An introduction to Linux kernel memory-related terms
Though system memory (also known as RAM) can be extended in some computers that allow it, physical memory is a limited resource in computer systems.
Virtual memory is a concept, an illusion given to each process so that it thinks it has large and almost infinite memory, and sometimes more than the system really has. To set up everything, we will introduce the address space, virtual or logical address, physical address, and bus address terms:
- A physical address identifies a physical (RAM) location. Because of the virtual memory mechanism, the user or the kernel never directly deals with the physical address but can access it by its corresponding logical address.
- A virtual address does not necessarily exist physically. This address is used as a reference to access the physical memory location by CPU on behalf of the Memory Management Unit (MMU). The MMU sits between the CPU core and memory and is most often part of the...
