When profiling my Haskell program with the -hd flag, I see about 50K listed as "Trace Elements". What does this mean?

CodePudding user response：

These are additional bands in the heap graph that would be too small to display, that is, each one only contributes “trace amounts” of size to the heap, like trace chemical elements. You can adjust the threshold with the -t flag, documented in the GHC User’s Guide §8.5. hp2ps – Rendering heap profiles to PostScript:

-t⟨float⟩

Normally trace elements which sum to a total of less than 1% of the profile are removed from the profile. The -t option allows this percentage to be modified (maximum 5%).

-t0 requests no trace elements to be removed from the profile, ensuring that all the data will be displayed.