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Programming Interface Information:
This information is NOT
intended to be
used as Programming Interfaces of VM/ESA. It is to be used for diagnosis only. |
STOBK
Cross Reference (Contains links to field and bit definitions)
STOBK Prolog
Name : DMSSTOBK Description: Storage descriptor block DSECT : STOBK Function : Mapping macro which maps allocated and unallocated storage. There is a STOBK for every page of storage within the virtual machine.
STOBK Control Block Content
STOBK DSECT
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure STOBK Storage descriptor block 0000 0 Signed 4 STOFORWD Forward pointer for chaining STOBKs 0004 4 Signed 4 STOBACKW Backward pointer for chaining STOBKs NOTES : STOKEY and STOFLAG are often moved as a pair. This means that they must NEVER be seperated. 0008 8 Signed 2 STOKFMOV (0) For combined move of STOKEY and STOFLAG 0008 8 Bitstring 1 STOKEY Storage key for the described page 0009 9 Bitstring 1 STOFLAG Flags to define the described page 1... .... STOPAGE1 X'80' First STOBK on a block of STOBKs .1.. .... STOBLOK1 X'40' First STOBK anchored on a SUBBK chain ...1 .... STOFLPT X'10' Page is a full-partial (only valid when STOPART flag is on) .... 1... STORELPG X'08' Page has not been released to CP via DIAG X'10' .... .1.. STOINTRN X'04' Page is internal CMS Storage .... ..1. STOFULL X'02' Page is fully allocated .... ...1 STOPART X'01' Page is partially allocated 000A 10 Signed 2 STOLARGE Size of the largest free piece in a page 000C 12 Signed 4 STOFREEB (0) Anchor to the free pieces in a page 000C 12 Signed 4 STOFIRST (0) Pointer to the first STOBK on a block 000C 12 Signed 4 STONUMBL Number of pages on a block 0010 16 Signed 4 STOSUBAD Pointer to the SUBBK for this STOBK 0014 20 Signed 4 * IBM Reserved 00000018 STOSIZEB *-STOBK Size of a STOBK in bytes 00000003 STOSIZED (STOSIZEB+7)/8 Size of a STOBK in D-words
STOBK Storage Layout
*** STOBK - Storage descriptor block * * +---------------------------+---------------------------+ * 0 | STOFORWD | STOBACKW | * +------+------+-------------+---------------------------+ * 8 |STOKEY|:FLAG | STOLARGE | STONUMBL | * +------+------+-------------+---------------------------+ * 10 | STOSUBAD |///////////////////////////| * +---------------------------+---------------------------+ * 18 * *** STOBK - Storage descriptor block
STOBK Cross Reference
(contains links to field and bit definitions)Symbol Dspl Value -------------- ---- -----STOBACKW 0004
STOBLOK1 0009 40
STOFIRST 000C
STOFLAG 0009
STOFLPT 0009 10
STOFORWD 0000
STOFREEB 000C
STOFULL 0009 02
STOINTRN 0009 04
STOKEY 0008
STOKFMOV 0008
STOLARGE 000A
STONUMBL 000C
STOPAGE1 0009 80
STOPART 0009 01
STORELPG 0009 08
STOSIZEB 0014 00000018
STOSIZED 0014 00000003
STOSUBAD 0010
Last updated on 12 Aug 1999 at 11:13:47 EDT.
Copyright IBM Corporation, 1990, 1999