gtpm1m40TPF V4R1 Migration Guide: 3.1 to 4.1

Using the Program Event Recording (PER) Trace Facility

This section discusses how to use the program event recording (PER) trace facility.

Running Virtual Machine (VM) Program Event Recording

If you are running VM instruction (PER) trace on 24-bit file-resident programs, you may experience addressing problems (the SVM address may not be the same as the EVM address, which you need for tracing). To run PER on these programs, you need to temporarily reallocate them as common.

To Temporarily Reallocate Programs as Common before Running PER

  1. Before you reallocate the program, enter the ZDPAT prog (where prog is the program name) command to determine how the program is currently allocated.
  2. To change the allocation to common, enter the ZAPAT prog CLASS-COMMON command.
  3. Re-IPL the TPF 4.1 system so that the PAT is updated.
  4. Run PER trace.
  5. Change the allocation back to what it was before you ran PER (using the ZAPAT command again)
  6. Re-IPL the TPF 4.1 system.

Running Program Event Recording (PER) in a Native TPF 4.1 System

You can run the program event recording (PER) trace facility in a native TPF 4.1 system. However, you should be careful when you use the PER trace facility on a production system because it can seriously affect system performance.

The following PER functions are supported for the TPF 4.1 system:

Note:
In a test environment under an IBM Virtual Machine (VM) system, use of the CP TRACE facility is recommended. The functions of the PER trace facility that are provided in the TPF 4.1 system is a subset of the ESA PER capability, and PER interrupts do not stop execution of the TPF 4.1 system. In addition, the CP Trace Facility is functionally more productive.

To Run PER in a Native TPF 4.1 System

  1. Use the ZSPER command to activate, end, and display the status of the PER trace facility of IBM ESA processors.
  2. Use the PER user exit to change the output destination and the amount of output or the format of output captured by a PER interrupt.