Virtual Memory Flashcards
1
Q
What does virtual memory mean?
A
It means that there is no chance of programs overwriting each other
2
Q
What does segmentation allow?
A
It allows us to divide the memory space into purposeful segments and assign virtual addresses to them
3
Q
What are the problems with segmentation?
A
- Still have to load libraries multiple times
- Still can’t use more memory than actually exists
- Programs will never have access to a full segment: some of it is used for addressing
- Problems with memory holes not fixed
4
Q
What does paging do?
A
Paging splits available RAM into pages which give programs virtual space.
5
Q
What are pages useful for?
A
They can be re used to save memory
6
Q
How does the OS load data from secondary storage to RAM?
A
- It determines the location of data on disk
- Obtains an empty page from RAM to use as a container for the data
- Load the requested data into an available page
- Update the page table to refer to the new page
- Return control to program
7
Q
What is swapping?
A
A way of moving a whole process from the RAM onto the HDD
8
Q
What does swapping do?
A
Saves the status of the currently running program
9
Q
Is swapping or paging slower?
A
Swapping is very slow, while paging is slow.
