[Haskell-cafe] Threading and Mullticore Computation

Don Stewart dons at galois.com
Tue Mar 3 12:41:44 EST 2009

> On 2009 Mar 3, at 12:31, mwinter at brocku.ca wrote:
>> In both runs the same computations are done (sequentially resp.
>> parallel), so the gc should be the same. But still using 2 cores is
>> much slower than using 1 core (same program - no communication).
> The same GCs are done, but GC has to be done on a single core  
> (currently; parallel GC is in development) so you will see a lot more  
> lock contention when the GC kicks in.

Assuming he is using GHC 6.10, the parallel GC is enabled by default
when you use -Nn where n > 1. That's is -N4 will use -g4   (4 cores to
collect). So GC should be the same or a little faster.

-- Don

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