Virtual Memory in Operating System

In this video, we will be understanding what is Virtual Memory & what are the functions of Virtual memory in an operating system. Virtual Memory is a memory management technique. It allows the main memory to store programs that are larger in size compared to the main memory. It utilizes the secondary memory as if it was a part of the main memory. It gives an illusion that the computer has a large main memory.

Instead of keeping a single large program in the main memory, Virtual Memory allows for keeping parts of multiple programs in the memory at the same time. Parts of a program are swapped in and out of memory frequently. Virtual Memory maps Logical addresses to Physical addresses at run time using both hardware and software techniques. The process of loading a page in the main memory on demand is known as Demand Paging.

When a CPU is executing a process, the required page of that process must be present in the main memory at that time. In case, the CPU tries to access a page that is not present in the main memory, this situation is known as a Page Fault. Virtual Memory increases the degree of multiprogramming. Virtual Memory allows programs larger than the main memory to be executed by the OS. Improves CPU utilization by bringing in more programs in the main memory. The idle time of the CPU reduces.

Frequent swapping of pages between main memory and secondary memory makes the CPU slower. Implementing Virtual Memory reduces the amount of space available in the secondary memory.

Virtual memory in OS: https://www.geeksforgeeks.org/virtual-memory-in-operating-system/