EPTRACE Manual

EPTRACE Manual—528811-002

2-1

2 Using EPTRACE

EPTRACE allows you to determine the frequency and locations of compatibility traps

and transitions. Using this information you can resolve these problems and improve the

performance of your application code.

Before Running an EPTRACE Session

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Use a separate TACL prompt and EPTRACE session for each traced CPU.

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If your trace buffer is large enough, you can start a tracing session on a program

using one set of ETPRACE options while running another tracing session on

another program with a different set of options. This does not impact the tracing

results of either program.

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When entering commands, you can type FC at the command line to display the

previous command you typed. You can either repeat that command, or edit the

previous command and run the edited version from the command line.

Running an EPTRACE Session

1. At the TACL prompt type EPTRACE. This is an example of the startup banner:

EPTRACE - T9050H02 - (Apr 18 2005)

Current path is $SYSTEM.SYS30

Running on \HALF4 CPU 1

2. Enter the CLEAR command and the ALL option.

3. Enter the START command and the program or PIN option. For the PROGRAM

option, enter the program name you want to trace information for. This is run from

a separate TACL prompt. For the PIN option, enter the process number. If the

program is already running or is long running, find the process number (PIN) and

then use the START command to start EPTRACE in the CPU where the process is

running.

4. Run the program or programs for which you want to report trace information and

enter the START command(s). Evaluate the results using the SHOW command.

5. Enter the SHOW command and any of its appropriate options to evaluate the

traced information. Note that counters for an already terminated process may or

may not be available depending on how you have set the tracing options. Trace

items for all processes share a common buffer and entries can be lost if the buffer

wraps.

6. Enter the STOP command to stop tracing.