A LAYERED VIRTUAL MEMORY MANGER
A. H. Mason · 1977
This thesis presents a specification for the Multics virtual memory manager. The virtual memory manager is that part of the operating system which coordinates the usage of physical memory and which manages the bindings between logical memory and physical memory. In the case of Multics, physical memory is composed of fixed-length blocks called frames and logical memory consists of segments, representing sets of frames. The original specification is out of date and obsolete because it describes an overly complicated structure and ignores the issue of resource control. The specification described here compatibly updates the functionality of the Multics virtual memory manager, simplifies the requisite structure, and addresses resource control problems. The specification is in the form of a model, using the methodologies of type extension and layers of abstraction. These methodologies provide the tools to develop a precise model structure, which is capable of handling the intricacies of resource control. The end result is organizational simplicity, certifiability, and comprehension.