Memory management facilities

The UNIX system provides a complete set of memory management mechanisms, providing applications complete control over the construction of their address space and permitting a wide variety of operations on both process address spaces and the variety of memory objects in the system. Process address spaces are composed of a vector of memory pages, each of which can be independently mapped and manipulated. Typically, the system presents the user with mappings that simulate the traditional UNIX process memory environment, but other views of memory are useful as well.

The UNIX memory-management facilities:

• Unify the system's operations on memory.

• Provide a set of kernel mechanisms powerful and general enough to support the implementation of fundamental system services without special-purpose kernel support.

• Maintain consistency with the existing environment, in particular using the UNIX file system as the name space for named virtual-memory objects.