Virtual memory — basic definition and mechanism: Which description best captures how virtual memory is commonly implemented in paged systems?

Introduction / Context:
Virtual memory provides the illusion of a large, contiguous address space by mapping virtual addresses to physical memory frames and secondary storage. Paging is the most widespread implementation technique.

Given Data / Assumptions:

• We consider standard paging based systems.
• Programs are divided into fixed size pages; RAM into frames.
• The MMU performs address translation at runtime.

Concept / Approach:

In paging, a process address space is split into pages. The OS maintains page tables that map virtual pages to physical frames or to disk locations when pages are not resident. This permits demand paging, protection, and efficient sharing of code segments, while decoupling the program's view from physical memory size.

Step-by-Step Solution:

Verification / Alternative check:

Operating system texts depict virtual memory with page tables, TLBs, and frames, verifying that subdivision into pages and frames is the canonical approach.

Why Other Options Are Wrong:

• Addresses generated by a processor: describes virtual address space, not the mechanism of virtual memory management.
• Processor time allocation: scheduling, not memory.
• Multiple programs in separate areas: true for multiprogramming but does not define virtual memory.

Common Pitfalls:

Confusing virtual address space with the paging mechanism; mixing CPU scheduling terms with memory management.

Final Answer:

is a method of memory allocation by which the program is subdivided into equal portions, or pages and core is subdivided into equal portions or blocks.