4.3. Paged Memory Management

  • A page is a unit of logical memory of a program
  • A frame is a unit of physical memory
  • All pages are of the same size
  • All frames are of the same size
  • A frame is of the same size as a page

../_images/PMT.png

4.3.1. Using the Page Table

../_images/paged_lookup.png

  • To produce a physical address, you first look up the page in the PMT to find the frame number in which it is stored. Then multiply the frame number by the frame size and add the offset to get the physical address.
  • A page table is kept in main memory. It is part of the process control block (PCB) for each process.
  • Page-table base register (PTBR) points to the page table.
  • Page-table length register (PRLR) indicates size of the page table.
  • In this scheme every data/instruction access requires two memory accesses. One for the page table and one for the data/instruction.

4.3.2. Windows PMT

../_images/windows_pmt.png

4.3.3. Linux PMT

../_images/linux_pmt.png