Support running tracing profiler with the application

[giordano]

We're planning to support running the applications with tracing profilers, which are generally slightly easier to deal with than those using performance counters (like linux perf, or likwid).

Some of the profilers we're considering supporting:

• Intel Vtune: proprietary, but can be used free of charge, only supports x86 architectures
• Nvidia Nsight Systems: proprietary, but can be used free of charge, supports x86 and aarch64 architectures, currently not available in Spack, supports also MPI and GPU profiling. Edit: Nvidia Nsight Systems is part of the nvhpc bundle, but that package is large. There's a PR to add a standalone package for Nsight Systems: [WIP, CI did not pass] nvidia-nsight-systems: new package spack/spack#42771 superseded by nvidia-nsight-systems: new package spack/spack#47355
• Extrae: free and open source, available on a wide range of platforms, less popular than above options, supports also MPI and GPU profiling, but not extremely simple to use (the visualisation counterpart, Paraver, is also powerful but not intuitive to use)
• Score-P: free and open-source, but I'm not familiar with it myself, can't comment more about it

[ilectra]

How about Linaro Forge? (used to be ArmForge)

[giordano]

Unlike all profilers mentioned above, linaro requires a license though, which makes it much harder to test.

[ilectra]

Sure, but we do have a licence on (at least!) DiRAC systems.

[tkoskela]

The license is paid by ExCALIBUR so it might be gone after March 👿 I can ask about this in the next H&ES meeting.

[giordano]

Note to self: in ReFrame for profilers which need to wrap the mpirun call we can use LauncherWrapper