Intel® Advisor Help

Run Threading Perspective from Command Line

Threading perspective includes several steps that you are recommended to run one by one:

  1. Collect performance metrics and find candidates for parallelizing using a Survey analysis.

  2. Annotate manually loops/functions to model parallelization for.

  3. Model parallel design options and estimate speedup for the annotated loops using a Suitability analysis.

  4. Check for loop-carried dependencies to make sure the loops/functions are safe to parallelize.

Prerequisites

Set Intel Advisor environment variables with an automated script to enable the advisor command line interface (CLI).

Note

In the commands below, the options in square brackets ([--<option>]) are recommended if you want to change what data is collected.

Run Threading Perspective

  1. Run the Survey analysis:

    advisor --collect=survey --project-dir=<project-dir> -- <target-application> [<target-options>]

  2. Run the Characterization analysis to collect trip counts and/or FLOP data:

    advisor --collect=tripcounts --project-dir=<project-dir> [--flop] [--stacks] -- <target-application> [<target-options>]

    where:

    • --flop is an option to collect data about floating-point and integer operations, memory traffic, and mask utilization metrics for AVX-512 platforms.

    • --stacks is an option to enable advanced collection of callstack data.

  3. View the Survey report to identify candidates for parallelization. For example, run the following command to print the report in command line:

    advisor --report=survey --project-dir=<project-dir>

    Consider analyzing loops/functions with high total time.

  4. In the application source code, annotate loops/functions of interest to model parallelization for. Rebuild the application.

  5. Run the Suitability analysis for the annotated loops/functions:

    advisor --collect=suitability --project-dir=<project-dir> -- <target-application> [<target-options>]

  6. Run the Dependencies analysis to check for loop-carried dependencies in the annotated loops:

    advisor --collect=dependencies --project-dir=<project-dir> [--filter-reductions] -- <target-application> [<target-options>]

    where:

    • --filter-reductions is an option to mark all potential reductions with a specific diagnostic.

See advisor Command Line Interface Reference for more options.

Example

Run the Survey, Trip Counts, Suitability, and Dependencies analyses assuming you have annotated the loops.

advisor --collect=survey --project-dir=./advi -- myApplication
advisor --collect=tripcounts --project-dir=./advi --flop --stacks -- myApplication
advisor --collect=suitability --project-dir=./advi -– myApplication
advisor --collect=dependencies --project-dir=./advi --filter-reductions -– myApplication

View the Results

Intel Advisor provides several ways to work with the Threading results.

View Results in CLI

You can print the results collected in the CLI and save them to a .txt, .csv, or .xml file.

Run the following command:

advisor --report=<analysis-type> --project-dir=<project-dir> --format=<format>

where:

If you generate the Suitability report, you can use additional options to control the result view:

See advisor Command Line Interface Reference for more options.

For example, to generate the Suitability report for the OpenMP* threading model:

advisor --report=suitability --project-dir=./advi -–threading-model=openmp

You should see a similar result:

Target CPU Count: 8     Threading Model: OpenMP*
Maximum gain for all sites: 6.10998

All Sites
Site Label      Source Location       Impact to    Total Serial Time   Total Parallel Time   Site Gain   Average Serial Time   Average Parallel Time   Number of
                                      Program Gain                                                                                                     Instances 
__________________________________________________________________________________________________________________________________________________________________
     solve   nqueens_serial.cpp:154          6.11x            4.080s                0.631s       6.47x                4.080s                  0.631s           1


Site Details
Annotation     Annotation Label      Source Location       Number of Instances   Maximum Instance   Average Serial    Minimum Instance    Total Serial 
                                                                                 Time               Time              Time                Time
__________________________________________________________________________________________________________________________________________________________________
Selected Site             solve   nqueens_serial.cpp:154                     1             4.080s           4.080s              4.080s          4.080s
         Task          setQueen   nqueens_serial.cpp:156                    14             0.477s           0.267s              0.020s          3.734s
         Lock                                           ?                365596            < 0.001s         < 0.001s            < 0.001s        0.100s



Site Options
                                         Benefit   Loss If
Site            Option           Done?   If Done   Not Done   Recommended
_________________________________________________________________________
solve     Reduce Site Overhead                                      No
solve     Reduce Task Overhead                                      No
solve     Reduce Lock Overhead                                      No
solve   Reduce Lock Contention             0.16x                    No
solve     Enable Task Chunking                                      No

The result is also saved into a text file advisor-survey.txt located at <project-dir>/eNNN/hsNNN.

Note

You can also generate a report with the data from all analyses run and save it to a CSV file with the --report=joined action as follows:

advisor --report=joined --report-output=<path-to-csv>

where --report-output=<path-to-csv> is a path and a name for a .csv file to save the report to. For example, /home/report.csv. This option is required to generate a joined report.

See CPU and Memory Metrics for more information about the metrics reported.

View Results in GUI

When you run Intel Advisor CLI, a project is created automatically in the directory specified with --project-dir. All the collected results and analysis configurations are stored in the .advixeproj project, that you can view in the Intel Advisor.

To open the project in GUI, you can run the following command:

advisor-gui <project-dir>

Note

If the report does not open, click Show Result on the Welcome pane.

You first see a Threading Summary report that includes the overall information about loops/functions performance in your code and the annotated parallel sites:

Threading summary report

Save a Read-only Snapshot

A snapshot is a read-only copy of a project result, which you can view at any time using the Intel Advisor GUI. To save an active project result as a read-only snapshot:

advisor --snapshot --project-dir=<project-dir> [--cache-sources] [--cache-binaries] -- <snapshot-path>

where:

  • --cache-sources is an option to add application source code to the snapshot.

  • --cache-binaries is an option to add application binaries to the snapshot.

  • <snapshot-path is a path and a name for the snapshot. For example, if you specify /tmp/new_snapshot, a snapshot is saved in a tmp directory as new_snapshot.advixeexpz. You can skip this and save the snapshot to a current directory as snapshotXXX.advixeexpz.

To open the result snapshot in the Intel Advisor GUI, you can run the following command:

advisor-gui <snapshot-path>

You can visually compare the saved snapshot against the current active result or other snapshot results.

Next Steps

Continue to model threading results. For details about the metrics reported, see CPU and Memory Metrics.

See Also