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Paging is used to map the virtual address space to the physical address space.

Address | Segmented in | Offset | virtual $v = (s, wv)$ | $s$ pages | $wv$ bytes | physical $p = (k, wp)$ | $k$ frames | $wp$ bytes |

with $wv = n \cdot wp, n \in {\mathop{\mathbb N}}$ (default $n=1$)

Page Table

One entry per page. Entry:

Frame number | physical frame | P-Bit | is page present in frame | R-Bit | is page referenced | M-Bit | is page modified (dirty) | X-Bit | is page data executable |

Page Fault

Event that occurs when a program tries to reference a page not currently present in RAM.

Page Replacement Algorithm

Working Set Concept

The working set of a process is the set of pages expected to be used by that process during some time interval. It can be used to determine pages for replacement that do not belong to the working set.