PGAUX Back to Index page
Control Block Contents 
Storage Layout 
Cross Reference (Contains links to field and bit definitions)
Programming Interface Information:
This information is NOT intended to be
used as Programming Interfaces of z/VM.

  PGAUX Prolog Top of page
 NAME       : PGAUX
 DESCRIPTION: Page Auxiliary Status Table Entry
 FUNCTION   : Auxiliary extension of the PGSTE
 LOCATED BY : PGMGPAUX  Field of HCPPGMBK + PTE offset / 2
              A page auxiliary status table resides in a
              page management block associated with a megabyte
              of virtual storage and is addressed by label
              PGMGPAUX.  There are 256 contiguous page auxiliary
              status table entries (PGAUXs) contained in the
              Any specific aux table entry can be obtained by
              extracting the page index from a virtual address,
              multiplying it by the length of an aux entry, and
              adding this offset to the start of the page status
              table.  Also, using the address of a PAGTE as the
              address of a VPGBK, the corresponding PGAUX can be
              found by calculating the offset of the PTE from the
              page table origin, dividing by two, and adding the
              resulting word offset to the start of the page
              auxiliary status table.
 CREATED BY : A page status aux table is imbedded in a page
              management block.  Consequently, space is created
              for it when the PGMBK is created.
              A page status aux table is deleted when a page
              management block is released.
              Serialized by PTE/PGSTE serialization, either
              Shortterm or PCLONLY.
  PGAUX Control Block Content Top of page

 PGAUX DSECT Top of page
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure PGAUX Page Auxiliary Status Table Entry 0000 0 Signed 4 PGAUXENT (0) Aux entry 0000 0 Signed 2 * Reserved for IBM use 0002 2 Signed 2 PGAOVFLW Overflow pin count Count of the number of 128 pin- count overflow increments. Each increment of ASAOVFLW represents 128 pins. The pin count for a page is kept in PGSPINCT, which is only 1 byte in length and can hold up to 127 pin increments. If that overflows, ASAOVFLW is incremented and therefore represents 128 pins. Note that ASAOVFLW can be changed with PCLONLY page serialization by those tasks that are allowed to use PCLONLY.
  PGAUX Storage Layout Top of page
*** PGAUX - Page Auxiliary Status Table Entry
*     +-------------+-------------+
*   0 |/////////////|  PGAOVFLW   | 4
*     +-------------+-------------+
*** PGAUX - Page Auxiliary Status Table Entry
  PGAUX Cross Reference Top of page
Symbol         Dspl Value
-------------- ---- -----
PGAOVFLW       0002
PGAUXENT       0000
This information is based on z/VM 6.3.0 Last updated on 22 May 2013 at 13:56:22 EDT.
Copyright IBM Corporation, 1990, 2013