Browse Prior Art Database

Fast Tables Structure for Expanding Memory Manager

IP.com Disclosure Number: IPCOM000106059D
Original Publication Date: 1993-Sep-01
Included in the Prior Art Database: 2005-Mar-20
Document File: 2 page(s) / 82K

Publishing Venue

IBM

Related People

Brewer, JA: AUTHOR [+3]

Abstract

Disclosed is a software table structure used to control Expanded Memory Manager (EMM) pages. The technique allows EMM allocated logical pages representing physical addresses to be kept in contiguous sequence, and allows any EMM handles' logical page to be directly and quickly accessed as an offset from the start position of that handles' allocated pages.

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

Fast Tables Structure for Expanding Memory Manager

      Disclosed is a software table structure used to control
Expanded Memory Manager (EMM) pages.  The technique allows EMM
allocated logical pages representing physical addresses to be kept in
contiguous sequence, and allows any EMM handles' logical page to be
directly and quickly accessed as an offset from the start position of
that handles' allocated pages.

      Referring to the figure, we have a structure with two basic
tables.  Table 1 is the Handle Assignment Table (HAT) which contains
an index (start address) into the second table for each EMM handle
(up to 256 handles).  When table 1 is initialized, each handle's
pointer is set to a value beyond the end of the second table (3) to
indicate that the handle is not in use or assigned to any EMM
application.

      Table 2 is the Page Allocation Table (PAT) which consists of
three basic areas:  allocated handle headers 4 and their assigned
pages 5, empty page slots 6, and unallocated pages list 7.  A 4-byte
header is used to signify each handle and it is followed by a
sequential (EMM logical) list of the physical addresses for each page
allocated to the EMM handle.  Empty Page Slots area 6 is a work space
which is used during page allocation and deallocation.  Unallocated
pages area 7 is a list of physical page addresses currently
unassigned to any EMM handle.

      As a handle is assigned to an application, a header 4 is
created for it in PAT...