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Programming Interface Information:
This information is NOT intended to be
used as Programming Interfaces of z/VM. |
XSTMG
Control Block Contents
XSTMG DSECT
Cross Reference (Contains links to field and bit definitions)
XSTMG Prolog
Name : HCPXSTMG
Description: Expanded storage management data
DSECT : XSTMG
Function : This block is used to keep track of global
Information associated with the expanded
Storage facility and block paging.
Located by : This DSECT overlays the data Entry Point
HCPPGDXT.
Created by : HCPPGD is loaded by the system during IPL.
The XSTMG is initialized by HCPESCDI.
Deleted by : never deleted.
XSTMG Control Block Content
XSTMG DSECT
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure XSTMG Expanded storage management data 0000 0 Signed 4 XSTMGSTR (0) Start of XSTMG block 0000 0 Signed 4 XSTFLAGS (0) Flags for the XSTMG block. Updated with compare and swap. 0000 0 Address 1 XSTSTAFG Status information flag .... ...1 XSTNCONF X'01' Xstore is not configured to the system. .... ...1 XSTOFFLN X'01' Xstore was taken offline because all blocks are in error. .... ..1. XSTMPDSB X'02' Xstore has been disabled for CP paging temporarily until at least one increment can be brought online during initilization or recovery from a machine check. This bit has no meaning if XSTOFFLN is on. .... .1.. XSTNAVAL X'04' Indicates that there is no XSTORE available for allocation. This may happen if all XSTORE has been attached to a guest or the CP partition has been completely allocated. .... 1... XSTMDALL X'08' Indicates that there is no XSTORE available for paging allocation. The Xstore is to be used only for allocation to Minidisk Cache. ...1 .... XSTEXTMP X'10' If on, indicates that Read Expanded Storage Usability Bit Map Extended is installed. If off, nothing is implied about the existence of other usability map facilities. .1.. .... XSTRREQD X'40' Usability-map repair is required. When this bit is on, work has been stacked to perform the repair action. This bit has no meaning if XSTOFFLN is on. The following are the flags that indicate status. 0001 1 Bitstring 1 XSTFUTCT COUNT OF STAMPS WITH FUTURE TIMES 0002 2 Signed 2 XSTAVGAG Average age of paging XBLKs 0004 4 Signed 4 XSTSTATL XSTORE statistics lock used to serialize updates to : XSTCTXTS, XSTEPOCH, PGMXSTCT, ASCCTXBK, ASCCTXRD, and ASCCTXWT. 0008 8 Signed 4 XSTCTXTS Count of XSTORE blocks currently in use for CP Paging. Used by MIG to calculate average timestamp. Serialized by XSTSTATL. 000C 12 Signed 4 XSTCTXER Number of blocks in error that have not yet been reflected to a guest. Update holding XSTBUFLK. 0010 16 Signed 4 XSTOTALB Amount of XSTORE online in blocks. It represents the number of blocks in "configured" increments. Set at initialization and not changed. 0014 20 Signed 4 XSTGUEST Number of blocks attached to virtual machines including error blocks. To update hold HCPPGDXL. 0018 24 Signed 4 XSTINCRB Number of blocks per XDRBK. 001C 28 Signed 4 XSTCPINC Amount of xstore in blocks that are in the "CP" state and are "Configured". It includes error blocks but excludes CP-Retained blocks. To update hold HCPPGDXL. 0020 32 Signed 4 XSTCPSTR Total number of blocks that are in the cp-retained state including blocks in error. To update hold HCPPGDXL. 0024 36 Signed 4 XSTPEDRT Amount of xstore in blocks that is waiting to be assigned the retained state. This is pending retain. The sum of XSTCPSTR and XSTPEDRT is the amount specified on the last RETAIM XSTORE command. To update hold HCPPGDXL. 