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.
     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 *              Reserved for future IBM use
    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.
              0000008C       DSIENTCT       140 Number of entries in Cluster
                                            Allocation Table
    0048   72 Dbl-Word     8 DSIENTRY (140) Space for Cluster Allocation
                                            Table
              00000460       DSIENTSZ       *-DSIENTRY SIZE OF CLUSTER
                                            ALLOCATION TABLE
    04A8 1192 Dbl-Word     8 * (0)          Force boundary alignment for
                                            CCW's
    04A8 1192 Unknown      8 DSICHPGM (874) Space For Hard Abend Dump Channel
                                            Program
              00001B50       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
    04A8 1192 Dbl-Word     8 DSICCW         CCW construction area
    04B0 1200 Dbl-Word     8 DSICCWNX (0)   Start of next CCW

#### DSIBK Storage Layout

    *** DSIBK - Dump Space Information Area
    *
    *     +-------------------------------------------------------+
    *   0 |                                                       |
    *     =                       DSILOCK                         =
    *     |                                                       |
    *     +---------------------------+---------------------------+
    *  18 |///////////////////////////|         DSITAPGS          |
    *     +---------------------------+---------------------------+
    *  20 |         DSIDPAHI          |         DSIRSASV          |
    *     +---------------------------+------+--------------------+
    *  28 |         DSIDPALO          |:FLAG |////////////////////|
    *     +---------------------------+------+--------------------+
    *  30 |                                                       |
    *     =                       DSICALBK                        =
    *     |                                                       |
    *     +-------------------------------------------------------+
    *  48 |                                                       |
    *     =                       DSIENTRY                        =
    *     |                                                       |
    *     +-------------------------------------------------------+
    * 4A8 |                                                       |
    *     =                       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
    *
    *     +-------------------------------------------------------+
    * 4A8 |                        DSICCW                         |
    *     +-------------------------------------------------------+
    *
    *** Overlay for DSICHPGM in DSIBK

#### DSIBK Cross Reference

    Symbol         Dspl Value
    -------------- ---- -----
    DSIASA         0048
    DSIBSIZE       04A8 00001FF8
    DSICALBK       0030
    DSICC          0048
    DSICCW         04A8
    DSICCWNX       04B0
    DSICHPGM       04A8
    DSICHPSZ       04A8 00001B50
    DSIDPAHI       0020
    DSIDPALO       0028
    DSIENTCT       0030 0000008C
    DSIENTRY       0048
    DSIENTSZ       0048 00000460
    DSIFLAG        002C
    DSILOCK        0000
    DSINEXT        0050
    DSINPGS        004C
    DSIP           004A
    DSIRSASV       0024
    DSISIZE        04A8 000003FF
    DSITAPGS       001C
    DSIV           004B

This information is based on z/VM V5R2.0. Last updated on 12 Apr 2006 at 16:51:50 EDT.
Copyright IBM Corporation, 1990, 2005