Programming Interface Information:
This information is NOT intended to be
used as Programming Interfaces of z/VM.

DSIBK

Prolog  

Control Block Contents  
   DSIBK DSECT

Storage Layout  

Cross Reference (Contains links to field and bit definitions)  


DSIBK Prolog

 NAME       : HCPDSIBK
 DESCRIPTION: Dump Space Information Area
 DSECT      : DSIBK
 FUNCTION   : The DSIBK resides in host permanent storage and is
              used to contain the dump space allocation CALBK,
              size information and the channel program construction
              area for CP system abend dump processing
 LOCATED BY : SYSDSIBK IN HCPSYSCM
 CREATED BY : SYSTEM DEFINITION
 DELETED BY : NOT DELETED
 SERIALIZED : The Dump Space Allocation Lock contained
              within this data area.
 RELOCATION CONSIDERATIONS : None
 COMMENTS   : DSIDPALO and DSIDPAHI are threshold values used
              to communicate to the storage management.  If
              RSADPACP is larger than DSIDPAHI then it is
              time to get more dump space.  If RSADPACP is
              smaller than DSIDPALO then it is time to
              release and reallocate the dump space.

 

DSIBK Control Block Content


DSIBK DSECT

Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      DSIBK          Dump Space Information Area
0000    0 Dbl-Word     8 DSILOCK (3)    Dump Space Allocation Lock
      The following fields are for additional cluster allocation, when
       needed.
0018   24 Signed       4 DSIOLDHI       Previous Hi Threshold.
001C   28 Signed       4 DSITAPGS       Total DASD pages currently
                                        allocated
0020   32 Signed       4 DSIDPAHI       High Threshold value for CP-owned
                                        pages. When the value in this
                                        field is X'FFFFFFFF' no
                                        additional DASD dump space is to
                                        be obtained.
0024   36 Signed       4 DSIRSASV       RSADPACP at time of reallocation
0028   40 Signed       4 DSIDPALO       Low Threshold value for CP-owned
                                        pages. When the value in this
                                        field is X'FFFFFFFF', extra DASD
                                        dump is not released
002C   44 Signed       4 * (0)
002C   44 Bitstring    1 DSIFLAG        Test and set flag which indicates
                                        that a call to allocate
                                        additional DASD dump space has
                                        been stacked.
002D   45 Bitstring    3 *              RESERVED FOR FUTURE IBM USE
0030   48 Bitstring   24 DSICALBK       CALBK header entry size
         This area contains the CALBK for the dump space allocation
         function. It is required when managing clusters of DASD dump
         space and is needed as input to HCPPGCAL and HCPPGCRL, the
         cluster allocation and release entry points, respectively.
      The number of entries in the cluster allocation table is
      based on experience.  As the size of the average dump
      increases in subsequent releases, customers may encounter
      message HCP9255I more frequently and the value for
      DSIENTCT may need to be increased.  Consequently, the
      size of the entire DSIBK may need to be increased beyond
      2 pages in order to provide space to build an effective
      channel program.
      Using 495 cause DSICHPGM to be x'FC0' which probably won't
      cause any problems for HCPDMP which builds the channel pgm.
          000001EF       DSIENTCT       495 Number of entries in CALBK
0048   72 Dbl-Word     8 DSIENTRY (495) Space for Cluster Allocation
                                        Table
          00000F78       DSIENTSZ       *-DSIENTRY SIZE OF CLUSTER
                                        ALLOCATION TABLE
0FC0 4032 Dbl-Word     8 * (0)          Force boundary alignment for
                                        CCW's
0FC0 4032 Unknown      8 DSICHPGM (519) Space For Hard Abend Dump Channel
                                        Program
          00001038       DSICHPSZ       *-DSICHPGM SIZE OF CHANNEL
                                        PROGRAM AREA
          000003FF       DSISIZE        (*-DSIBK+7)/8 DSIBK ENTRY SIZE IN
                                        DOUBLEWORDS
          00001FF8       DSIBSIZE       DSISIZE*8 DSIBK ENTRY SIZE IN
                                        BYTES
      OVERLAY FOR ACCESSING THE NEXT ASA FOR Space INFORMATION
0048   72 Signed       4 DSIASA (0)     ASA for start of allocation
0048   72 Bitstring    2 DSICC          If CKD or ECKD, cylinder part
004A   74 Bitstring    1 DSIP           If CKD or ECKD, page part
004B   75 Bitstring    1 DSIV           volume part of DSIASA
004C   76 Signed       4 DSINPGS        NUMBER OF Pages ALLOCATED
0050   80 Signed       4 DSINEXT (0)    Start of the next ASA entry
0FC0 4032 Dbl-Word     8 DSICCW         CCW construction area
0FC8 4040 Dbl-Word     8 DSICCWNX (0)   Start of next CCW

 

DSIBK Storage Layout

          
*** DSIBK - Dump Space Information Area
*
*     +-------------------------------------------------------+
*   0 |                                                       |
*     =                       DSILOCK                         =
*     |                                                       |
*     +---------------------------+---------------------------+
*  18 |         DSIOLDHI          |         DSITAPGS          |
*     +---------------------------+---------------------------+
*  20 |         DSIDPAHI          |         DSIRSASV          |
*     +---------------------------+------+--------------------+
*  28 |         DSIDPALO          |:FLAG |////////////////////|
*     +---------------------------+------+--------------------+
*  30 |                                                       |
*     =                       DSICALBK                        =
*     |                                                       |
*     +-------------------------------------------------------+
*  48 |                                                       |
*     =                       DSIENTRY                        =
*     |                                                       |
*     +-------------------------------------------------------+
* FC0 |                                                       |
*     =                       DSICHPGM                        =
*     |                                                       |
*     +-------------------------------------------------------+
*1FF8
*
*** DSIBK - Dump Space Information Area
          
*** Overlay for DSIENTRY in DSIBK
*
*     +-------------+------+------+---------------------------+
*  48 |   DSICC     |DSIP  |DSIV  |         DSINPGS           |
*     +-------------+------+------+---------------------------+
*
*** Overlay for DSIENTRY in DSIBK
          
*** Overlay for DSICHPGM in DSIBK
*
*     +-------------------------------------------------------+
* FC0 |                        DSICCW                         |
*     +-------------------------------------------------------+
*
*** Overlay for DSICHPGM in DSIBK

 

DSIBK Cross Reference

Symbol         Dspl Value
-------------- ---- -----
DSIASA         0048
DSIBSIZE       0FC0 00001FF8
DSICALBK       0030
DSICC          0048
DSICCW         0FC0
DSICCWNX       0FC8
DSICHPGM       0FC0
DSICHPSZ       0FC0 00001038
DSIDPAHI       0020
DSIDPALO       0028
DSIENTCT       0030 000001EF
DSIENTRY       0048
DSIENTSZ       0048 00000F78
DSIFLAG        002C
DSILOCK        0000
DSINEXT        0050
DSINPGS        004C
DSIOLDHI       0018
DSIP           004A
DSIRSASV       0024
DSISIZE        0FC0 000003FF
DSITAPGS       001C
DSIV           004B

This information is based on z/VM V6R2.0. Last updated on 21 Nov 2011 at 11:00:25 EDT.
Copyright IBM Corporation, 1990, 2011