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Programming Interface Information:
This information is NOT intended to be used as Programming Interfaces of z/VM. |
SUBBK
Control Block Contents
SUBBK DSECT
Cross Reference (Contains links to field and bit definitions)
SUBBK Prolog
NAME : HCPSUBBK
DESCRIPTION: Subpool Data Area Block
DSECT : SUBBK
FUNCTION :
Maps each of the free storage subpool data area
elements.
CREATED BY : Never allocated
DELETED BY : Never deallocated
RELOCATION CONSIDERATIONS : None
NOTES : This DSECT is used to map the free storage subpool
data area groups located in HCPRSM, specifically,
HCPRSMSS (regular free storage subpools).
Each data area group consists of multiple data
area elements.
SUBBK Control Block Content
SUBBK DSECT
Hex Dec Type/Val Lng Label (dup) Comments
---- ---- --------- ---- -------------- --------
0000 0 Structure SUBBK Subpool Data Area Block
Format 0 ("old style") SUBBK format used for subpools for
the following types of subpooled free storage:
- Virtual Free Storage (HCPVFM)
- Host Logical Aligned Free Storage (HCPAFS)
- Verifiable Free Storage (HCPVCB)
0000 0 Signed 4 SUBLOCK Subpool lock word
0004 4 Signed 4 SUBSIZE Integral size (in DWDS) of
subpool block including FRERECL
0008 8 Address 8 SUBANCHG Pointer to 1st SXSTE for
subpooled free storage.
0010 16 Signed 4 SUBODWD Count of DWD currently in use
(multiple of SUBSIZE)
0014 20 Signed 4 SUBCDWD Count of DWDS now on chain
0018 24 Signed 4 SUBUDWD Count of actual DWD usage (does
not include internal
fragmentation)
001C 28 Signed 4 SUBRCNT Count of requests this size
0020 32 Signed 4 * Reserved for IBM use
0024 36 Signed 4 * Reserved for IBM use
0028 40 Signed 4 * Reserved for IBM use
002C 44 Signed 4 * Reserved for IBM use
0030 48 Signed 4 * Reserved for IBM use
0034 52 Signed 4 * Keep total length in whole
numbers of dwords
00000038 SUBESZ *-SUBBK Size of one subpool entry
Format 1 ("new/fast style") SUBBK format used for standard
short term free storage, including "fast allocated" free
storage control blocks.
0000 0 Bitstring 1 SUBTSLK Subpool lock byte
0001 1 Bitstring 1 * Reserved for IBM use
0002 2 Signed 2 SUBBSIZE Size in bytes (including
header/trailer) of each block on
this subpool
0004 4 Signed 2 SUBMAXBS Maximum number of blocks that fit
in one page
0006 6 Signed 2 * Reserved for IBM use Notes : The
following three fields (SUBFRETS,
SUBBLOCK, and SUBTOTRQ) must
remain contiguous and in order,
as there is performance sensitive
code in the free storage
allocation and deallocation paths
which references two adjacent
fields (SUBBLOCK and SUBTOTRQ for
allocation, SUBFRETS and SUBBLOCK
for deallocation) with a single
STM instruction
0008 8 Signed 4 SUBFRETS Total count of returns to this
free storage subpool
000C 12 Signed 4 SUBBLOCK Anchor for blocks on this subpool
0010 16 Signed 4 SUBTOTRQ Total count of requests against
this subpool
0014 20 Signed 4 SUBCLCTP Collection pile
0018 24 Address 8 SUBMTFTEG SXSTE address of 1st empty page
on queue. FFS mark end of chain.
0020 32 Signed 4 SUBXTNCT Count of extends
0024 36 Signed 4 SUBPAGCT Count of pages on pool
0028 40 Signed 4 SUBINUSE Count of blocks in use on this
subpool
002C 44 Signed 4 SUBMTFCT Count of pages on SUBMTFTE empty
page queue for this subpool
0030 48 Signed 4 SUBBLKCT Total count of available blocks
on SUBBLOCK queue + the SUBCLCTP
(collection pile) queue. RAS
count maintained only in debug
mode. Combined count enables
accuracy during HCPFRFDX
processing which requeues the
blocks.
0034 52 Signed 4 * Reserved for IBM use
00000038 SUBNEXT * Address of next SUBBK
00000038 SUBSSZ *-SUBBK Size of one standard
short term free storage SUBBK
entry
00000002 SUBOFFSH 2 Number of bits to shift a
subpool number to get the index
into the HCPFRESO SUBBK offsets
table for the subpool's SUBBK
Format 2 SUBBK format used for real aligned free storage
0000 0 Signed 4 SUB2LOCK Subpool lock word
0004 4 Signed 4 SUB2SIZE Integral size (in DWDS) of
subpool block including FRERECL
0008 8 Address 8 SUB2ANCH Pointer to 1st FRMTE for
subpooled free storage.
