Question

Virtual memory increases  degree of multiprogramming

Virtual memory  decreases degree of multiprogramming

Degree of multiprogrammoing means number of process is in memory. (and I think memory here is primary memory and not secondary memory such as disk or magnetic tape)

So, virtual memory must decreses use of main memory. But according to prediction it is wrong. Where Am I getting wrong?

Comments

@abhishek,

surely... page fault is happen in only due to virtual mem concept

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@Shaik Masthan I am slightly confused here. Why is no virtual memory required if secondary memory is lesser than the main memory? What if my program is small but declares an array of size more than main memory?

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@ gauravkc , then remaining pages of process where you kept?

Answer 1

• The number of process is present in main memory at any point of time is colled degree of multiprog.

• In virtual memory concept when process size is large then we can store part of the process in main mem which is required.

• So we can keep more number of process in main memory which is required . So it increse the degree of multiprog
• In earlier it is implemented bcz process size is larger.but it also implemented as only those pages is put in main mem which is required.
•  

Comments

but main memory does not hold all processes at the same time