swapping (C) Paged virtual memory relies on disk swapping, which can lead to significant performance impacts and slower response times. 5. What is a key advantage of memory sharing in paged virtual memory? A. It lowers overall memory usage B. It guarantees that each process will have dedicated memory C. It allows processes to run independently in isolation D. It reduces the need for disk storage Answer: It lowers overall memory usage (A) Memory sharing allows different processes to share the same pages in memory, which helps in reducing overall memory usage. 6. What is the primary purpose of paged virtual memory? A. To reduce the program size B. To increase processor speed C. To enhance the graphics performance D. To use more memory than is physically available Answer: To use more memory than is physically available (D) Paged virtual memory allows systems to utilize more memory than is physically available by managing memory in fixed-size pages. 7. What does a page fault indicate? A. The requested page is not found in physical memory B. There's an error in the page table C. The requested page is already in memory D. The virtual address is incorrect Answer: The requested page is not found in physical memory (A) A page fault occurs when the system cannot find the requested page in physical memory, necessitating loading it from secondary storage. 8. Which statement best describes the page table? A. It is a type of software error checker B. It maps virtual page numbers to physical page numbers C. It stores the data contents of each page D. It translates physical addresses to virtual addresses Answer: It maps virtual page numbers to physical page numbers (B) The page table is crucial for translating virtual page numbers into corresponding physical page numbers. 9. How does the FIFO page replacement algorithm operate? A. It replaces the page that has been in memory the longest B. It randomly selects a page to replace C. It keeps all pages in memory indefinitely D. It replaces the least recently used page Answer: It replaces the page that has been in memory the longest (A) The FIFO algorithm replaces the oldest page in memory, maintaining a simple queue of pages. 10. Which component contains the physical frame number if a page is in memory? A. Virtual address space B. Page table entry C. Secondary storage D. Page replacement algorithm Answer: Page table entry (B) Entries in the page table include the physical frame number if the corresponding page is currently resident in physical memory. 11. Which memory concept serves as the logical address space a process sees? A. Virtual address space B. Physical address space C. Page fault D. Page frame Answer: Virtual address space (A) The virtual address space represents the logical view each process has, independent of the actual physical memory. 12. What is one drawback of the LRU page replacement algorithm? A. It requires significant hardware support B. It frequently leads to page faults C. It may require more complex data structures to track usage D. It is the simplest to implement Answer: It may require more complex data structures to track usage (C) While LRU is effective in page replacement, it often requires additional data structures to track the usage patterns of pages. 13. What challenges arise from storing the page table in main memory? A. It is not required for virtual memory management B. It makes memory management less efficient C. Address translation cycles are needed for the page table itself D. It slows down program execution significantly Answer: Address translation cycles are needed for the page table itself (C) When the page table resides in main memory, additional translation cycles are needed to access it, which can complicate and slow down memory management.