SRXBK Back to Index page
 
Prolog 
Control Block Contents 
   SRXBK DSECT
Storage Layout 
Cross Reference (Contains links to field and bit definitions)
Programming Interface Information:
This information is NOT intended to be
used as Programming Interfaces of z/VM.


  SRXBK Prolog Top of page
 
 NAME       : HCPSRXBK
 DESCRIPTION: System Resource Management block extensions
 DSECT      : SRXBK
 FUNCTION   : HCPSRXBK contains original SRMBK fields which are
              duplicated for Mixed-Engine partitions.  These
              fields are used by the System Resource Manager
              (Scheduler) in the maintainance of user lists and
              calculation of various scheduling parameters.
 LOCATED BY : SRMXTBL table of SRXBK pointers by processor
              type
 CREATED BY : HCPIST during system initialization
 DELETED BY : Never deleted
 REFERENCES : None
 SERIALIZED : Scheduler lock (SRMSLOCK)
 RELOCATION CONSIDERATIONS : None
 COMPATIBILITY AND MIGRATION CONCERNS : An SRXBK exists for
              each processor type that is valid in a Mixed-Engines
              configuration.  Prior to Mixed-Engines support, these
              fields were global scheduler fields.  Now they must
              be viewed as valid for a particular processor type
              only.  For example, when processing the SRXBK for
              type zAAP, SRXMXSHR is the largest SHARE of system
              that can be delivered to a single VMDBK of type
              zAAP.
 
