Browse Prior Art Database

Program to Determine and Present the Working Set Memory in OS/2 2.0

IP.com Disclosure Number: IPCOM000103602D
Original Publication Date: 1993-Jan-01
Included in the Prior Art Database: 2005-Mar-18
Document File: 2 page(s) / 62K

Publishing Venue

IBM

Related People

DeWitt, JE: AUTHOR [+4]

Abstract

Disclosed is a method of measuring the Working Set memory requirements of programs running in OS/2* 2.0. The Working Set for either a single process or the entire system can be measured.

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This is the abbreviated version, containing approximately 53% of the total text.

Program to Determine and Present the Working Set Memory in OS/2 2.0

       Disclosed is a method of measuring the Working Set memory
requirements of programs running in OS/2* 2.0.  The Working Set for
either a single process or the entire system can be measured.

      When doing analysis of memory usage of programs running in OS/2
2.0, it is not sufficient to determine the total number of pages
which have been loaded.  In order to determine the actual amount of
memory which is required by the program, the Working Set must be
determined.

      The definition of Working Set is taken from the classical
definition, which is, The set of memory (pages) which have been
referenced in the last N time intervals.

      In order to compute the Working Set in OS/2 2.0, it is
necessary to know the following things:
      =   Which pages have been referenced;
      =   Whether or not a particular page belongs to the specified
process, if measuring a single process;
      =   Some sense of when the pages are touched.

      The algorithm is:
      1.  The accessed flags are cleared from the Page Tables of the
applicable process(es).
      2.  A timer is started.  On each timer tick, for the Page
Tables of the selected process:
           a.  The pages which have been accessed are noted.
           b.  The accessed flags are cleared.
           c.  If measuring a single process, for each page which has
been newly accessed, determine its owning Memory Objec...