Virtual Memory

Fetch Policy

The fetch policy determines when a page should be brought into memory.

Two common alternatives:

  1. Demand Paging
  2. Prepaging

Demand paging only brings pages into main memory when a reference is made to a location on the page

  • Many page faults when process first started

Prepaging brings in more pages than needed

  • More efficient to bring in pages that reside contiguously on the disk