[Haskell-cafe] Slow mvar when compiled with threaded

[Branimir Maksimovic]

On 01/07/2014 09:39 PM, Bob Ippolito wrote:
> Here's a much simpler implementation for that sort of pattern, using 
> channels to fan out work to threads. I added a dependency on Criterion 
> because getCPUTime is basically useless for this kind of measurement 
> on Mac OS X since it doesn't include the time that the process spent 
> waiting on IO:
Great, thank you very much. You gave me material for learning ;)
However, my version is significantly faster when compiling without 
-threaded.
With -threaded option, your version is much faster than mine, but both 
are significantly slower
then compile without -threaded.

Thanks!