Trace framework code

Trace framework code#

Tracing framework code allows you to gain insights into what happens at runtime when LUE performs work. This can help when optimizing the code.

Here is a quick list of the steps:

  1. Configure an HPX build to use APEX, e.g.:

    -D HPX_WITH_APEX=TRUE -D HPX_WITH_FETCH_APEX=TRUE

    See also CMakeHPXPresets which contains a hpx_relwithdebinfo_configuration section inherited by CMake presets for building a suitable HPX version for tracing.

  2. Add annotations to your code, using lue::AnnotateFunction. For an example, see clump.hpp

  3. Request APEX to dump trace information, by setting one or more environment variables or using the apex_exec program: https://uo-oaciss.github.io/apex/quickstarthpx

  4. If it works, dumping trace info in a format that is importable by Perfetto can be especially useful (https://ui.perfetto.dev/). It doesn’t always seem to work, though.

See also: