Virtual memory is a memory management technique used by operating systems to provide an “idealized abstraction of the storage resources that are actually available on a given machine,” creating the illusion to users of a very large main memory.
en.wikipedia.org
How Virtual Memory Works:
Address Mapping: The operating system, in conjunction with hardware, maps memory addresses used by a program (virtual addresses) into physical addresses in computer memory.
en.wikipedia.org
Paging: Memory is divided into fixed-sized blocks called “pages.” When the system runs out of RAM, it moves inactive pages to a space on the hard drive or SSD known as the “page file” or “swap space,” freeing up RAM for active processes.
geeksforgeeks.org
Segmentation: Some systems use segmentation, where memory is divided into variable-sized segments based on the logical divisions of a program, such as functions or data structures.
indeed.com
Benefits of Virtual Memory:
Isolation: Each process operates in its own virtual address space, preventing them from interfering with each other’s memory, which enhances system stability and security.
Efficient Memory Use: By moving inactive data to disk storage, virtual memory allows for more efficient use of RAM, enabling the execution of larger applications or multiple applications simultaneously.
Considerations:
While virtual memory allows systems to run larger applications than the physical memory would normally permit, excessive reliance on it can lead to performance issues. Accessing data from disk storage is significantly slower than accessing data from RAM, so frequent swapping (known as “thrashing”) can degrade system performance.
Understanding virtual memory is crucial for optimizing system performance and ensuring efficient resource utilization.
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