HP OpenVMS Systems

Virtual Memory and Working Set?

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The Question is:

 
What is the meaning of Working set?
 
In the authorize utility we can see the following parameters,
 WSdef,WSquo,WSextend...I know all of them are related to Working set..
 
Thanks in Advance.
 
 
 

The Answer is :

 
  This question is central to the implementation of virtual memory on
  OpenVMS -- for details on virtual memory, please see the OpenVMS
  Internals and Data Structures Manual (IDSM).
 
  The process working set is that portion of the process virtual address
  space that is currently residing in system physical memory.  Other
  portions of process virtual address space may not be instantiated, or
  may currently be residing in backing storage (eg: pagefile).
 
  The initial size of the working set is established by the WSDEFAULT quota,
  the guaranteed size is determined by the WSQUOTA quota, and -- when
  sufficient system free memory is available -- it can grow to the value
  of the WSEXTENT quota.
 
  The act of transfering the contents of a page of memory from backing
  storage, from the free memory pool, or from a cache of modified pages
  into the process working set is known as a page fault -- the general
  process is known as paging.  Paging is normally transparent to the
  application.
 

  

     

     
answer written or last revised on ( 22-OCT-2001 )
     
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