--- On Thu, 6/10/10, Don Stewart wrote:

From: Don Stewart Subject: Re: [Haskell-cafe] Problems with threading? To: "Louis Wasserman" Cc: igouy2@yahoo.com, "Haskell Café List" Date: Thursday, June 10, 2010, 11:36 AM wasserman.louis:

...

     There are 4 sets of "rankings"

so -

...

     http://shootout.alioth.debian.org/u64/program.php?test=threadring〈=ghc&      id=3

Yes, but Haskell used to be doing much better

specifically on the u64q, which

...

was why I was surprised.

Oh, indeed,

    http://shootout.alioth.debian.org/u64q/performance.php?test=threadring

Something broke.

Simon Marlow described how best to parallelize this problem extensively in:

    http://www.haskell.org/~simonmar/bib/multicore-ghc-09_abstract.html

So I'd suggest doing what he says.

In particular, use thread pinning to improve locality.

-qw -qm ? How's that going to work out when applied to the other Haskell programs?

--- On Thu, 6/10/10, Don Stewart wrote:

...

...

Simon Marlow described how best to parallelize

From: Don Stewart Subject: Re: [Haskell-cafe] Problems with threading? To: "Isaac Gouy" Cc: "Louis Wasserman" , "Haskell Café List" Date: Thursday, June 10, 2010, 12:54 PM igouy2: this problem

...

...

extensively in:

    http://www.haskell.org/~simonmar/bib/multicore-ghc-09_abstract.html

So I'd suggest doing what he says.

In particular, use thread pinning to improve locality.

-qw -qm ?

How's that going to work out when applied to the other Haskell programs?

I'm sure it does bad things to them.

Yep, earlier in the week I measured the programs using +RTS -N4 -qw -qm which is why I wonder how you would approach programs that have a mix of performance characteristics? Maybe there aren't large Haskell programs like that?