Page 135 - DCAP403_Operating System

Operating System

Notes Figure 7.7: Sharing of Segments in a Segmented Memory System

editor

segment 0 43062
limit base
data 1 0 25286 43062
segment 1 1 4425 68348 editor
segment table
logical memory process P 1 68348 data 1
process P 1 72773

90003
editor data 2
98553
segment 0
data 2 limit base physical memory
0 25286 43062
segment 1 1 8850 90003
segment table
logical memory process P
process P 2 2

Task Differentiate between paging and segmentation technique.

7.7 Segmentation with Paging

Figure 7.8: Diagram of Segmentation with Paging

Virtual Address
Seg# Page# Offset

Main Memory

Segment Table Page Table

Segments can be of different lengths, so it is harder to find a place for a segment in memory than
a page. With segmented virtual memory, you get the benefits of virtual memory but you still

have to do dynamic storage allocation of physical memory. In order to avoid this, it is possible
to combine segmentation and paging into a two-level virtual memory system. Each segment

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