CS 3733 Operating Systems Notes: Virtual Memory Examples

Real Page Tables

Real page tables often contain information in addition to a valid bit and a frame number. Some typical bits include:

Real page tables often have several levels:

Address Translation in Win 2000

Address Translation in the Alpha AXP Model 21064 64-bit virtual address (43 bits used)
64-bit page table entries
8K page size
Virtual address:

              2               10       10        10        13
            |seg| unused | Level 1 | Level 2 | Level 3 | Offset |
seg=00 and seg=01: seg0 = text and heap
seg=10: kseg - kernel, no memory management
seg=11: seg - stack

Traditional Unix Page Replacement

Page Replacement in Solaris

Page Replacement in Win 2000