SVC and SVCR trace records

An SVC record represents a supervisor call (SVC) interruption. An SVCR record represents an exit from a supervisor call. SDSP interruptions also build SVC exit records with label SDSP. When both DSP and SVC options are in effect, the SVCR format of trace record is produced by IPCS.

If the trace data contains an SVC exit record, the label that appears in the formatted output will depend on the options selected during IPCS.

If the SVC option is selected in the IPCS dialog, the SVC exit record and the SVC number will appear with the label SVCR.
If only the DSP option is chosen in the IPCS dialog, the formatted output record will remain unchanged; DSP and SDSP labels will appear in the formatted output and no SVC number will be present.
If both DSP and SVC options are active in IPCS, the SVCR along with SVC number will appear.

It can be concluded, if SVC is one of the options selected during IPCS formatting, all SVC exit records will appear with label SVCR along with SVC number.

The format of an SVC and SVCR trace record depends on the SVC interruption being traced. For a break down of the information that GTF collects for each SVC, see the SVC Summary chapter of z/OS MVS Diagnosis: Reference. The formats shown are typical.

Minimal Trace Record Format

SVC   CODE.... hhh  ASCB.... hhhhhhhh CPU..... hhhh     
                    PSW..... hhhhhhhh hhhhhhhh hhhhhhhh hhhhhhhh
                    TCB..... hhhhhhhh R15..... hhhhhhhh R0...... hhhhhhhh 
                    R1...... hhhhhhhh

SVCR  CODE.... hhh  ASCB.... hhhhhhhh CPU..... hhhh     
                    PSW..... hhhhhhhh hhhhhhhh hhhhhhhh hhhhhhhh
                    TCB..... hhhhhhhh R15..... hhhhhhhh R0...... hhhhhhhh 
                    R1...... hhhhhhhh

Comprehensive Trace Record Format

SVC..... hhh   ASCB.... hhhhhhhh CPU..... hhhh     JOBNAME. cccccccc 
               OLD-PSW. hhhhhhhh hhhhhhhh hhhhhhhh hhhhhhhh          
               TCB..... hhhhhhhh MODN.... yyyyyyyy R15..... hhhhhhhh 
               R0..... hhhhhhhh R1..... hhhhhhhh

SVCR..... hhh   ASCB.... hhhhhhhh CPU..... hhhh     JOBNAME. cccccccc
                OLD-PSW. hhhhhhhh hhhhhhhh hhhhhhhh hhhhhhhh         
                TCB..... hhhhhhhh MODN.... yyyyyyyy R15..... hhhhhhhh 
                R0..... hhhhhhhh R1..... hhhhhhhh

SVC CODE hhh

SVC hhh

For SVC, and for SVCR when not X'FFxx': SVC interruption code, which is also called the SVC number.
For SVCR when X'FF00': completion of the system-initiated processing involved with ATTACH, LINK, XCTL or SYNCH processing prior to the target routine getting control.
For SVCR when X'FF01': initial system-initiated processing involved with XCTL processing prior to the target routine getting control.

ASCB hhhhhhhh

Address of the ASCB for the address space in which the interruption occurred.

CPU hhhh

Address of the processor on which the interruption occurred.

JOBNAME cccccccc

One of the following:

cccccccc: Name of the job associated with SVC interruption
SSSSSSSS: Unavailable; GTF cannot provide data for the SVC due to security considerations.
********: An internal error occurred

PSW hhhhhhhh hhhhhhhh hhhhhhhh hhhhhhhh

OLD-PSW hhhhhhhh hhhhhhhh hhhhhhhh hhhhhhhh

DSP-PSW hhhhhhhh hhhhhhhh hhhhhhhh hhhhhhhh

Program status word stored when the interruption occurred.

For SVC, and for SVCR when SVC Code is not X'FFxx': Program status word stored when the interruption occurred.
For SVCR when SVC Code is X'FF00': PSW of the target routine that will get control as a result of ATTACH, LINK, XCTL or SYNCH processing.
For SVCR when SVC Code is X'FF01': PSW of a system routine that will get control as a result of initial processing involved with XCTL.

TCB hhhhhhhh

Address of the TCB for the interrupted task, that is, the task that issued the SVC instruction.

R15 hhhhhhhh

R0 hhhhhhhh

R1 hhhhhhhh

Data in general registers 15, 0, and 1 when the SVC instruction ran.

MODN cccccccc

cccccccc is one of the following:

mod_name: The name of a module that will receive control when the task is dispatched.
SVC–T2: Indicates a type 2 SVC routine resident in the nucleus.
SVC–RES: Indicates a type 3 SVC routine or the first load module of a type 4 SVC routine. The routine is located in the pageable link pack area (PLPA).
SVC cccc: Indicates the second or subsequent load module of a type 4 SVC routine. The routine is located in the fixed or pageable link pack area (LPA). The last four characters of the load module name are cccc.
**IRB****: Indicates an asynchronous routine with an associated interruption request block. No module name is available.
*cccccc: Indicates an error recovery module. The last seven characters of the load module name are cccccc.
PPPPPPPP: A page fault occurred
********: An internal error occurred
DDNAM cccccc: Name of the DD statement associated with the SVC, if applicable.
additional fields: Vary with the SVC number. These fields are described for the SVC in the z/OS MVS Diagnosis: Reference