Quiz 12.8

DIRECTIONS: Read each question carefully. Then click on the dot next to the answer that most closely fits the question. Try to answer all questions on this quiz and when you are done, click on the grade me button at the bottom.

Coverage: Section 12.9

  1. Which of the following statements about the sizes of pages and frames is true?
they usually differ
page sizes can vary on the same computer system between jobs
they are always a power of 2
they are usually larger than 16,384 bytes

  1. What happens if the page size is very large?
internal fragmentation rises
loading a page from the swap area takes more time
the size of the page table goes down
all of the above

  1. How big is the virtual address space on a 32-bit computer (if all bits are available for addresses)?
4 MB
4 GB
4 KB
4 TB

  1. If there are 4096 frames of real memory in a computer system, how wide will the frame number be?
10 bits
12 bits
20 bits
24 bits

  1. Suppose that each page table entry requires 50 bytes (not bits). There are 1,048,576 pages in virtual memory. How much of the memory would be devoted to page table?
50 MB
5 MB
1 MB
can't tell without knowing how many jobs are active in the computer

  1. What nasty thing might happen if the program contained a very large loop in the code?
if the loop straddles a page boundary, it might cause more page faults
if the loop is contained wholy within a page, it might cause fragmentation
if the loop straddles a page boundary, the frame size might need to be increased

  1. What would happen to the size of the page tables if the number of bits in an address is increased?
the page tables would have to be much larger
the page tables would stay the same size if the pages were larger
the operating system might have to restrict the virtual size of programs to a more reasonable number of bytes
all of the above

  1. Some systems put page tables into a relatively small but very high speed memory to speed up dynamic address translation. Which observation below might be true?
the TLB would no longer be needed
this would be necessary when the hit ratio goes above 90% on a conventional virtual memory system
this would lead to much more expensive computer