On Thu, 29 Apr 2010 16:02:03 +0200, Andrei Alexandrescu
<seewebsiteforem...@erdani.org> wrote:
On 04/29/2010 06:03 AM, Petr Kalny wrote:
On Fri, 23 Apr 2010 15:23:22 +0200, Walter Bright
<newshou...@digitalmars.com> wrote:
bearophile wrote:
Walter Bright:
OCaml has a global interpreter lock which explains its behavior.
Russell
didn't know why the Haskell behavior was so bad. He allowed that it
was
possible he was misusing it.
You have just the illusion to have learned something about this.
Trying to
read too much from this single example is very wrong. A single
benchmark,
written by a person not expert in the language, means nearly nothing.
You
need at least a suite of good benchmarks, written by people that know
the
respective languages. And even then, you have just an idea of the
situation.
Fair enough, but in order to dismiss the results I'd need to know
*why* the Haskell version failed so badly, and why such a
straightforward attempt at parallelism is the wrong solution for
Haskell.
You shouldn't have to be an expert in a language that is supposedly
good at parallelism in order to get good results from it.
(Russel may or not be an expert, but he is certainly not a novice at
FP or parallelism.)
Basically, I'd welcome an explanatory riposte to Russel's results.
IIRC Haskell's problems with concurrency have roots in its 100% lazy
evaluation.
Anyone wanting more details may find this page useful:
http://www.haskell.org/haskellwiki/Research_papers/Parallelism_and_concurrency
Which specific papers are you referring to?
BTW, I wonder how current the page is. It features no paper from 2009 or
2010, one from 2008, none from 2007, and six from 2006. Of those, three
links are broken.
Andrei
Right, I couldn't find the paper, I have read about concurrency in
Haskell, there as well.
(But I hoped there might be some other useful information :o).
After more searching I located that paper at:
http://research.microsoft.com/en-us/um/people/simonpj/papers/parallel/index.htm
Runtime Support for Multicore Haskell
http://research.microsoft.com/en-us/um/people/simonpj/papers/parallel/multicore-ghc.pdf
HTH
Petr
