address of the start of the trace table, TRACSTRT, is at location X'OC'. The
address of the byte following the end of the trace table, TRACEND, is at location X'10'. And the address of the next available trace table entry, TRACCURR, is at
location X'14'. Subtract 16 bytes (X'10') from the address stored at X'14'
(TRACCURR) to obtain the trace table entry for the last event completed.
The CP internal trace table is initialized during IPL. If you do not wish to record
events in the trace table, issue the MONITOR STOP command to suppress record­
ing. iref refid=debugm. The pages allocated to the trace table are not released
and recording can be restarted at any time by issuing the MONITOR START
command. If the VM/SP system should abnormally terminate and automatically
restart, the tracing of events on the real machine will be active. After a VM/SP IPL (manual or automatic), CP internal tracing is always active.
Introduction to Debugging 503 .

Type of Event External Interrupt SVC Interrupt Program Interrupt Machine Check Interrupt I/O Interrupt Free Storage
(FREE)
Return Storage
(FRET)
Enter Scheduler Queue Drop
Run User Start I/O Unstack I/O Interrupt Virtual CSW store
Test I/O Halt Device Module DMKPSA DMKSVC DMKPRG DMKMCH DMKIOS DMKFRE
DMKFRE DMKSCH DMKSCH DMKDSP DMKCNS DMKIOS DMKCPI DMKDSP DMKVSI DMKCPI DMKIOS DMKCNS DMKIOS DMKVSI DMKCPI Identification Code (hexadecimal) (See Note 1)
01
02
03
04
05
06
07 OS 09
OA
OB OC 00 OE
OF X'OOOOOOOOOO' GR140rGR15 (See Note 2)
First 3 Bytes of VMPSW Address of VMBLOK Address of VMBLOK Address of VMBLOK Address of VMBLOK Address of VMBLOK X'OOOOOO' Format of Trace Table Entry
First 4 bytes of S-byte Interrupt Code I/O Old PSW + 4
GR 0 at entry
GR 0 at entry Value of VMRSTAT, VMDSTAT, VMOSTAT, and VMQSTAT RUN USER Value from PSA Address of 10BLOK Address of VMBLOK Address of VMBLOK Address of 10BLOK Address of 10BLOK External Old PSW SVC Old PSW Program Old PSW Machine Check Old PSW CSW GR 1 at exit
GR 1 at entry
ser. Queue Recent History U I Dispatching Priority Priority User CPU Utilization
9 VMUPRIOR 10 VMQPRIOR 12 VMUHS RUNPSW Value from PSA CAW Virtual CSW Virtual CSW CAW
CAW
For CC = 1, CSW + 4
otherwise this field is
12 not used
For CC = 1, CSW + 4
otherwise this field is
12 not used
For CC = 1, CSW + 4
otherwise this field is
12 not used
Notes: 1. If the installation is running in attached processor mode, the identification code will be OR'd with an X'40' if the activity occurred on the attached processor. If the installation is running ECPS, the identification code is OR'd with an X'SO' if the activity occurred in microcode.
2. If the interrupt code (bytes 6 and 7) is OC, the contents of GR 14 are displayed. For all other interrupt codes, the contents of GR 15 are displayed.
3. Bytes 2 through 15 of a code 11 trace record represent a Basic Transmission Unit, sent or received by a 3704/3705. If CONSYSR/CONEXTR are zero, the
BTU was transmitted to the 3704/3705. If they are non-zero, the BTU was received. If CONTCMD equals X'7700', this is an unsolicited BTU response.
Figure 67 (Part 1 of 2). CP Trace Table Entries
504 VM/SP System Programmer's Guide