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IEFU85 — SMF Record Exit z/OS MVS Installation Exits SA23-1381-00 |
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Topics for This Exit Appear as Follows:
The SMF record exit IEFU85 is used for a caller who is running in cross memory mode. The exit routine receives control when the caller invokes the SMFEWTM macro, specifying BRANCH=YES and MODE=XMEM and when ASCB does not equal PSAAOLD (the home primary ASID). After exit routine processing, IEFU85 returns a code that specifies whether the SMF record should be written to the SMF data set. The SMFEWTM macro allows the issuer to branch directly to the SVC routine without issuing the SVC. IEFU85 does not receive control for records that are suppressed because of options selected at IPL time or via the SET SMF command. You can use IEFU85 to:
Defining the Exit in SMFPRMxxIn the SMF parmlib member (SMFPRMxx), specify IEFU85 on the EXITS option of either the SYS or SUBSYS parameters, depending on the scope of work (system-wide or subsystem-wide) the exit is to affect. If you use the SUBSYS option, the system invokes the IEFU85 routine only for work running under the subsystems you specify on SUBSYS. If you use the SYS option, the system invokes the IEFU85 routine for work running under any SMF-defined subsystem, such as JES2, JES3, STC, ASCH, OMVS, or TSO. For more information about coding the EXITS option, see the description of SMFPRMxx in z/OS MVS Initialization and Tuning Reference. Controlling the Exit Routine Through the Dynamic Exits FacilityIBM® has defined the IEFU85 installation exit to the dynamic exits facility. You can refer to the exit by the name SYS.IEFU85 or SYSyyy.IEFU85. See the description of the SMFPRMxx parmlib member in z/OS MVS Initialization and Tuning Reference for an explanation of the naming conventions for SMF exit routines. You can use the EXIT statement of the PROGxx parmlib member, the SETPROG EXIT operator command, or the CSVDYNEX macro to control this exit and its exit routines. To define IEFU85 to the dynamic exits facility, you must specify the exit in both PROGxx and SMFPRMxx. The system does not call the exit if it is defined in PROGxx only. If you do not plan to use the dynamic exits facility for this exit, you need only define IEFU85 in SMFPRMxx. If you do not associate any exit routines with exit IEFU85 in PROGxx, the system defaults to using the exit routine name that matches the exit name (IEFU85). If you associate exit routines with this exit in PROGxx, the system does not use the default exit routine. If you need the default exit routine, you should explicitly add it to PROGxx. You can use the ADDABENDNUM
and ABENDCONSEC parameters on the CSVDYNEX REQUEST=ADD macro or the
ABENDNUM parameter of the SETPROG EXIT operator command to limit the
number of times the exit routine abnormally ends before it becomes
inactive. An abend is counted when both of the following conditions
exist:
Exit Routine EnvironmentIEFU85
receives control in the following environment:
Exit RecoveryIf IEFU85 abnormally terminates, SMF, in most cases, does not terminate. SMF marks the exit as not valid and issues message IEE952I to the operator. If the exit performs a critical function, the operator can issue a SET SMF or SETSMF command to terminate recording. Otherwise, SMF recording continues but bypasses the installation exit routine. A functional recovery routine (FRR) is set up by IEEMB830 (the SVC 83 routine) because the caller is in cross memory mode. IBM strongly recommends that you set up an FRR recovery routine to handle errors that might occur during the execution of your exit routine. An FRR is set up by the module that calls IEFU85; the recovery routine, if it gets control, will prevent SMF from ending if the exit routine abnormally ends. If this recovery routine gets control on two consecutive invocations of the exit, SMF requests that the exit routine be marked inactive, preventing any further invocations of that exit routine. The system issues message CSV430I, naming the exit and the exit routine. If the exit performs a critical function, the operator can issue a SET PROG or SETPROG MODIFY command to change the status of the exit to active. This should be done only if you have corrected the program, or if you know the error conditions are transient. Whether