Tips and tricks for better multicore parallel performance from your Haskell.
Which GHC version to use
The recommended version of GHC for parallel programming at the moment (Apr 2009) is GHC 6.12 (aka the HEAD branch of GHC), which has had extensive tuning.
Using n-1 cores
GHC has parallel garbage collection since 2007 already. However, recent work showed that this parallel GC sometimes hampers performance, based on various factors, in particular on Linux systems. See this thread for more: http://www.haskell.org/pipermail/glasgow-haskell-users/2009-April/017050.html
Data Parallel Arrays
Tools for parallel performance tuning:
- GHC (HEAD 2009) supports a visual post-mortem analysis, and a graphical tool "ThreadScope" has been developed by Satnam Singh and others.