page table structures

Summary

Concept

• modern logical memory space is massive -> huge number of pages
• each page must have an entry in the page table -> hueg page table
  • high overhead
  • page table might itself be fragmented

Direct paging

• keep all entries in a single table

2-level paging

• page table is broken up into smaller sub-tables
• generally, the sub-tables are the size of a page

Inverted page table

• entries are indexed by frame number instead