"Although the byte may be the lowest addressable unit
of memory within Linux®, it's the page that serves as the
managed abstraction of memory. This article begins with a
discussion of memory management within Linux, and then explores the
methods for manipulation of user address space from the kernel.
"In Linux, user memory and kernel memory are independent and
implemented in separate address spaces. The address spaces are
virtualized, meaning that the addresses are abstracted from
physical memory (through a process detailed shortly). Because the
address spaces are virtualized, many can exist. In fact, the kernel
itself resides in one address space, and each process resides in
its own address space. These address spaces consist of virtual
memory addresses, permitting many processes with independent
address spaces to refer to a considerably smaller physical address
space (the physical memory in the machine). Not only is this
convenient, but it's also secure, because each address space is
independent and isolated and therefore secure."
Some of the products that appear on this site are from companies from which QuinStreet receives compensation. This compensation may impact how and where products appear on this site including, for example, the order in which they appear. QuinStreet does not include all companies or all types of products available in the marketplace.