Message
DMKMCH612W MACHINE CHECK; TIMING
FACILITIES DAMAGE; RUN SEREP DMKMCT620I MACHINE CHECK; ATTACHED PROCESSOR NOT BEING USED DMKMCH622W MACHINE CHECK; MULTIPLE CHANNEL ERRORS DMKACR622W MACHINE CHECK; MULTIPLE CHANNEL ERRORS DMKCCH603W CHANNEL ERROR, RUN SEREP, RESTART SYSTEM DMKACR603W CHANNEL ERROR, RUN SEREP, RESTART SYSTEM DMKCPI955W INSUFFICIENT STORAGE FOR VM/SP DMKMCH622W MACHINE CHECK; MULTIPLE CHANNEL ERRORS DMSABN148T SYSTEM ABEND xxx
CALLED FROM xxxxxx Others Refer to OS and DOS publications
for the abnormal termination messages.
Figure 60 (Part 3 of 3), Abend Messages
Type of Abend
An error has occurred in the timing facilities.
Probable hardware error.
A malfunction alert, clock error or instruction
processing error occurred on the attached
processor. The system continues to run in
uniprocessor mode.
CP termination without automatic restart. On a 303x processor, an error affecting one
or more channels in a channel group has
occurred. CP enters a disabled wait state
with code 001 in the PSW.
There was a channel check condition from
which the channel check handler could not
recover. CP enters the wait state with code 002 in the PSW.
The generated system requires more real
storage than is available. CP enters the disa­
bled wait state with code OOD in the PSW.
There was a group error machine check from
which the machine check handler could not
recover. CP enters a wait state with code 001 in the PSW.
CMS abend, system will accept commands
from the terminal. Enter the. DEBUG com­
mand and then the DUMP subcommand to
have CMS dump storage on the printer.
When OS or DOS abnormally terminates on a
virtual machine, the message issued and the
dumps taken are the same as they would be if OS or DOS abnormally terminated on a real
machine.
Another obvious indication of a problem is unexpected output. If your output
is missing, incorrect, or in a different format than expected, some problem
exists.
Identifying the Problem Unproductive processing time is another symptom of a problem. This problem
is not easily recognized, especially in a timesharing environment.
Two types of problems are easily identified: abnormal termination is indicated
by an error message, and unexpected results become apparent once the output
is examined. The looping and wait state conditions are not as easily identified.
Introduction to Debugging 469

Identifying the Problem
Analyzing the Problem 470 VM/SP System Programmer's Guide Unproductive processing time is another symptom of a problem. This problem
is not easily recognized, especially in a timesharing environment.
Two types of problems are easily identified: abnormal termination is indicated
by an error message, and unexpected results become apparent once the output
is examined. The looping and wait state conditions are not as easily identified.
When using VM/SP, you are normally sitting at a terminal You may have a
looping condition if your program takes longer to execute than you anticipated.
Also, check your output. If the number of output records or print lines is
greater than expected, the output may really be the same information repeated
many times. Repetitive output usually indicates a program loop.
Another way to identify a loop is to periodically examine the current PSW. If
the PSW instruction address always has the same value, or if the instruction
address has a series of repeating values, the program probably is looping.
The wait state is also difficult to recognize when at the terminal. If your pro­
gram is taking longer than expected to execute, the virtual machine may be in a
wait state. Display the current PSW on the terminal. Periodically, issue the CP command QUERY TIME
and compare the elapsed processing time. When the elapsed processing time
does not increase, the wait state probably exists.
Figure 61 helps you to identify problem types and the areas where they may
occur.
Once the type of problem is identified, its cause must be determined. There are
recommended procedures to follow. These procedures are helpful, but do not
identify the cause of the problem in every case. Be resourceful. Use whatever
data you have available. If the cause of the problem is not found after the
recommended debugging procedures are followed, it may be necessary to
undertake the tedious job of desk-checking.
The section "How To Use VM/SP Facilities To Debug" describes procedures
to follow in determining the cause of various problems that can occur in the
Control Program or in the virtual machine. See the VM / SP eMS User's Guide
for information on using VM/SP facilities to debug a problem program.
If it becomes necessary to apply a Program Temporary Fix (PTF) to a VM/370 or VM/SP component, refer to the VM / SP Installation Guide for detailed
information on applying PTFs. Figure 62 , Figure 63, and Figure 64 summa­
rize the debugging process from identifying the problem to finding the cause.