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Chapter 7: Making Software Performance Measurements
To use the Software Performance Measurement Tool
The SPMT makes its duration measurements from the last start address in the series
of start addresses, to the last end address in the series of end addresses. The other
start and end addresses are unused prefetches and are ignored by the software of the
SPMT. Recursive procedures will still affect the accuracy of your measurements.
The prefetch correction has the following consequences:
•
Prefetches are ignored. They do not affect the accuracy of the measurement in
process.
•
When measuring a recursive function, module duration will be measured
between the last recursive call and the true end of the recursive execution. This
will affect the accuracy of the measurement.
•
If a module is entered at the normal point, and then exited by a point other than
the defined exit point, the entry point will be ignored. It will be judged the
same as any other unused prefetch, and no time-duration measurement will be
made. Its time will be included in the measure of time spent outside the
procedure or function.
•
If a module is exited from the normal point, and then reentered from some
other point, the exit will also be assumed to be an unused prefetch of the exit
state.
If you are making duration measurements on a function that is recursive, or one that
has multiple entry and/or exit points, the result may be invalid information.
To use the Software Performance Measurement
Tool
Activity and duration measurements are made with the SPMT in a five-step
process, summarized as follows:
1 Set up the trace command.
2 Initialize the performance measurement.
3 Run the performance measurement.
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