Duration Measurement Examples; Prefetch And Recursion Considerations; Figure 4-4. Prefetch Correction - HP 64700 Series User Manual

Duration
Measurement
Examples
4-30 Performance Measurements
The measurements for each label are printed in descending order
according to the amount of activity. You can see that the
"math_library" function has the most activity. Also, you can see
that no activity is recorded for several of the functions. The
histogram portion of the report compares the activity in the
functions that account for at least 1% of the activity for all labels
defined in the measurement.
Before you perform duration measurements, you should be aware
of the prefetch and recursion considerations associated with these
measurements.

Prefetch and Recursion Considerations

When using the SPMT to perform duration measurements, there
should be only two addresses stored in the trace memory: the entry
address, and the exit address. Prefetches or recursion can place
several entry addresses before the first exit address, and/or several
exit addresses before the first entry address. Duration
measurements are made between the last entry address in a series
of entry addresses, and the last exit address in a series of exit
addresses (see figure 4-4). All of the entry and exit addresses which
precede these last addresses are assumed to be unused prefetches,
and are ignored during time measurements.
START - unused prefetch
START - unused prefetch
START - unused prefetch
START - START actually taken -
END - unused prefetch
END - unused prefetch
END - unused prefetch
END - END actually taken
START - unused prefetch
START - unused prefetch
START - unused prefetch
START - START actually taken -
END - unused prefetch
END - unused prefetch

Figure 4-4. Prefetch Correction

Measure duration
-
Measure duration