Browse Prior Art Database

Definition And Measurement Method of 'Working Set' When Analyzing Memory Utilization in OS/2

IP.com Disclosure Number: IPCOM000101212D
Original Publication Date: 1990-Jul-01
Included in the Prior Art Database: 2005-Mar-16
Document File: 1 page(s) / 50K

Publishing Venue

IBM

Related People

Summers, JH: AUTHOR

Abstract

Disclosed is a definition and measurement method for determining the 'working set' memory requirements for programs running under OS/2*.

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Definition And Measurement Method of 'Working Set' When Analyzing Memory Utilization in OS/2

       Disclosed is a definition and measurement method for
determining the 'working set' memory requirements for programs
running under OS/2*.

      What constitutes a 'Working Set'?  A definition that has been
used is:  That set of memory (code and data) which is required for
'acceptable' performance in a given environment for a given scenario.

      In paging systems [fixed size blocks of physical memory], the
'Working Set' is measured relative to the number of pages that a
given application has to have in memory to achieve its proper
performance.  Usually, a certain amount of 'steady-state' paging was
acceptable. However, OS/2 is not a 'Paging System', it is a 'Swapping
System' (variable sized blocks of physical memory).  In contrast to
paging, any mount of 'steady-state' swapping is not acceptable.  This
was proven in the case of Communication Manager, a part of OS/2 EE,
where to achieve the desired performance, there could be no 'steady
state' swapping.  So, in this case, 'Working Set' is all of that
memory which is used by an application during the period of interest.

      The 'Working Set' of an OS/2 program in a given scenario is
defined as:
1.  All the OS/2 Memory Segments (which are a part of that program or
allocated by the program) which are not swappable nor discardable;
e.g., fixed in memory.
2.  All the OS/2 Memory Segments (which are a p...