RCE and RLE allocation

Products

• IDMS
• IDMS - Database
• IDMS - ADS

Issue/Introduction

RCEs and RLEs are small control blocks which IDMS uses to control resources (RCEs) and keeps track of how those resources are linked to entities in the system which use them (RLEs).
 

Environment

CA-IDMS all supported releases.

Resolution

RCEs and RLEs are stored in the "second" pool 255 which mostly holds the runtime DMCL.
If you issue the command DCMT D ALL STO PO, you will see two pools with the number 255.
The first one is the "true" pool 255 - the one defined by the XA STORAGE POOL clause of the sysgen SYSTEM statement.
The second one is a piece of GETMAINed 31-bit z/OS storage which IDMS allocates at startup to hold the runtime DMCL and other static 31-bit control block areas.
This second pool 255 is allocated by IDMS as needed and not something that the user can define in sysgen.

D ALL STO PO                                                            
POOL   ADDRESS   SIZE CUSHION  INUSE    HWM       TIMES SOS  PFIX  CONTAINS   
                                                                    TYPES     
   0  0005F000   512K    100K    80K    80K               0   NO   SY,TR,DB   
   1  000DF000   512K    128K    96K   144K               0   NO   SH,SK,US,UK
 128  3B5A7000  4000K   3000K   716K   736K               0   NO   SH,SK,US,UK
 130  3B98F000  1000K    100K   148K   176K               0   NO   TR,DB      
 255  3BA89000  5000K      0K  2272K  2296K               0   NO   SY         
 255  3AF0C000  1944K      0K  1944K  1944K               0   NO   SY

If you issue the command DCMT D MEM MAP, you can see that the address locations of the areas from the DMCL to the ILEAREA coincide with the addresses of the second pool 255 above (3AF0C000 + 1944K = 3B0F2000).

D MEM MAP                                                               
RHDCOS00      7000  OPT          297D0  NLT          2AC20  CSA          2CDB0
LKM          340E0  SCAAREA      34B80  CCE          35520  STGPOOL      5F000
PTT          60208  ECBLIST     15F4A0  CSVCAREA    160D20  TCA         163E80
DCEAREA     163F40  TCEAREA     165040  PGMPOOL     18C000  RENTPOOL    286000
RHDCD05V    2B2400  RHDCD0EV    2B7400  RHDCD07Q    2C5C00  RHDCD00B    2C7800
RHDCD0LX    2C9790  RHDCD03Q    2D0A00  HIADDR      4D8044  SVC172      B503C8
EREAREA   2679E578  ESE       39BE09E0  CV65DMCL  3AF0C490  RUA       3AF32990
DDT       3AF34108  LTT       3AF34288  TCESTACK  3AF4AE08  ABENDSTG  3B013288
QDT       3B016588  TDT       3B018108  PDT       3B02A608  SCT       3B0D4308
MPMODTBL  3B0D5A88  RCA       3B0D6308  RLEAREA   3B0D63C8  RCEAREA   3B0DAB20
DPEAREA   3B0E6920  ILEAREA   3B0EB660  XASTGPL   3B5A7000  XAPGMPL   3BF6B000
XARENTPL  3BFE8000  IDMSDBIO  3BFE80B8  IDMSDBMS  3C00B0B8  RHDCD04W  3C2B9A00
RHDCD0LV  3C2BE838  RHDCD0ZU  3C2C1000  RHDCD0IP  3C2C4800  RHDCRUSD  3CAEB600
RHDCLGSD  3CAEC000  RHDCTRSD  3CAECC00  PMONCIOD  3CAF2260  PMONCROL  3CAF5800
RHDCDEAD  3CAF7200  TRCEBUFS  3DAA6000

Additional Information

Task Resource Usage
SYSTEM Statement
DCMT DISPLAY ALL STORAGE POOLS Command
DCMT DISPLAY MEMORY Command