What's the status of multicore programming in Haskell?

Question

What's the status of multicore programming in Haskell? What projects, tools, and libraries are available now? What experience reports have there been?

Sidky

Answer 1

In the 2009-2012 period, the following things have happened:

2012:

• From 2012, the parallel Haskell status updates began appearing in the Parallel Haskell Digest.

2011:

• Parallel and Concurrent Programming in Haskell, a tutorial. version 1.1 released by Simon Marlow
• Haskell and parallelism, mentioned in an article in the Economist magazine, Jun 2nd 2011.
• Parallel tree scans via composition, an article by Conal Elliott
• Numeric Haskell, a tutorial on parallel array programming with Repa, released
• Works has begun on extending GHC eventlog and Threadscope to support multi-process or distributed Haskell systems
• Parallel Haskell Digest: Edition 2.
• The par-monad package and a monad for deterministic parallelism, Simon Marlow -- more control over pure parallelism than strategies/par/pseq.
• Cloud Haskell: Erlang-style message passing between distributed Haskell nodes.
• Parallel Haskell: Embracing Diversity, a talk by SPJ.
• Real time edge detection in parallel Haskell
• Parallel Haskell Digest: news on parallel Haskell
• Composable parallel scanning
• Haskell-MPI is released

2010:

• Parallel futures for Haskell, in GHC.
• The Orc language, for concurrent job scheduling and scripting, was released.
• A new scalable thread event manager was merged into GHC.
• An improved approach to parallel sparks and strategies was developed.
• The Nikola EDSL for embedding GPU programs in Haskell was developed.
• The LLVM backend for GHC was merged in, with good performance improvements.
• ghc 6.12.x series: with parallel performance improvements
• Microsoft announces 2 years of funding to support commercial users of Parallel Haskell
• Google published their experience report on the use of Haskell (PDF)
• Intel announced the Concurrent Collections for Haskell library, including scalability numbers -- scaling results for 32 and 48 cores
• Sun/Oracle bought us a machine and funded work on improving parallel performance.
• Recent updates to the status of Data Parallelism in Haskell
• MSR released ThreadScope, a graphical profiler for parallel Haskell programs
• The GHC runtime got extensively tuned for sparks and futures
• There was a good discussion on additional ways to improve parallel performance
• A collection of reading material on parallelism in Haskell to help you get started
• The Snap guys are getting 45k req/sec on their 4 way box, by using all the cores.
• Even the Erlang guys are taking notice.
• Meanwhile, there is work to make the IO manager more scalable -- now with a paper on the design :: PDF.
• We're out there teaching people too .. all .. over .. the ... place.
• Starling Software wrote about their real time, multicore financial trading system in Haskell.
• Ericsson published a parallel language for DSP based on, and written in Haskell
• Galois published an implementation of Orc, a concurrent workflow language, in Haskell.
• And a new library for fast regular, parallel arrays appeared
• And Haskell continues to do well on the quad-core shootout.
• Snap, a multicore-enabled scalable web server with great performance numbers
• haskell-torrent - benchmarking a mulitcore-enabled bittorrent client in Haskell
• Haskell code was published at Supercomputing 09 -- our first appearance at SC!

Sidky

Posted so there's a place to record the evolving answer to this common question. – Sidky

so in that case this q&a should be community-wiki (according to my understanding of SO etiquette). btw thanks for this summary – Alkyne

Is the "new scalable thread event manager" part of a GHC released version yet? – Sideband

gawi: it is part of GHC 7. The release candidate for that was put out two weeks ago. – Sidky

As far as the Computer Language Benchmarks Game goes Java 7 has pulled out ahead of Haskell. I remember Haskell doing much better a couple of years ago. Does this indicate a possible performance regression in GHC 7? – Sibilate

The "new scalable thread event manager" link appears to be broken (404) – Boaten

Looks like the "new scalable thread event manager" paper is available from research.google.com/pubs/archive/36841.pdf – Microsporangium