[Haskell-cafe] Sparks created, but not used (par/pseq, ST monad)

Michael Lesniak mlesniak at uni-kassel.de
Fri Feb 5 03:00:05 EST 2010

Hello Daniel,

>> and running with
>>     ./st +RTS -N -s
> You'd need to give a number of capacities, I think (-N2 e.g.).
The runtime option -N chooses the maximum number of cores,  according
to GHC's documentation.

> I think with the strict ST monad, when you have
>    a <- f n1
>    b <- f n2
> they are already evaluated, so there's no point in sparking evaluation in
> parallel.
Very good point and probably the reason for my problems, thanks!


Dipl.-Inf. Michael C. Lesniak
University of Kassel
Programming Languages / Methodologies Research Group
Department of Computer Science and Electrical Engineering

Wilhelmshöher Allee 73
34121 Kassel

Phone: +49-(0)561-804-6269

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