PPDBK Back to Index page
 
Prolog 
Control Block Contents 
   PPDBK 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.


  PPDBK Prolog Top of page
 
 NAME       : HCPPPDBK
 DESCRIPTION: Paged PGMBK Data block
 DSECT      : PPDBK
 FUNCTION   : A PPDBK contains information required to find
              and process an STE corresponding to a paged
              PGMBK (PTRM page) which has been paged to DASD.
 LOCATED BY : The PPDBK address is saved in the invalid PTRM PTE
              for PTRM pages (paged PGMBKs) that reside on DASD.
              The address is saved in a hashed format so that the
              Invalid and Page Protect bits of the PTRM PTE are
              left undisturbed; HCPISTEA macro is used to insert
              the PPDBK address into the PTRM PTE, HCPGSTEA macro
              is used to extract the PPDBK address from the PTRM
              PTE.
 CREATED BY : HCPHRPOP when a PTRM page is invalidated,
              in preparation for the PTRM page (pageable PGMBK)
              potentially being paged to DASD.
              HCPPMPRB when a PTRM page (paged PGMBK) is
              migrated from expanded storage to DASD.
              HCPHRUSM when processing a segment table
              relocation, and a PTRM page (pageable PGMBK) on
              DASD, but without a PPDBK address in the PTRM PTE,
              is encountered.
 DELETED BY : HCPHTUPF when a PTRM page (paged PGMBK)
              is read in from DASD.
              HCPPTAQA when a PTRM page (pageable PGMBK) is paged
              to expanded storage instead of DASD.
 SERIALIZED :
              Serialized by PTRM PTE serialization, though to use
              or change the PPDSTE field, (at least) a share of
              VMDPTIL on the virtual configuration that owns
              the corresponding segment table entry is required,
              to serialize against concurrent destructive changes
              to the segment table (such as segment table relocate
              for resize during NSS/DCSS imbed/unimbed).
 COMMENTS   :
 
 
  PPDBK Control Block Content Top of page
 

 PPDBK DSECT Top of page
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure PPDBK Paged PGMBK Data block 0000 0 Address 8 PPDSTE Address of STE corresponding to paged PGMBK 0008 8 Address 4 PPDVMDBK Address of the owning vconfig's base VMDBK 0000000C PPDBKLEN *-PPDBK Size of one PPDBK in bytes 00000002 PPDBKSIZ ((*-PPDBK)+7)/8 Size of one PPDBK in dws End of PPDBK definitions
 
 
  PPDBK Storage Layout Top of page
 
          
*** PPDBK - Paged PGMBK Data block
*
*     +-------------------------------------------------------+
*   0 |                        PPDSTE                         |
*     +---------------------------+---------------------------+
*   8 |         PPDVMDBK          | C
*     +---------------------------+
*
*** PPDBK - Paged PGMBK Data block
 
 
  PPDBK Cross Reference Top of page
 
 
Symbol         Dspl Value
-------------- ---- -----
PPDBKLEN       0008 0000000C
PPDBKSIZ       0008 00000002
PPDSTE         0000
PPDVMDBK       0008
 
This information is based on z/VM 7.2.0 Last updated on 24 Jun 2020 at 09:29:42 EDT.
Copyright IBM Corporation, 1990, 2020