Advanced High Performance Computing Cluster Practice

Brief Introduction to Intel® VTune™ Profilers

There are some scripts in test for your reference.

Below are some frequently-used code snippets.

Set up envrionment variables

# If module is available
module load vtune
# Generally, $PATH_TO_VTUNE would be `/opt/intel/oneapi/latest/vtune` or `$HOME/intel/oneapi/vtune/latest`
. $PATH_TO_VTUNE/setvars.sh

Intel® VTune™ Amplifier’s Application Performance Snapshot

Generate results

APS would first create a directory containing results. By default, the directory would be named after date and time. It could be specified through --result-dir=$RESULT_DIR optionally.

# w/o MPI
aps $APPLICATION $APPLICATION_PARAMETERS
# w/ MPI
$MPI_LAUNCHER $MPI_PARAMETERS aps $APPLICATION $APPLICATION_PARAMETERS
# w/ Intel MPI, alternatively
$IMPI_LAUNCHER $IMPI_PARAMETERS -aps $APPLICATION $APPLICATION_PARAMETERS

Convert result to report

Then, we need obtain the analysis report (in HTML) based on the result data.

aps-report $RESULT_DIR

To open the HTML report, we could start web brower like FireFox via X11 forwarding. Alternatively, in the light of the latency, we could also start a simple web server at the directory temporally. For instance, this could be realized with Python's inbuilt http.server:

# Make sure you `cd` to the directory containing the report
python3 -m http.server

And now, we could open browser locally and enter $IP_OR_HOSTNAME:8000 to the address bar. Don't forget to close the server with Ctrl + C.

Intel® VTune™ Amplifier

Note: in some old documents, vtune & vtune-gui were amplxe & amplxe0-gui, respectively.

Collect data

Common available collect options:

• Hotspots (hotspots)
• Memory Consumption (memory-consumption)
• Microarchitecture Exploration (uarch-exploration)
• Memory Access (memory-access)
• Threading (threading)
• HPC Performance Characterization (hpc-performance)
• I/O (io)

# w/o MPI
vtune -collect $COLLECT_OPTION -r $RESULT_DIR $APPLICATION $APPLICATION_PARAMETERS
# w/ MPI
$MPI_LAUNCHER $MPI_PARAMETERS vtune -collect $COLLECT_OPTION -r $RESULT_DIR $APPLICATION $APPLICATION_PARAMETERS
# w/ Intel MPI, sample specific ranks only (This is of help since we may need sample the lowest ranks)
$IMPI_LAUNCHER $IMPI_PARAMETERS -gtool "vtune -collectt $COLLECT_OPTION -r $RESULT_DIR: $RANKS" $APPLICATION $APPLICATION_PARAMETERS

View the report

We could open the GUI directly on the remote machine with vtune-gui $RESULT_DIR via X11 forwarding. Nevertheless, due to the almost unacceptable latency, we might have installed VTune™ locally, downloading the result directory and investigating the report in local.

There is a more feasible solution. We could run the vtune-backend on the remote machine, and it would work as a web server.

vtune-backend --allow-remote-access --data-directory $PARENT_DIR_TO_RESULT_DIRS

Subsequently, we could open browser in local and enter the IP address (or hostname) and the port to the address bar. For the first time, you may need set up a password.