Virtual Memory Deep Dive: Mechanisms, Paging, and OS-Level Implementation
Virtual Memory Deep Dive: Mechanisms, Paging, and OS-Level Implementation Virtual memory is a fundamental abstraction in modern operating systems that decouples application memory from the underlying physical hardware. It enables process isolation, memory overcommitment, and sophisticated paging strategies that make multitasking possible on systems with limited RAM. In this article, we explore the underlying architecture, components, and behaviors of virtual memory with a focus on Linux internals and memory management units (MMUs). What is Virtual Memory? Virtual memory (VM) is a memory management capability that provides an application with the illusion of a large, contiguous address space, even though the physical memory (RAM) may be fragmented or insufficient to hold all active pages simultaneously. Modern CPUs support virtual memory through hardware-level address translation, using the Memory Management Unit (MMU) and page tables. Core Concepts in Virtual Memory...