0028 40 Signed 4 XSTMSKIP XBLKs skipped by migrator because they were too young 002C 44 Signed 4 XSTALLMB Sum of BLKDM+BLKCY+BLKSH+BLKSY Used in timestamp adjustment The following area is used by XSTORE migration 0030 48 Signed 4 * (0) Migration lock and flag word 0030 48 Bitstring 1 XSTMIGLK TS LOCK BYTE FOR MIGRATION 0031 49 Bitstring 1 XSTMIFLG MIGRATION FLAG BYTE 1... .... XSTMISLP X'80' Migration is awaiting redrive .1.. .... XSTNORML X'40' Normal migration in progress ..1. .... XSTFLUSH X'20' Flush is in progress ...1 .... XSTPTIL X'10' The PTIL lock and the owned ASCBK queue lock (VMDASCLK) are held for the current VMDBK .... 1... XSTDCSS X'08' DCSS scan is in progress .... .1.. XSTNSS X'04' NSS scan is in progress .... 11.. XSTSHARE XSTNSS+XSTDCSS NSS or DCSS scan is in progress .... ..1. XSTRESUM X'02' Migration is restarting after loss of control .... ...1 XSTSHAS X'01' Shared address space scan is in progress .... 11.1 XSTNOCYC XSTNSS+XSTDCSS+XSTSHAS A non-cyclic list (NSS, DCSS, or SHAS) scan is in progress. The following represent bit settings for XSTMIFLG 0032 50 Signed 2 XSTBMULT Used to control number of migrate buffers obtained at migration invocation. (XSTBMULT*paging vols) 0000000F XSTMMAX 15 Highest allowed value for XSBMULT 00000005 XSTMMIN 5 Lowest value allowed for XSTBMULT 0034 52 Address 4 XSTCYCLE The VMDBK address of a user in the Cyclic List that will be the next target of migration. 0038 56 Bitstring 4 XSTFRMAQ MIGRATION FRAME QUEUE (BUFFERS) 003C 60 Signed 4 XSTNUMAQ Number on the migrate frame queue ...1 .... XSTMIBLF 16 Migrate blocking factor - the minimum desirable XSTNUMAQ value to give decent DASD blocking 0040 64 Signed 2 XSTTGTEP Epoch of target time 0042 66 Signed 2 XSTTARGT Target age in seconds 0044 68 Signed 2 XSTEPOCH Current Steal TOD clock epoch Serialized by XSTSTATL. 0046 70 Signed 2 XSTSTIME Migrate/steal timer 0048 72 Signed 4 XSTADJTG When XSTMSKIP hits this value its time to adjust the target age 004C 76 Signed 4 XSTMAXCT Num of times target time lowered 0050 80 Bitstring 1 XSTMIFRM FRAME CODE TO USE ON MIGRATOR BUFFER FRAMES. 0051 81 Bitstring 1 XSTMIFL2 SECOND MIGRATION FLAG BYTE The following represent bit settings for XSTMIFL2 1... .... XSTMINTG X'80' Emergency scan with lowest tgt .1.. .... XSTCYEND X'40' Branched to FLSHDONE from CYCLEND ..1. .... XSTCKGAL X'20' Branched to FLSHDONE from CHKCTGAL ...1 .... XSTFNDDS X'10' Indicate that we noticed a user whose address space(s) were being destroyed while we were attempting to flush XSTORE. .... 1... XSTUSE8K X'08' Using (or waiting for) an 8K buffer. This bit is only set when an 8K buffer is required. If it is ON when buffers are being returned after I/O, it means migration should only restart when 8K buffers are available. .... .1.. XSTNDONE X'04' Normal migration has completed early without reaching the high threshold due to the average age of blocks in expanded storage becoming too low. If flush is active, migration will continue. 0052 82 Signed 2 XSTMINAG Minimum age to allow migration 0054 84 Signed 4 XSTITIME TOD of first steal or tmr wrap 0058 88 Signed 8 XSTSUMAG Sum of ages of migrated blocks 0060 96 Signed 4 XSTUSRDM Number of dormant guest owned address spaces that were the target of migration 0064 100 Signed 4 XSTUSRCY Number of non-dormant guest owned address spaces that were the target of migration 0068 104 Signed 4 XSTUSRSH Number of Named Saved Systems and Saved Segments (DCSSs and Segment Spaces) that were the target of migration 006C 108 Signed 4 XSTCTGAL Count of blocks to flush from the users partition being assigned to the virtual machine given by XSTATVMD. To update hold XSTBUFLK. 