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- In order to effectively manage virtual memory the operating system adopts
the following memory management strategies:
- Demand Paging
- only pages that a process demands are
brought into memory,
- Pages that have been modified are swapped out to
a swap file when the system starts to run out of memory,
- Discarding Pages
- Pages that can easily be re-read from
an image or data file are discarded when the system starts to
run out of memory,
- Shared Libraries
- Useful code is put into shared libraries so
that it is not duplicated.
- There has to be a close interaction between the operating system and
the CPU in order to correctly utilize virtual memory.
Linux runs on a number of very different hardware platforms and so
it must separate out the hardware specific code and data structures
from the operating specific code and data structures.
- The operating system runs from physical memory.
David A. Rusling