 
  SRXBK Control Block Content Top of page
 

 SRXBK DSECT Top of page
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure SRXBK System Resource Management block extensions 0000 0 Signed 4 SRXDLSCN Dispatch list scan header. This is the point at which HCPSTK's LINKDS subroutine is to begin scanning the dispatch list for an insertion point whenever adding a user 0004 4 Address 4 SRXDLADD Pointer to the last VMDBK added to the D-list ahead of ATOD. Used to reduce scans in the list. Timing Parameters NOTES : The assembler construct 'FL8S12' is used to generate a fixed-point number which represents a time value (in microseconds) in TOD clock format or CPU timer format. 'FL8S12E6' is used when specifying a time value in seconds (rather than microseconds). 0008 8 Signed 8 SRXHIDSP Dispatching priority of the highest priority user on the dispatch list at the time of the last major reshuffle (HCPDSBRV) less an adjustment interval to allow for continuing transactions returning to the dispatch list. The highest priority user has the lowest value of VMDDPRTY. This field is the basis for computing field DSVPRIOR in the PLDV. DSVPRIOR = VMDDPRTY - SRXHIDSP. (at least 32 bits of the result). 0010 16 Signed 8 SRXATOD Artificial TOD. This TOD only advances at the rate the system is running user work. 0018 24 Signed 4 SRXTOTLS (0) An equate used as an index base to reference one of the next two fields, srmreldl and srmabsdl. Code depends on these two fields being fullwords and following IN THE GIVEN ORDER. 0018 24 Signed 4 SRXRELDL The sum of the relative shares of all RELATIVE share holders (excluding dedicated VMDBKs) currently in the dispatch list. This field is protected by the scheduler lock. 001C 28 Signed 4 SRXABSDL The sum of the absolute shares of all VMDBKs (excluding dedicated VMDBKs) currently in the dispatch list. This field is protected by the scheduler lock. 0020 32 Signed 4 SRXTOTDE (0) An equate used as an index base to reference one of the next two fields, srmrelde and srmabsde. Code depends on these two fields being fullwords and following in the given order. 0020 32 Signed 4 SRXRELDE The sum of the relative shares of all relative share holders currently in the eligible and dispatch list. This field is protected by the scheduler lock. 0024 36 Signed 4 SRXABSDE The sum of the absolute shares of all VMDBKs currently in the eligible and dispatch list. This field is protected by the scheduler lock. 0028 40 Signed 2 SRXNCPUA The number of CPUs available to schedule time on for non-dedicated users. This field is protected by the scheduler lock. 002A 42 Signed 2 SRXPKCNT The number of parked CPUs. 002C 44 Address 4 SRXLLIST Anchor for the limit-list. Contains address of 1st VMDBK in list, or zero if list is empty. VMDBKs are forward and backward chained via VMDLFPNT & VMDLBPNT. 0030 48 Dbl-Word 8 SRXATODD A timestamp (TOD). The deadline for current ATOD-interval to end. Each CPU will copy this into its PFXATODD. But PFXATODD will often be an iteration behind SRXATODD. 0038 56 Dbl-Word 8 SRXCHKIN A timestamp (TOD). Time when the first-checker CPU last checked in (to start current ATOD-interval). Equals PFXCHKIN of first-checker. 0040 64 Dbl-Word 8 SRXCHKTW A timestamp (TOD). Time when the tracked-wait masks (SRXASKT1 and SRXASKT2) should next be checked. (Set to something like TOD+10ms.) 0048 72 Signed 8 SRXATOD2 Artificial TOD2. This TOD advances at the same rate as the TOD clock. It is updated each time SRXATOD is adjusted. This field is used to determine when a VMDBK should be dropped from the limit list. 0050 80 Dbl-Word 8 SRXASKTW Mask has a bit for each logical CPU. Bit is on if the CPU is currently in "tracked-wait" mode. 0058 88 Dbl-Word 8 SRXASKT1 Mask has a bit for each logical CPU. Bit is on if CPU performed an ATOD-check-in since mask was last reset (as timed by SRMASKTM). 0060 96 Dbl-Word 8 SRXASKT2 Mask has a bit for each logical CPU. Bit is on if CPU performed an ATOD-check-in during previous interval (as timed by SRMASKTM). 0068 104 Signed 4 SRXTRKCT Count of tracked-wait-mode CPUs. 006C 108 Address 4 SRXLODSP Pointer to the VMDBK just above ATOD in the dispatch list. It is advanced only when ATOD is up- dated, and so may not always point to quite the last VMDBK. PURPOSE: Save scanning overhead when locating VMDBKs which have aged out of the SRXCTHRU bunch. SRXRTHRU and SRXCTHRU are two tables, used in normalizing users' VMDRTHRUs. (VMDRTHRU is the user's "required throughput" i.e., his SHARE after it has been adjusted to compensate him for any delay in the eligible list.) 0070 112 Signed 4 SRXRTHRU (0) Start of array (table) of sums of VMDRTHRU values for all VMDBKs in the dispatch list. 0070 112 Signed 4 SRXRTHRN Total VMDRTHRU of VMDBKs in the dispatch list which are not cur- rently hitting their max-SHAREs. 0074 116 Signed 4 SRXRTHRL Total VMDRTHRU of VMDBKs in the dispatch list which are current- ly hitting their max-SHAREs. (LIMITed and hitting the limit.) 