0070 112 Signed 4 XSTBLKDM Number of blocks migrated from a dormant guest 0074 116 Signed 4 XSTBLKCY Number of blocks migrated from a non-dormant guest 0078 120 Signed 4 XSTBLKSH Number of blocks migrated from a shared system 007C 124 Signed 4 XSTBLKSY Number of blocks migrated from the CP system 0080 128 Signed 4 XSTQUEND Anchor of current SNT queue 0084 132 Signed 4 XSTMISAQ Number of frames missing (taken) from migration frame queue without being replenished 0088 136 Signed 4 XSTMIFRS Total number of migration buffer frames, including both available (on XSTFRMAQ) and in use frames. 008C 140 Signed 4 XSTMIGS Count of migrate invocations 0090 144 Signed 4 XSTCTPGM Count of PGMBKS selected 0094 148 Bitstring 4 XSTFROUT QUEUE OF FRAMES TO BE WRITTEN 0098 152 Signed 4 XSTLOTHR Low threshold for migration 009C 156 Signed 4 XSTHITHR High threshold for migration 00A0 160 Signed 4 XSTRSTLO XSTLOTHR is raised if XSTLOH20 is smaller than RSTLO at end of mig 00A4 164 Signed 4 XSTRLOCT Number of times buffer increased 00A8 168 Signed 4 XSTRSTHI XSTLOTHR is lowered if XSTLOH20 is larger 3 times in a row at mig end 00AC 172 Signed 4 XSTRHICT Number of times buffer decreased 00B0 176 Signed 4 XSTHICNT Number of times XSTLOH20 was larger than XSTRSTHI 00B4 180 Signed 4 XSTLOH2O Minimum number of XSTORE blocks available during this migration 00B8 184 Signed 4 XSTSKIPA The number of XBLKs we are willing to skip before resetting target 00BC 188 Address 4 XSTCURAS Current (or last) ASCBK being migrated from 00C0 192 Address 4 XSTCURVM Current (or last) VMDBK being migrated from; contains current SNTBK address if XSTNSS or XSTDCSS flag set in XSTMIFLG 00C4 196 Signed 4 XSTSEGCT Count of STLBK SEGTEs processed 00C8 200 Signed 4 XSTDDSAV Save area for XSFDD's R13 while migrator runs. 00CC 204 Signed 4 XSTMDCSA Save area for MDC flush 00D0 208 Address 4 XSTCURSG Segment currently being migrated 00D4 212 Address 4 XSTLSTSG Migratee's final segment 00D8 216 Address 4 XSTDFRAS ASCBK of deferred address space 00DC 220 Bitstring 4 * reserved 00E0 224 Signed 4 XSTNOIO No IO was required for migration 00E4 228 Signed 4 XSTCYCLS Number of times through cyclic 00E8 232 Signed 4 XSTFLCYC Number of cycles while flushing 00EC 236 Signed 4 XSTMRABI Count of pages that were read in as part of a block but not used (as seen by migrate) 00F0 240 Signed 4 XSTSRABI Count of pages that were read in as part of a block but not used (as seen by steal) 00F4 244 Signed 4 XSTSRGCT Single reads for guests 00F8 248 Signed 4 XSTSRSCT Single reads for system 00FC 252 Signed 4 XSTBPRCT Blocks of pages read 0100 256 Address 4 XSTATVMD Address of the VMDBK having XSTORE attached. This is the base VMDBK for the primary configuration for this virtual machine (VMDORIG). to update hold XSTBUFLK and hcppgdxl. 0104 260 Signed 4 XSTATLOW Lowest block number associated with the partition being attached to the virtual machine given in xstatvmd. To update hold xstbuflk and HCPPGDXL. 0108 264 Signed 4 XSTATHI Highest block number associated with the partition being attached to the virtual machine given in XSTATVMD. To update hold XSTBUFLK and HCPPGDXL. 