Module 4.2 Operating Systems

Virtual memory

separation of user logical memory from physical memory

True or false

In Virtual memory

Virtual address space

logical view of how the process is stored in memory

Usually start at address 0, contiguous addresses until the end of space

• Demand paging

• Demand segmentation

Virtual memory can be implemented via

Virtual Address Space

sparse

address spaces with holes left for growth, dynamically linked libraries, etc.

System libraries

shared via mapping into virtual address space

fork

Pages can be shared during?

Demand Paging

Could bring the entire process into memory at load time or bring a page into memory only when it is needed

Lazy swapper

never swaps a page into memory unless page will be needed

pager

Swapper that deals with pages

True

True or False?

• With swapping, the pager guesses which pages will be used before swapping them out again

fork(),

Pages can be shared during speeding process creation

Demand Paging

Could bring the entire process into memory at load time Or bring a page into memory only when it is needed

swapping

With_____, the pager guesses which pages will be used before swapping them out again