Use of Main Storage As a Fast Access Paging Device
Original Publication Date: 1985-Oct-01
Included in the Prior Art Database: 2005-Feb-19
In a virtual environment, fast access magnetic media are required for paging to get an acceptable level of performance. When there are fast access media failures, MAPs (maintenance analysis procedures) are used to diagnose the problem. As MAPs are initially used, they are paged in/loaded from a secondary device that has a much slower access rate and a directory is built containing the program's name, load point, and length. The actual program code is saved in another reserved main storage area. Whenever a program is needed, this directory is searched to see if the program was used before. If it was, a copy is made from the reserved main storage area to the correct load location. After a program has been run a first time, a flag is set and the program can only run at a preassigned address which is shared by many programs.