Browse Prior Art Database

Partial Page Transfer for Expanded Data Storage

IP.com Disclosure Number: IPCOM000102224D
Original Publication Date: 1990-Nov-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 2 page(s) / 63K

Publishing Venue

IBM

Related People

Liu, L: AUTHOR

Abstract

A technique is described whereby protocols are provided for sub-page consecutive data transfer between main and expanded storage of computer memory. The concept provides increased flexibility in the sharing of data in expanded storage facilities.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Partial Page Transfer for Expanded Data Storage

       A technique is described whereby protocols are provided
for sub-page consecutive data transfer between main and expanded
storage of computer memory.  The concept provides increased
flexibility in the sharing of data in expanded storage facilities.

      Typically, the transfer of data between an expanded storage
facility and main storage is through the use of PAGEIN or PAGEOUT
instructions.  Since each transfer deals with an integral page, in
certain environments it is beneficial to be able to transfer a
partial page between two storage hierarchies.  For example, assume
that the expanded store is shared by two processors or two different
systems utilizing different main memories.  It is often desirable to
have two systems work concurrently on the data within the same page.
The two systems would modify the data at different halves of the
page.  At some point these modifications are to be reflected to the
expanded store. With the PAGEOUT instruction, problems can occur with
data integrity.  The first system can output the page which contains
its modifications to the first half of the page and the second system
PAGEOUT can modify its page, which will overwrite the modifications
originally updated by the first system.  The result is a loss of up-
to-date data contents. In addition, it should also be possible to
able to fetch partial data of a page from expanded storage.

      The concept described herein provides en...