The program is attached in this mail, along with stack & cabal config. The machine is an old T400 with an Intel dual core. Followin some advice, I checked the output of `+RTS -s` and apparently sometimes one of the sparks is fizzled which is what causes the unexpected behaviour ________________________________ From: Haskell-Cafe on behalf of Johannes Waldmann Sent: Tuesday, January 17, 2017 3:56 PM To: haskell-cafe@haskell.org Subject: Re: [Haskell-cafe] Control.Parallel seemingly randomly behaviour Hi Juan, I am interested in this because I use Control.Parallel in teaching currently. But - * what is your actual Main program / main function (it was not included in your message?) * what is your actual cabal / stack config file? * on what machine (OS, CPU) are you running this (it seems pretty slow)? * have you looked at eventlogs with threadscope? - J. _______________________________________________ Haskell-Cafe mailing list To (un)subscribe, modify options or view archives go to: http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe Haskell-Cafe Info Pagehttp://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe mail.haskell.org This mailing list is for the discussion of topics related to Haskell. The volume may at times be high, as the scope is broader than the main Haskell mailing list. Only members subscribed via the mailman list are allowed to post.