This paper deals with the following mechanism for controlling the multiprogramming set in a demand paging system: processes are dynamically divided into several categories according to the number of page faults generated during their residence in main memory. A process is admitted into the multiprogramming set only if there is enough space free in the main memory to contain the number of pages corresponding to the current category of the process. Using a queueing network model of an interactive system with such a control mechanism we study the effectivenesss of the control considered, and, more particularly, its ability to partition the memory space according to the locality of processes.

ARCADE is a research project in computer architecture. We first discuss its motivations and goals, wich are primarily the design of a dynamically adaptive system, and the use of performance evaluation methods as a design tool. The resulting system is intended to serve as a support for education in computer architecture and operating systems. Then, we present the overall structure of the system, and finally, we consider in more detail hardware tools that will be provided for the dynamic adaptation to varying load conditions.