0010 16 Dbl-Word 8 SUB2ODWD Count of DWD currently in use
(multiple of SUBSIZE)
0018 24 Dbl-Word 8 SUB2CDWD Count of DWDS now on chain
0020 32 Dbl-Word 8 SUB2UDWD Count of actual DWD usage (does
not include internal
fragmentation)
0028 40 Signed 4 SUB2RCNT Count of requests this size
002C 44 Signed 4 * Reserved for IBM use
0030 48 Signed 4 * Reserved for IBM use
0034 52 Signed 4 * Keep total length in whole
numbers of dwords
00000038 SUBASZ *-SUBBK Size of one subpool entry
SUBBK Storage Layout
*** SUBBK - Subpool Data Area Block
*
* +---------------------------+---------------------------+
* 0 | SUBLOCK | SUBSIZE |
* +---------------------------+---------------------------+
* 8 | SUBANCHG |
* +---------------------------+---------------------------+
* 10 | SUBODWD | SUBCDWD |
* +---------------------------+---------------------------+
* 18 | SUBUDWD | SUBRCNT |
* +---------------------------+---------------------------+
* 20 |///////////////////////////|///////////////////////////|
* +---------------------------+---------------------------+
* 28 |///////////////////////////|///////////////////////////|
* +---------------------------+---------------------------+
* 30 |///////////////////////////|///////////////////////////|
* +---------------------------+---------------------------+
* 38
*
*** SUBBK - Subpool Data Area Block
*** Overlay for SUBLOCK in SUBBK
*
* +------+------+-------------+-------------+-------------+
* 0 |:TSLK |//////| SUBBSIZE | SUBMAXBS |/////////////|
* +------+------+-------------+-------------+-------------+
* 8 | SUBFRETS | SUBBLOCK |
* +---------------------------+---------------------------+
* 10 | SUBTOTRQ | SUBCLCTP |
* +---------------------------+---------------------------+
* 18 | SUBMTFTEG |
* +---------------------------+---------------------------+
* 20 | SUBXTNCT | SUBPAGCT |
* +---------------------------+---------------------------+
* 28 | SUBINUSE | SUBMTFCT |
* +---------------------------+---------------------------+
* 30 | SUBBLKCT |///////////////////////////|
* +---------------------------+---------------------------+
* 38
*
*** Overlay for SUBLOCK in SUBBK
*** Overlay for SUBLOCK in SUBBK
*
* +---------------------------+---------------------------+
* 0 | SUB2LOCK | SUB2SIZE |
* +---------------------------+---------------------------+
* 8 | SUB2ANCH |
* +-------------------------------------------------------+
* 10 | SUB2ODWD |
* +-------------------------------------------------------+
* 18 | SUB2CDWD |
* +-------------------------------------------------------+
* 20 | SUB2UDWD |
* +---------------------------+---------------------------+
* 28 | SUB2RCNT |///////////////////////////|
* +---------------------------+---------------------------+
* 30 |///////////////////////////|///////////////////////////|
* +---------------------------+---------------------------+
* 38
*
*** Overlay for SUBLOCK in SUBBK
SUBBK Cross Reference
Symbol Dspl Value -------------- ---- ----- SUBANCHG 0008 SUBASZ 0034 00000038 SUBBLKCT 0030 SUBBLOCK 000C SUBBSIZE 0002 SUBCDWD 0014 SUBCLCTP 0014 SUBESZ 0034 00000038 SUBFRETS 0008 SUBINUSE 0028 SUBLOCK 0000 SUBMAXBS 0004 SUBMTFCT 002C SUBMTFTEG 0018 SUBNEXT 0034 00000038 SUBODWD 0010 SUBOFFSH 0034 00000002 SUBPAGCT 0024 SUBRCNT 001C SUBSIZE 0004 SUBSSZ 0034 00000038 SUBTOTRQ 0010 SUBTSLK 0000 SUBUDWD 0018 SUBXTNCT 0020 SUB2ANCH 0008 SUB2CDWD 0018 SUB2LOCK 0000 SUB2ODWD 0010 SUB2RCNT 0028 SUB2SIZE 0004 SUB2UDWD 0020
Copyright IBM Corporation, 1990, 2011