On Sat, Aug 27, 2011 at 5:25 AM, Brandon Moore
I'm confused by this as well. Parallelizing --make was one of the first case studies in the smp runtime paper, section 7 in Haskell on a Shared-Memory Multiprocessor
There's also a trac ticket http://hackage.haskell.org/trac/ghc/ticket/910with a vague comment that the patch from the paper "almost certainly isn't ready for prime time", but I haven't seen any description of specific problems.
From what I remember someone tried to parallelize GHC but it turned out to me tricky in practice. At the moment very trying to parallelize Cabal which would allow us to build packages/modules in parallel using ghc -c and let Cabal handle dependency management (including preprocessing of .hsc files).
Johan