HP Caliper User Guide Release 5.5 (5900-2351, August 2012)

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23.9 cpu Function profile
1
[cpu_fprof_1]
2
The percentage of ITLB misses (16.6%) is higher than normal.
This may indicate a poor setting for the virtual memory
instruction page size.
3
Try adding "+pi 4M" to the application's link command.
4
Use the following Caliper command to get a source listing of
the 'hot spots' in these routines:
5
caliper report fprof
4
Improvement: What you can do to try
to improve performance in this area.
1
Description: Brief text describing what
the advice is about.
2
Rule: Name of the rule that generated
this advice.
5
Measurement: Which additional HP
Caliper measurements might yield more
information in this performance area.
3
Explanation: What this performance
area is, what the related metrics
mean, what might affect it, and so
forth.
A given piece of advice will not necessarily contain all of the above information. You can use
the Advisor --advice-details command-line option to specify which information should
be printed.
In “HP Caliper Advisor Report, with Annotations” (p. 81), the first piece of advice is lacking
explanation text, and the second piece of advice is lacking measurement text.
If any pieces of advice were excluded from the report (based on command-line options), that
information is printed at the end of the report.
Suggestions for Using the HP Caliper Advisor
Here are some suggestions for getting the most out of the Caliper Advisor:
• You can analyze measurement data from new and old versions of your application at the
same time. The HP Caliper Advisor will ignore all performance data for older versions of each
executable.
• Make only a few HP Caliper performance measurement runs to start with and let the Advisor
suggest when others are appropriate. This minimizes the number of runs and allows the Advisor
to recommend optimal options (especially sampling rates) to use when making the
measurements.
• Make all of the performance runs on the same type of system. Performance data from runs
made on incompatible systems will be ignored.
• Save each HP Caliper performance run in a separate database. This makes it easier later to
mix-and-match databases for analysis.
• When you re-run the Advisor, be sure to list all of the available, current databases: the initial
ones and all additional ones. This gives the Advisor the most performance data to work with.
• If the application program is rebuilt, then start over with new performance measurements and
new databases. The Advisor will ignore obsolete data, but doing so can slow down processing.
• If a large amount of advice is not printed due to cutoff limits, try increasing the limits to see
other relevant advice. There may be some particularly useful advice just below the cutoff.
• Codify some of your past application-specific performance analysis by writing custom rules.
This customization of the Advisor helps to catch future application performance regressions.
Suggestions for Using the HP Caliper Advisor 83