or not the exit routine continues to be invoked depends on the abend processing of the dynamic exits facility. Exit Routine ProcessingEach SMF record is passed to an installation exit (either IEFU83, IEFU84, or IEFU85) before it is written to the SMF data set. If you use the SMFEWTM macro and specify BRANCH=YES MODE=XMEM, SMF invokes installation exit IEFU85. The SMFEWTM macro verifies that SMF recording is active and allows the issuer to branch directly to the SVC routine without issuing the SVC. BRANCH=YES causes the macro to generate a call to the subroutine that moves the data to the SMF buffer. IEFU85 places a return code in register 15 before returning control; the code indicates whether the record is to be written to the SMF data set. Programming ConsiderationsIEFU85 must be reenterable and refreshable, because PLPA pages are stolen. That is, PLPA pages can be paged in but not paged out, and subsequent page-ins overlay any code changes. IEFU85 cannot access installation-defined data sets. Because IEFU85 is running in cross-memory mode, the exit routine cannot issue any SVCs. The addresses of the user communication and user identification fields of the common exit parameter area (a copy of the first 36 bytes of the JMR) are not passed to the IEFU85 exit routine. To obtain these addresses, the exit routine can follow pointers from the PSA to the TCB to the JMR. In the PSA, the PSATOLD points to TCB. In the TCB, the TCBTCT field points to the TCT. In the TCT, the TCTJMR field points to the JMR. The JMR and the PSA are mapped by macros IEFJMR and IHAPSA, respectively. See z/OS MVS Data Areas in z/OS Internet Library at http://www.ibm.com/systems/z/os/zos/bkserv/ for the mapping of the JMR, and z/OS MVS Data Areas, Vol 5 (SSAG-XTLST) for the mappings of the TCB and the TCT. APPC/MVS Consideration: You might want your exit routine to perform specific processing for work initiated by the APPC/MVS transaction scheduler. To enable your exit routine to determine when it has been invoked during this type of processing, have the routine check the OUCBSUBN field in the OUCB control block. For APPC/MVS TPs, this field is set to 'ASCH' (EBCDIC). The exit routine can access OUCBSUBN by chaining through pointers from the PSA to the ASCB to the OUCB. In the PSA, the PSAAOLD points to the ASCB. In the ASCB, the ASCBOUCB field points to the OUCB. The ASCB, OUCB, and the PSA are mapped by macros IHAASCB, IRAOUCB, and IHAPSA, respectively. The mappings are described in z/OS MVS Data Areas in z/OS Internet Library at http://www.ibm.com/systems/z/os/zos/bkserv/. Macro Instructions and Restrictions: IEFU85 can issue only macros that can run in cross-memory mode. See the macro summary in z/OS MVS Programming: Assembler Services Reference ABE-HSP for information on macros that can run in cross-memory mode. IEFU85 cannot use the SMFWTM or SMFEWTM macro to write to the SMF data set. Entry SpecificationsSMF passes to IEFU85 the address of a fullword that points to the SMF record. Registers at Entry: The contents of the registers on entry to the exit are as follows.
Parameter Descriptions: Register 1 points
to the following address:
Figure 1. IEFU85 Input Parameter
Structure
Return SpecificationsA return code from IEFU85 indicates whether the current SMF record is to be suppressed. If you associate multiple exit routines with IEFU85, you can specify how the return information is to be handled using the ATTRIB KEEPRC function of the SETPROG EXIT command, the EXIT statement of PROGxx, or CSVDYNEX services. If multiple exit routines match the ATTRIB KEEPRC criteria, the system returns information from the exit routine that finished first. If you do not specify the ATTRIB KEEPRC function, the system returns the information from the exit routine whose return value was the greatest. If multiple exit routines return with the same highest value, the return information from the exit routine that finished first will be returned. If you associate multiple exit routines with exit IEFU85, and any of those exit routines return with a value of 4, the current SMF record is suppressed. Registers at Exit: Upon return from the exit processing, the register contents must be as follows.
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Copyright IBM Corporation 1990, 2014
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