YEAR 1 CO1 WEEK 24 MEMORY MANAGMENT

Question 1

What is memory management and why is it important?

Answer 1

Memory management is necessary to organise use of main memory by converting logical addresses to physical addresses.
Most vital resource computer needs is to manage is memory.

Question 2

Define A Logical Address

Answer 2

Addresses at which an item appears to reside, generated by CPU.

Question 3

Define Physical Addresses

Answer 3

Actual physical location of the storage cell in memory.

Question 4

What needs to happen for a executable application to be run.

Answer 4

To run a process it has to be loaded into main memory.
To run more than one process all have to be in main memory at the same time.
When executable application loaded into main memory it becomes a ‘process’ and requires memory to run.

Question 5

Describe Segmentation.

Answer 5

OS sets aside memory for process to use. This is called segmentation.
A way of portioning memory.
Variable Sized based on contents.
Are logical divisions which hold complete sections of programs.

Question 6

Define Paging.

Answer 6

Second type of memory management which designed to handle virtual memory.

Question 7

Define a Page.

Answer 7

A fixed sized physical division of memory. Each page is contiguous.

Question 8

Describe Pagination.

Answer 8

When RAM full memory manager determines least used page.
Page then copied into virtual memory.
Free area renumbered by memory manager and marked as free to use.
If page needed again swapped back into RAM.
ONLY USED WHEN VIRTUAL MEMORY IN USE.

Question 9

What is Disk Thrashing.

Answer 9

When Virtual Memory in heavy use.
As more pages are swapped eventually more time is being spent swapping pages than processing data.