XSUBK Back to Index page
 
Prolog 
Control Block Contents 
   XSUBK DSECT
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.


  XSUBK Prolog Top of page
  
 NAME       : HCPXSUBK
 DESCRIPTION: Expanded Storage Usability Map
 DSECT      : XSUBK
 FUNCTION   : This map is used to keep track of the allocation
              of Expanded Storage. Each map corresponds to one
              increment of XSTORE and can therefore represent
              up to 64Meg of expanded storage.
 LOCATED BY : XDRUMAPT located in the HCPXDRBK.
 CREATED BY : HCPESCDI during initialization processing.
 DELETED BY : HCPESCDI if no expanded storage is configured
              to the system.
 RELOCATION CONSIDERATIONS : None
 
 
  XSUBK Control Block Content Top of page
  




 XSUBK DSECT
Top of page


Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      XSUBK          Expanded Storage Usability Map
             The following are bit maps that represents the
             allocation of one increment of Expanded Storage
             (up to 64 megabytes).
             Each bit position represents the allocation state
             of a block of XSTORE.
0000    0 Bitstring    1 XSUALMAP (2048)
                                        XSTORE availability map. When a
                                        bit's value is "1" then the
                                        corresponding block is allocated.
0800 2048 Bitstring    1 XSUERMAP (2048)
                                        XSTORE error map. When a bit's
                                        value is "1" then the
                                        corresponding block is in error.
 
 
  XSUBK Storage Layout Top of page
  
          
*** XSUBK - Expanded Storage Usability Map
*
*     +-------------------------------------------------------+
*   0 |                                                       |
*     =                       XSUALMAP                        =
*     |                                                       |
*     +-------------------------------------------------------+
* 800 |                                                       |
*     =                       XSUERMAP                        =
*     |                                                       |
*     +-------------------------------------------------------+
*1000
*
*** XSUBK - Expanded Storage Usability Map
 
 
  XSUBK Cross Reference Top of page
  
 
Symbol         Dspl Value
-------------- ---- -----
XSUALMAP       0000
XSUERMAP       0800
 
This information is based on z/VM 7.2.0 Last updated on 24 Jun 2020 at 09:31:52 EDT.
Copyright IBM Corporation, 1990, 2020