0078 120 Signed 4 SRXRTHRZ (0) End of array (table). Notes : SRXRTHRN and SRXRTHRL must have the same offsets within the SRXRTHRU array as SRXCTHRN and SRXCTHRL have in the SRXCTHRU array. 0078 120 Signed 4 SRXCTHRU (0) Start of array (table) of sums of VMDRTHRU values of compute- bound VMDBKs (literally, VMDBKs below ATOD) in the dispatch list. 0078 120 Signed 4 SRXCTHRN Total VMDRTHRU of compute-bound VMDBKs not hitting max-SHARE. 007C 124 Signed 4 SRXCTHRL Total VMDRTHRU of compute-bound VMDBKs hitting max-SHARE. 0080 128 Signed 4 SRXCTHRZ (0) End of array (table). General Data Fields 0080 128 Signed 4 SRXMXSHR Largest SHARE of system that can be delivered to a single VMDBK. It is the reciprocal of SRXNCPUA. (E.g., 0.25 on a 4-way system.) 0084 132 Signed 4 SRXLLCNT Count of adds to the limit-list. This count is only approximate, it does not include adds result- from virtual-MP priority drop. 0088 136 Signed 4 SRXCONLL Count of users actually ON the Limit List. This count is serialized by the scheduler lock. 008C 140 Address 4 SRXDVLST Anchor into the linked list of PLDV's linked by DSVNXTDV. The following fields are bit masks for which each real processor has a corresponding unique bit. 0090 144 Dbl-Word 8 SRXLCPUA Mask containing the logical CPU ids (PFXLCPUA) of CPUs which are online, non-dedicated, and unparked. (The difference of SRXNCPUA and SRXPKCNT should tell how many bits are on in SRXLCPUA.) See also SYSLCPUA, which is similar, but shows dedicated, parked, and also offline CPUs whose prefix pages have not been freed. 0098 152 Dbl-Word 8 SRXPKMSK Mask containing the logical CPU ids (PFXLCPUA) of CPUs which are parked. (The counter SRXPKCNT indicates how many bits are on in SRXPKMSK.) See also SRMPKMSK, which is a mask for parked CPUs of all types. 00A0 160 Address 4 SRXTRQWT Points to TRQBK used to bring us out of wait state when it is time to dequeue VMDBKs from limit-list. 00A4 164 Bitstring 1 SRXFLAGS General flags 1... .... SRXSYSMP X'80' SRXSYSMP This CPU type can dispatch SYSTEMMP work (CP + IFL) 00A5 165 Bitstring 1 SRXEXUSE SRM EXCESSUSE field 00000010 SRXEXHGH 16 SRXEXHGH -Indicates the system should be aggressive in using unentitled CPU capacity. 00000008 SRXEXMED 8 SRXEXMED -Indicates the system should be moderately aggressive in using unentitled CPU capacity. 00000001 SRXEXLOW 1 SRXEXLOW -Indicates the system should not be aggressive in using unentitled CPU capacity. 00A6 166 Bitstring 1 SRXWRKCI Workload confidence interval - integer between 50 and 99, specifying the percentage confidence level 00A7 167 Bitstring 1 SRXTVCNF T/V ratio confidence percentage - integer between 50 and 99, specifying the confidence level of the T/V ratio ceiling projection. 00A8 168 Signed 4 SRXCPPAD SRM CPUPAD value, a scaled number where X'00010000' represents one CPU 00AC 172 Signed 2 SRXPMAX Maximum number of CPUS that can be parked in an interval 00AE 174 Bitstring 2 * Reserved for IBM use 00B0 176 Address 4 SRXLASDV HL address of the last DSVBK to which a VMDBK was assigned during the round-robin phase of rebalance which is used when all capacity of a given type is depleted. Reset at the start of each rebalance 00B4 180 Signed 4 SRXENTVM This is a scaled number between X'00000001' and X'00010000' representing the portion of a real CPU to which vertical medium CPUs are entitled. Serialized by Vary Proc lock. 00B8 184 Signed 4 SRXNOTVH Capacity assigned to all CPUs other than vertical high CPUs. 00BC 188 Bitstring 4 * Reserved for IBM use. 00C0 192 Dbl-Word 8 SRXNICPF (10) Circular array of Next Interval Capacity Factors. RCCTOPDX is to be used as an index to find the most recent element. Each element is a factor to be used to adjust the remaining capacity during the next interval. This value is stored in floating point format. 0110 272 Dbl-Word 8 SRXNIPAD (10) Circular array of Next Interval Tolerance Padding values. RCCTOPDX is to be used as an index to find the most recent element. Stored in floating point format. 0160 352 Signed 4 SRXLIUSG (10) Circular array of Total CPU usage of this type during the last interval. RCCTOPDX is to be used as an index to find the most recent element. This value is scaled such that x'10000' equals one full CPU. 0188 392 Signed 4 SRXVMDCT (10) Circular array of counts of the number of VMDBKs on the global cyclic list with this dispatch CPU type when gathering informa- tion to be used for dispatch vector rebalance. RCCTOPDX is to be used as an index to find the most recent element. 01B0 432 Signed 4 SRXACGUS (10) Circular array of the average CPU usage of the VMDBKs of this type in the last interval. RCCTOPDX is to be used as an index to find the most recent element. This value is scaled such that x'10000' equals one full CPU. 0000003B SRXSIZE (*-SRXBK+7)/8 size in double words 000001D8 SRXBSIZE SRXSIZE*8 size in bytes
 
