Chapter 32 Flashcards
What are 2 techniques for contiguous memory allocation for a process
- MVT
2. MFT
What are 2 issues in MFT
- Waist memory space
2. Load time address binding
How waist memory space
It can be from 2 ways.
- At a time one process takes place. The rest of memory other than process occupies remains waist. It is also known as internal fragmentation.
- It is possible whole partition is being wasted. It is because a process goes to according to its size into memory partition and there might be no such a process that falls on a specific memory partitions. Thus, it will remain useless.
Does MVT have internal fragmentation or external fragmentation
External fragmentation
Does MVT have dynamic address binding
Yes
What is external fragmentation
We have holes in memory because of multiple processes come and go and we have enough space to load a new process but could not load because space is not contiguous. Then it is called external fragmentation. e.g. there are 3 holes 100k, 200k and 300k respectively. And we have a new process of 310k then we can not load it although we have 600k overall space in holes but it is not contiguous.
What is compact / de fragmentation of memory
Making all memory in one place to make it contiguous
What is memory move
Moving process to in and out in de fragmentation process is called memory move.
What is paging
Latest memory techniques like virtual memory uses paging. Divide physical memory into fixed-size blocks called frames. Divide logical memory into blocks of the same size, called pages.
What is typical page size
1k - 6k
Does size of a page power of 2
Yes
What is the relationship between pages and frames
Program pages loads into frames
What is page table
Keep track of a program’s pages in the main memory by using the page table.
