International Business Machines Corporation

Patrick James Christenson

Michael Joseph Corrigan

David G Wenz

Bruce Marshall Walk

Michael Steven Faunce

Timothy John Mullins

Richard Karl Kirkman

Michael James McDermott

Glen Warren Nelson

Brian Eldridge Clark

Scott Alan Plaetzer

Paul LuVerne Godtland

Donald Arthur Morrison

Thomas Richard Crowley

David Nicholas Youngers

Russell Paul VanDuine

Edward John Rowlance

Craig W Martens

Robert J Hart

David C Naatz

An apparatus and method provide simultaneous local and global addressing capabilities in a computer system. A global address space is defined that may be accessed by all processes. In addition, each process has a local address space that is local (and therefore available) only to that process. An address space processor is implemented in software to perform system functions that distinguish between local addresses and global addresses. In the preferred embodiments, the local address space has a size that is a multiple of the size of a segment of global address space. When the hardware indicates a page fault, the address space processor determines whether the address being translated is a local address or a global address. If the address is a local address, the address space processor uses a local directory to process the page fault. If the address is a global address, the address space processor uses a global directory to process the page fault. When the hardware indicates an addressing error because a computed address crosses a global segment boundary, the address space processor determines whether the address is a local address or a global address. If the address is a global address, the address space processor indicates an addressing error. If the address is a local address, the address space processor determines whether the address is within the process' local address space, and indicates an addressing error if the address is outside the process' local address space. Instructions are allowed to operate on both local and global addresses because the address space processor handles either type of address whenever software assistance is required, such as for servicing a page fault or checking a segment boundary crossing. In addition, the address space processor dynamically checks the addressing compatibility of called code before passing control to the called code.

Apparatus and method for providing simultaneous local and global addressing using software to distinguish between local and global addresses

Method and apparatus for managing data on DASD units to improve system performance comprises monitoring portions of data on a plurality of DASD units to determine the times the data is accessed within a given time period, and characterizing accessed data portions of a DASD unit as HOT and COLD data. The DASD units are monitored to determine the number of times each unit is accessed within a time period to develop utilization factors reflective of the number of times the DASD unit is accessed during the time period. HOT and COLD data is moved between DASD units based on the utilization factors of the DASD units.

Dynamic DASD data management and partitioning based on access frequency utilization and capacity

A central processor holds a word-processing program and an entire document to be processed. A personal computer or intelligent terminal has an interactive display and holds code for some functions of the word processor, and stores individual pages of the document. As an operator performs editing tasks at the display, the personal computer performs locally those functions involving only the document page it holds. When additional document text is required to complete a function, the central processor performs the function on the full document. The central computer also performs all of certain other functions, regardless of where the data is stored.

Sharing word-processing functions among multiple processors

A central processor holds a word-processing program and an entire document to be processed. A smaller I/O processor, connected to the central processor and to an interactive display, holds code for some functions of the word processor, and holds a part of the document. As an operator performs editing tasks at the display, the I/O processor performs locally those functions involving only the document part it holds. When additional document text is required to complete a function, the central processor performs that part of the function involving the additional text.

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Lake City, MN, United States of America

Patrick James Christenson