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Parallelism profiles

With Parallel Haskell programs, we usually don't care about the results -- only with "how parallel" it was! We want pretty pictures.

Parallelism profiles (a la `hbcpp') can be generated with the `-q' RTS option. The per-processor profiling info is dumped into files named `<full-path><program>.gr'. These are then munged into a PostScript picture, which you can then display. For example, to run your program `a.out' on 8 processors, then view the parallelism profile, do:

% ./a.out +RTS -N8 -q
% grs2gr *.???.gr > temp.gr     # combine the 8 .gr files into one
% gr2ps -O temp.gr              # cvt to .ps; output in temp.ps
% ghostview -seascape temp.ps   # look at it!

The scripts for processing the parallelism profiles are distributed in `ghc/utils/parallel/'.


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