VTune profiler

-

First load an environment module:

module add vtune/XXXX

Intro:
https://www.intel.com/content/www/us/en/docs/vtune-profiler/get-started-guide/2023/linux-os.html

Help:

vtune -help

Run VTune via command line interface (recommended non-interactive use)

Run your application with VTune wrapper as follows:
www.intel.com/content/www/us/en/docs/vtune-profiler/user-guide/2023-0/command-line-interface.html

Example

mpirun -np 4 vtune –collect hotspots -result-dir vtune_hotspot ./path-to_your/app.exe args_of_your_app

After completion explore hotspot analysis e.g. via

vtune -report summary -r vtune_*

VTune-GUI (not recommended)

Login with x-window support (ssh -X) and then start

vtune-gui

Run VTune-GUI remotely on your own browser (recommended interactive use)

First, login to the supercomputer with local port forwarding and start your VTune server on an exclusive compute node (as 1h interactive job):

ssh -L 127.0.0.1:55055:127.0.0.1:55055 blogin.hlrn.de
salloc -p standard96:test -t 01:00:00
ssh -L 127.0.0.1:55055:127.0.0.1:55055 $SLURM_NODELIST
module load vtune/2022
vtune-backend --web-port=55055 --enable-server-profiling &

Second, open 127.0.0.1:55055 in your browser (allow security exception, if first time set initial password).

Under WHAT (in 1st "Welcome" tab)
-> Click: Configure Analysis
--> Application: /path-to-your-application/program.exe
--> Check: Use app. dir. as work dir.
--> Expand "Advanced": keep defaults but paste "Wrapper script:"
	#!/bin/bash
	# Prefix script
	echo "Target process PID: ${VTUNE_TARGET_PID}"
	# Run VTune collector
	mpirun -np 2 "$@"
--> Expand "Advanced"
---> keep defaults but paste "Wrapper script:"
---> Check: Trace MPI
Under HOW (in 1st "Welcome" tab)
-> Run "Performance Snapshot"
When complete (in 2nd tab r0...)
-> for overview expand: "HPC Perf. Characterization"
-> for results & to select next analysis expand: "Performance Snapshot" 
--> Click: "Hotspots"

Under HOW (in 3rd tab r0...)
-> Run "Hotspots"
When complete (after finalizing results)
--> Expand sub-tab "Top-down Tree"
---> In "Function Stack" expand "_start" fct. and expand further down to "main" fct. (first with entry under "Source File") 
---> Double click on: source_file_name.c
--> In new sub-tab "source_file_name.c" scroll down to line with max. "CPU Time: Total" to find hotspot

To quit the debug session press "Exit" in the VTune "Menu" (upper left symbol of "three horizontal bars"). Then close the browser page. Exit your compute node via CTRL+D and kill your interactive job:

squeue -l -u $USER
scancel your-job-id