Section 12.9
Review Questions
Fragmentation
  1. What is a hole in memory? How do they form?
answer...
a chunk of memory that is not currently being used
  1. What do some systems do when there are too many holes in memory and not enough memory to run jobs?
answer...
compact memory -- relocated all programs to one end of memory and collect all the holes into one big chunk of free memory
  1. What is the difference between external fragmentation and internal fragmentation?
answer...
external fragmentation happens between programs, whereas internal happens within programs
  1. What kind of fragmentation can occur in paged memory systems that does not occur in the CDC-style systems?
answer...
internal (though this is debatable)
  1. What would increasing the page (frame) size do to fragmentation in a virtual memory system? (increase or decrease it)
answer...
increase
  1. Why wouldn't computer designers opt for smaller pages when they know they can minimize fragmentation this way?
answer...
smaller pages would mean lots more entries in page tables, hence more memory would be devoted to page tables.