010C 268 Signed 4 XSTATSIZ Amount of configured expanded storage being attached to the virtual machine given in XSTATVMD. To update hold XSTBUFLK and HCPPGDXL. The following area is used for XSTORE block allocation 0110 272 Signed 4 XSTXBZIP Times no XSTORE was available 0114 276 Signed 4 XSTXBGET Number of XSTORE allocations 0118 280 Signed 4 XSTXBREL Number of XSTORE releases 011C 284 Signed 4 XSTMAXK Highest XSTORE increment number 0120 288 Signed 4 XSTINCRM Highest supported hardware increment number after capping 0124 292 Signed 4 * Reserved for IBM use 0128 296 Signed 4 XSTCPPAR Number of blocks in CP partition available for allocation. This is the total number of blocks in the CP and CP-Retained states excluding those in error. To update hold HCPPGDXL. 012C 300 Signed 4 XSTCTXAV Count of available blocks in the CP partition. To update hold XSTBUFLK. 00000130 XSTMGMSZ *-XSTMGSTR Size of monitored portion of XSTMG 0130 304 Signed 4 XSTDIRAN Anchor to the XSTORE directory 0134 308 Signed 4 XSTALCR Allocation cursor: points to the directory entry (XDRBK) where the the last block was allocated. 0138 312 Bitstring 1 XSTBUFLK TS LOCK FOR BAT BUFFER 0139 313 Bitstring 1 * RESERVED FOR IBM USE 013A 314 Signed 2 XSTBUFH4 Table entry index size 013C 316 Address 4 XSTBUFHI End of the BAT buffer 0140 320 Address 4 XSTBUFIX Next entry to take in BAT buffer 0144 324 Address 4 XSTBUFLO Addr of start of buffer 0148 328 Signed 4 XSTBUFER (500) The BAT buffer 00000918 XSTBUFND * Addr of last entry in the BAT buffer
XSTMG Storage Layout
*** XSTMG - Expanded storage management data
*
* +------+------+-------------+---------------------------+
* 0 |:STAFG|:FUTCT| XSTAVGAG | XSTSTATL |
* +------+------+-------------+---------------------------+
* 8 | XSTCTXTS | XSTCTXER |
* +---------------------------+---------------------------+
* 10 | XSTOTALB | XSTGUEST |
* +---------------------------+---------------------------+
* 18 | XSTINCRB | XSTCPINC |
* +---------------------------+---------------------------+
* 20 | XSTCPSTR | XSTPEDRT |
* +---------------------------+---------------------------+
* 28 | XSTMSKIP | XSTALLMB |
* +------+------+-------------+---------------------------+
* 30 |:MIGLK|:MIFLG| XSTBMULT | XSTCYCLE |
* +------+------+-------------+---------------------------+
* 38 | XSTFRMAQ | XSTNUMAQ |
* +-------------+-------------+-------------+-------------+
* 40 | XSTTGTEP | XSTTARGT | XSTEPOCH | XSTSTIME |
* +-------------+-------------+-------------+-------------+
* 48 | XSTADJTG | XSTMAXCT |
* +------+------+-------------+---------------------------+
* 50 |:MIFRM|:MIFL2| XSTMINAG | XSTITIME |
* +------+------+-------------+---------------------------+
* 58 | XSTSUMAG |
* +---------------------------+---------------------------+
* 60 | XSTUSRDM | XSTUSRCY |
* +---------------------------+---------------------------+
* 68 | XSTUSRSH | XSTCTGAL |
* +---------------------------+---------------------------+
* 70 | XSTBLKDM | XSTBLKCY |
* +---------------------------+---------------------------+
* 78 | XSTBLKSH | XSTBLKSY |
* +---------------------------+---------------------------+
* 80 | XSTQUEND | XSTMISAQ |
* +---------------------------+---------------------------+
* 88 | XSTMIFRS | XSTMIGS |
* +---------------------------+---------------------------+
* 90 | XSTCTPGM | XSTFROUT |
* +---------------------------+---------------------------+
* 98 | XSTLOTHR | XSTHITHR |
* +---------------------------+---------------------------+
* A0 | XSTRSTLO | XSTRLOCT |
* +---------------------------+---------------------------+
* A8 | XSTRSTHI | XSTRHICT |
* +---------------------------+---------------------------+
* B0 | XSTHICNT | XSTLOH2O |
* +---------------------------+---------------------------+
* B8 | XSTSKIPA | XSTCURAS |
* +---------------------------+---------------------------+
* C0 | XSTCURVM | XSTSEGCT |
