DSP and SDSP trace records

A DSP record represents dispatching of a task. An SDSP record represents re-dispatching of a task after an SVC interruption. 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 is 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.

Minimal Trace Record Formats

DSP   ASCB.... hhhhhhhh CPU..... hhhh     PSW..... hhhhhhhh hhhhhhhh
                        PSW..... hhhhhhhh hhhhhhhh hhhhhhhh hhhhhhhh
                        TCB..... hhhhhhhh R15..... hhhhhhhh R0...... hhhhhhhh
                        R1...... hhhhhhhh

SDSP  ASCB.... hhhhhhhh CPU..... hhhh     PSW..... hhhhhhhh hhhhhhhh
                        PSW..... hhhhhhhh hhhhhhhh hhhhhhhh hhhhhhhh
                        TCB..... hhhhhhhh R15..... hhhhhhhh R0...... hhhhhhhh
                        R1...... hhhhhhhh

Comprehensive Trace Record Formats

 DSP          ASCB.... hhhhhhhh CPU..... hhhh     JOBN.... cccccccc    
              DSP-PSW. hhhhhhhh hhhhhhhh hhhhhhhh hhhhhhhh             
              TCB..... hhhhhhhh MODN.... yyyyyyyy R15..... hhhhhhhh    
              R0...... hhhhhhhh R1...... hhhhhhhh

 SDSP         ASCB.... hhhhhhhh CPU..... hhhh     JOBN.... cccccccc
              DSP-PSW. hhhhhhhh hhhhhhhh hhhhhhhh hhhhhhhh          
              TCB..... hhhhhhhh MODN.... yyyyyyyy R15..... hhhhhhhh 
              R0...... hhhhhhhh R1...... hhhhhhhh

ASCB hhhhhhhh

Address of address space control block.

CPU hhhh

Address of processor on which the task is dispatched.

PSW hhhhhhhh hhhhhhhh hhhhhhhh hhhhhhhh

DSP-PSW hhhhhhhh hhhhhhhh hhhhhhhh hhhhhhhh

Program status word under which the task is dispatched.

JOBN cccccccc

One of the following:

cccccccc: Name of the job associated with the task being dispatched
N/A: The record is for a system or started task
PPPPPPPP: A page fault occurred
********: An internal error occurred

TCB hhhhhhhh

Address of the task control block.

R15 hhhhhhhh

R0 hhhhhhhh

R1 hhhhhhhh

Data that will appear in general registers 15, 0, and 1 when the task is dispatched.

MODN cccccccc

cccccccc is one of the following:

mod_name: The name of a module that will receive control when the task is dispatched.
WAITTCB: Indicates that the system wait task is about to be dispatched.
SVC–T2: Indicates that a type 2 SVC routine that resides in the nucleus is about to be dispatched.
SVC–RES: Indicates that a type 3 SVC routine or the first load module of a type 4 SVC routine is about to be dispatched. The routine is located in the pageable link pack area (PLPA).
SVC–cccc: Indicates that the second or subsequent load module of a type 4 SVC routine is about to be dispatched. The module is located in the fixed or pageable link pack area (LPA). The last four characters of the module name are cccc.
**IRB***: Indicates that an asynchronous routine with an associated interruption request block (IRB) is about to be dispatched. No module name is available.
*ccccccc: Indicates that error fetch is in the process of loading an error recovery module. The last seven characters of the module name are ccccccc.
PPPPPPPP: A page fault occurred
********: An internal error occurred