Use this command to change or display the program event recording (PER)
options online. These options are used to display status, and activate
and deactivate the hardware PER facility of an Enterprise Systems Architecture
(ESA) processor.
Requirements and Restrictions
- Only one of the supported PER functions can be active at a time.
- You should be extremely careful when using the PER facility on a
production system because it can seriously affect system performance.
Format
- Display
- displays information that indicates whether or not the PER facility is
active.
- Store Into
- traces PER storage alteration events.
- Branch Into
- traces successful PER branching events. This parameter is valid
only for ESA/390 processors.
- Instruct Range
- traces PER instruction fetching events.
- address
- is the 1- to 8-digit hexadecimal storage address to be monitored.
- bytes
- is the 1- to 8-digit hexadecimal number of bytes to be monitored.
Address wrap-around is not supported.
- Data-match
- processes the PER interrupt only if the instruction at the PER interrupt
address matches the specified data, where match is the 2- to 16-digit
hexadecimal data. Intervening blanks are not allowed.
- Note:
- The PER interrupt count is incremented regardless of the result of the
comparison.
- Printer-name
- sends the output to the specified device, where name is the 1- to
8-character alphanumeric device name. Intervening blanks are not
allowed. The default device is the read-only (RO) computer room agent
set (CRAS).
- Note:
- The value specified for this parameter is passed with the PER interrupt data
to the UPER real-time user exit. You must create the program
necessary to support the specified device.
- End
- stops the PER facility.
Additional Information
- Online help information is available for this command. To display
the help information, enter one of the following:
ZSPER HELP
ZSPER ?
- A PER interrupt provides the instruction address used to fetch the current
instruction when a PER event is recognized. When the instruction is the
target of EXECUTE, the instruction address used to fetch the EXECUTE
instruction is provided.
- In a test environment under VM, use the CP TRACE facility. The PER
facility that is provided by the TPF system is a subset of the ESA PER
capability and PER interrupts do not stop the operation of the TPF
system.
- ESA/370 processors provide PER storage alteration and instruction fetching
functions in the TPF system.
- ESA/390 processors provide PER storage alteration, instruction fetching,
and branching functions support in the TPF system.
- z/Architecture support processors provide PER storage alteration,
instruction fetching, and branching functions support in the TPF
system.
- The PER facility is automatically stopped if more than 10 PER interrupts
are received in any 10-second interval.
Examples
The following example monitors PER branches into addresses
X'1A480'-X'1A485'.
+--------------------------------------------------------------------------------+
|User: ZSPER BRANCH INTO-1A480.6 |
| |
|System: SPER0002I 09.20.20 PER TRACE STARTED |
+--------------------------------------------------------------------------------+
The following example stops the PER facility.
+--------------------------------------------------------------------------------+
|User: ZSPER END |
| |
|System: SPER0003I 09.30.06 PER TRACE ENDED |
+--------------------------------------------------------------------------------+
Related Information
See TPF Program Development Support Reference or
ESA/390 Principles of Operation for more
information about the program event recording (PER) facility.