* +---------------------------+---------------------------+
* C8 | XSTDDSAV | XSTMDCSA |
* +---------------------------+---------------------------+
* D0 | XSTCURSG | XSTLSTSG |
* +---------------------------+---------------------------+
* D8 | XSTDFRAS |///////////////////////////|
* +---------------------------+---------------------------+
* E0 | XSTNOIO | XSTCYCLS |
* +---------------------------+---------------------------+
* E8 | XSTFLCYC | XSTMRABI |
* +---------------------------+---------------------------+
* F0 | XSTSRABI | XSTSRGCT |
* +---------------------------+---------------------------+
* F8 | XSTSRSCT | XSTBPRCT |
* +---------------------------+---------------------------+
* 100 | XSTATVMD | XSTATLOW |
* +---------------------------+---------------------------+
* 108 | XSTATHI | XSTATSIZ |
* +---------------------------+---------------------------+
* 110 | XSTXBZIP | XSTXBGET |
* +---------------------------+---------------------------+
* 118 | XSTXBREL | XSTMAXK |
* +---------------------------+---------------------------+
* 120 | XSTINCRM |///////////////////////////|
* +---------------------------+---------------------------+
* 128 | XSTCPPAR | XSTCTXAV |
* +---------------------------+---------------------------+
* 130 | XSTDIRAN | XSTALCR |
* +------+------+-------------+---------------------------+
* 138 |:BUFLK|//////| XSTBUFH4 | XSTBUFHI |
* +------+------+-------------+---------------------------+
* 140 | XSTBUFIX | XSTBUFLO |
* +---------------------------+---------------------------+
* 148 | |
* = XSTBUFER =
* | |
* +-------------------------------------------------------+
* 918
*
*** XSTMG - Expanded storage management data
XSTMG Cross Reference
Symbol Dspl Value -------------- ---- ----- XSTADJTG 0048 XSTALCR 0134 XSTALLMB 002C XSTATHI 0108 XSTATLOW 0104 XSTATSIZ 010C XSTATVMD 0100 XSTAVGAG 0002 XSTBLKCY 0074 XSTBLKDM 0070 XSTBLKSH 0078 XSTBLKSY 007C XSTBMULT 0032 XSTBPRCT 00FC XSTBUFER 0148 XSTBUFHI 013C XSTBUFH4 013A XSTBUFIX 0140 XSTBUFLK 0138 XSTBUFLO 0144 XSTBUFND 0148 00000918 XSTCKGAL 0051 20 XSTCPINC 001C XSTCPPAR 0128 XSTCPSTR 0020 XSTCTGAL 006C XSTCTPGM 0090 XSTCTXAV 012C XSTCTXER 000C XSTCTXTS 0008 XSTCURAS 00BC XSTCURSG 00D0 XSTCURVM 00C0 XSTCYCLE 0034 XSTCYCLS 00E4 XSTCYEND 0051 40 XSTDCSS 0031 08 XSTDDSAV 00C8 XSTDFRAS 00D8 XSTDIRAN 0130 XSTEPOCH 0044 XSTEXTMP 0000 10 XSTFLAGS 0000 XSTFLCYC 00E8 XSTFLUSH 0031 20 XSTFNDDS 0051 10 XSTFRMAQ 0038 XSTFROUT 0094 XSTFUTCT 0001 XSTGUEST 0014 XSTHICNT 00B0 XSTHITHR 009C XSTINCRB 0018 XSTINCRM 0120 XSTITIME 0054 XSTLOH2O 00B4 XSTLOTHR 0098 XSTLSTSG 00D4 XSTMAXCT 004C XSTMAXK 011C XSTMDALL 0000 08 XSTMDCSA 00CC XSTMGMSZ 012C 00000130 XSTMGSTR 0000 XSTMIBLF 003C 10 XSTMIFLG 0031 XSTMIFL2 0051 XSTMIFRM 0050 XSTMIFRS 0088 XSTMIGLK 0030 XSTMIGS 008C XSTMINAG 0052 XSTMINTG 0051 80 XSTMISAQ 0084 XSTMISLP 0031 80 XSTMMAX 0032 0000000F XSTMMIN 0032 00000005 XSTMPDSB 0000 02 XSTMRABI 00EC XSTMSKIP 0028 XSTNAVAL 0000 04 XSTNCONF 0000 01 XSTNDONE 0051 04 XSTNOCYC 0031 0D XSTNOIO 00E0 XSTNORML 0031 40 XSTNSS 0031 04 XSTNUMAQ 003C XSTOFFLN 0000 01 XSTOTALB 0010 XSTPEDRT 0024 XSTPTIL 0031 10 XSTQUEND 0080 XSTRESUM 0031 02 XSTRHICT 00AC XSTRLOCT 00A4 XSTRREQD 0000 40 XSTRSTHI 00A8 XSTRSTLO 00A0 XSTSEGCT 00C4 XSTSHARE 0031 0C XSTSHAS 0031 01 XSTSKIPA 00B8 XSTSRABI 00F0 XSTSRGCT 00F4 XSTSRSCT 00F8 XSTSTAFG 0000 XSTSTATL 0004 XSTSTIME 0046 XSTSUMAG 0058 XSTTARGT 0042 XSTTGTEP 0040 XSTUSE8K 0051 08 XSTUSRCY 0064 XSTUSRDM 0060 XSTUSRSH 0068 XSTXBGET 0114 XSTXBREL 0118 XSTXBZIP 0110
Last updated on 5 Jun 2001 at 17:21:37 EDT.
Copyright IBM Corporation, 1990, 2001