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Programming Interface Information:
This information is NOT intended to be
used as Programming Interfaces of z/VM. |
CAABK
Control Block Contents
CAABK DSECT
Cross Reference (Contains links to field and bit definitions)
CAABK Prolog
NAME : HCPCAABK
DESCRIPTION: CP-use Address space Allocation block
DSECT : CAABK
FUNCTION : Allocation of virtual addresses in CP-use
address spaces
LOCATED BY : ASCTYPTR field of ASCBK
CREATED BY : Creation of a HCPVAM-managed address space, either
by HCPASMCR or its callers.
DELETED BY : Never deleted.
SERIALIZED :
All fields except reorganization fields serialized
by CAALOCK held exclusive. ASCLOCK in the ASCBK for
this address space must be held shared when obtain-
CAALOCK. If ASCLOCK is held exclusive, CAALOCK need
not be held.
CAABK Control Block Content
CAABK DSECT
Hex Dec Type/Val Lng Label (dup) Comments
---- ---- --------- ---- -------------- --------
0000 0 Structure CAABK CP-use Address space Allocation
block
0000 0 Address 4 CAAAVAIL Anchor of a chain of PGMBK
FRMTE(s) containing all
deallocated PTEs below the
address space's high water mark
(CAAHIWTR). The PGMBK FRMTE(s) on
this chain are sorted in
ascending virtual address order.
A CAAAVAIL of zeros indicates an
empty chain. This chain is ended
by a fullword of zeros in
FRMFPNT. Hold CAALOCK or ASCLOCK
exclusive when updating this
field.
0008 8 Dbl-Word 8 CAAHIWTR Virtual page address
corresponding to the next
available PTE in this CP-use
address space. All pages below
this mark are either currently
allocated or are chained on
CAAAVAIL. CAAHIWTR never points
at an allocated page. No pages
above CAAHIWTR are ever allocated
or chained on CAAAVAIL. Hold
CAALOCK or ASCLOCK exclusive when
updating this field.
0008 8 Signed 4 CAAHIWTRH High half of virtual address
000C 12 Signed 4 CAAHIWTRL Low half of virtual address
0010 16 Signed 4 CAAFPTE Count of PTEs in this CP-use
address space that exist but do
not currently hold an allocated
page. This number is an
indication of the amount of host
real storage currently allocated
to map this CP-use address space,
but is not being used. This
number can therefore be used to
determine when it would be
beneficial to reorganize the
address space. Hold CAALOCK or
ASCLOCK exclusive when updating
this field.
0014 20 Signed 4 CAAUSTE Count of used segment table
entries in this CP-use address
space. Hold CAALOCK or or ASCLOCK
exclusive when updating this
field.
0018 24 Signed 4 CAALOCK CP-use address space allocation
lock. This is an informal spin
lock. Must be held when updating
certain CAABK fields (see above).
ASCLOCK must be held shared to
obtain this lock. If ASCLOCK is
held exclusive, there is no need
to obtain this lock.
001C 28 Signed 4 CAAROGCT Number of times this address
space has been reorganized. Hold
CAAROGLK when updating this
field.
0020 32 Dbl-Word 8 CAAREORG Time of day last reorganization
occured for this address space.
Hold CAAROGLK when updating this
field.
0028 40 Bitstring 1 CAAROGLK Address space reorganization test
and set (TS) lock.
0029 41 Bitstring 1 * (3) Reserved for future IBM use
002C 44 Signed 4 * (3) Reserved for future IBM use
0038 56 Signed 4 CAAFSI (0) Function-specific information
section
00000007 CAASIZE (*-CAABK+7)/8 Size, in
doublewords, of CAABK.
CAABK Storage Layout
*** CAABK - CP-use Address space Allocation block
*
* +---------------------------+---------------------------+
* 0 | CAAAVAIL |///////////////////////////|
* +---------------------------+---------------------------+
* 8 | CAAHIWTR |
* +-------------------------------------------------------+
* 10
*
*** CAABK - CP-use Address space Allocation block
*** Overlay for CAAHIWTR in CAABK
*
* +---------------------------+---------------------------+
* 8 | CAAHIWTRH | CAAHIWTRL |
* +---------------------------+---------------------------+
* 10 | CAAFPTE | CAAUSTE |
* +---------------------------+---------------------------+
* 18 | CAALOCK | CAAROGCT |
* +---------------------------+---------------------------+
* 20 | CAAREORG |
* +------+--------------------+---------------------------+
* 28 |:ROGLK|////////////////////|///////////////////////////|
* +------+--------------------+///////////////////////////|
* |///////////////////////////////////////////////////////|
* +-------------------------------------------------------+
*
*** Overlay for CAAHIWTR in CAABK
CAABK Cross Reference
Symbol Dspl Value -------------- ---- ----- CAAAVAIL 0000 CAAFPTE 0010 CAAFSI 0038 CAAHIWTR 0008 CAAHIWTRH 0008 CAAHIWTRL 000C CAALOCK 0018 CAAREORG 0020 CAAROGCT 001C CAAROGLK 0028 CAASIZE 0038 00000007 CAAUSTE 0014
Last updated on 5 Jun 2001 at 13:00:54 EDT.
Copyright IBM Corporation, 1990, 2001