Virtual Memory

Chapter 12:-

1. Virtual memory is an abstraction of the primary memory of a von Neumann computer.

2. LRU or Least Recently Used has become the most widely used of the static replacement algorithms because it is a reasonable predictor for program behavior and its produces good performance on wider variety of page reference streams. The LRU is design to take care of spatial locality. This means that if the page has been reference recently, there is a high chance that it will be reference again. Thus, giving priority of page frames allocation.

3.For Static Paging Algorithm, the fetch policy decides when a page should be loaded into primary memory, replacement policy determines which page should be removed from primary memory if all page frames are full. The placement policy determines where the fetched page should be loaded in primary memory.