 
  SRXBK Storage Layout Top of page
 
          
*** SRXBK - System Resource Management block extensions
*
*     +---------------------------+---------------------------+
*   0 |         SRXDLSCN          |         SRXDLADD          |
*     +---------------------------+---------------------------+
*   8 |                       SRXHIDSP                        |
*     +-------------------------------------------------------+
*  10 |                       SRXATOD                         |
*     +---------------------------+---------------------------+
*  18 |         SRXRELDL          |         SRXABSDL          |
*     +---------------------------+---------------------------+
*  20 |         SRXRELDE          |         SRXABSDE          |
*     +-------------+-------------+---------------------------+
*  28 |  SRXNCPUA   |  SRXPKCNT   |         SRXLLIST          |
*     +-------------+-------------+---------------------------+
*  30 |                       SRXATODD                        |
*     +-------------------------------------------------------+
*  38 |                       SRXCHKIN                        |
*     +-------------------------------------------------------+
*  40 |                       SRXCHKTW                        |
*     +-------------------------------------------------------+
*  48 |                       SRXATOD2                        |
*     +-------------------------------------------------------+
*  50 |                       SRXASKTW                        |
*     +-------------------------------------------------------+
*  58 |                       SRXASKT1                        |
*     +-------------------------------------------------------+
*  60 |                       SRXASKT2                        |
*     +---------------------------+---------------------------+
*  68 |         SRXTRKCT          |         SRXLODSP          |
*     +---------------------------+---------------------------+
*  70 |         SRXRTHRN          |         SRXRTHRL          |
*     +---------------------------+---------------------------+
*  78 |         SRXCTHRN          |         SRXCTHRL          |
*     +---------------------------+---------------------------+
*  80 |         SRXMXSHR          |         SRXLLCNT          |
*     +---------------------------+---------------------------+
*  88 |         SRXCONLL          |         SRXDVLST          |
*     +---------------------------+---------------------------+
*  90 |                       SRXLCPUA                        |
*     +-------------------------------------------------------+
*  98 |                       SRXPKMSK                        |
*     +---------------------------+------+------+------+------+
*  A0 |         SRXTRQWT          |:FLAGS|:EXUSE|:WRKCI|:TVCNF|
*     +---------------------------+------+------+------+------+
*  A8 |         SRXCPPAD          |  SRXPMAX    |/////////////|
*     +---------------------------+-------------+-------------+
*  B0 |         SRXLASDV          |         SRXENTVM          |
*     +---------------------------+---------------------------+
*  B8 |         SRXNOTVH          |///////////////////////////|
*     +---------------------------+---------------------------+
*  C0 |                                                       |
*     =                       SRXNICPF                        =
*     |                                                       |
*     +-------------------------------------------------------+
* 110 |                                                       |
*     =                       SRXNIPAD                        =
*     |                                                       |
*     +-------------------------------------------------------+
* 160 |                                                       |
*     =                       SRXLIUSG                        =
*     |                                                       |
*     +-------------------------------------------------------+
* 188 |                                                       |
*     =                       SRXVMDCT                        =
*     |                                                       |
*     +-------------------------------------------------------+
* 1B0 |                                                       |
*     =                       SRXACGUS                        =
*     |                                                       |
*     +-------------------------------------------------------+
* 1D8
*
*** SRXBK - System Resource Management block extensions
 
 
  SRXBK Cross Reference Top of page
 
 
Symbol         Dspl Value
-------------- ---- -----
SRXABSDE       0024
SRXABSDL       001C
SRXACGUS       01B0
SRXASKTW       0050
SRXASKT1       0058
SRXASKT2       0060
SRXATOD        0010
SRXATODD       0030
SRXATOD2       0048
SRXBSIZE       01B0 000001D8
SRXCHKIN       0038
SRXCHKTW       0040
SRXCONLL       0088
SRXCPPAD       00A8
SRXCTHRL       007C
SRXCTHRN       0078
SRXCTHRU       0078
SRXCTHRZ       0080
SRXDLADD       0004
SRXDLSCN       0000
SRXDVLST       008C
SRXENTVM       00B4
SRXEXHGH       00A5 00000010
SRXEXLOW       00A5 00000001
SRXEXMED       00A5 00000008
SRXEXUSE       00A5
SRXFLAGS       00A4
SRXHIDSP       0008
SRXLASDV       00B0
SRXLCPUA       0090
SRXLIUSG       0160
SRXLLCNT       0084
SRXLLIST       002C
SRXLODSP       006C
SRXMXSHR       0080
SRXNCPUA       0028
SRXNICPF       00C0
SRXNIPAD       0110
SRXNOTVH       00B8
SRXPKCNT       002A
SRXPKMSK       0098
SRXPMAX        00AC
SRXRELDE       0020
SRXRELDL       0018
SRXRTHRL       0074
SRXRTHRN       0070
SRXRTHRU       0070
SRXRTHRZ       0078
SRXSIZE        01B0 0000003B
SRXSYSMP       00A4 80
SRXTOTDE       0020
SRXTOTLS       0018
SRXTRKCT       0068
SRXTRQWT       00A0
SRXTVCNF       00A7
SRXVMDCT       0188
SRXWRKCI       00A6
 
This information is based on z/VM 6.3.0 Last updated on 22 May 2013 at 13:55:49 EDT.
Copyright IBM Corporation, 1990, 2013