Re: [Haskell-cafe] Control.Parallel.Strategies
Out of interest, have you tried using parListChunk to break the work into larger pieces? It seems rather unlikely to help with this case as the parts are already pretty large, but perhaps it's worth a shot. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Control.Parallel.Strategies
On Fri, Apr 11, 2008 at 10:43 AM, Don Stewart <[EMAIL PROTECTED]> wrote: > sebastian.sylvan: > >On Wed, Apr 9, 2008 at 10:58 PM, Justin Bailey <[EMAIL PROTECTED] > > > >wrote: > > > > On Wed, Apr 9, 2008 at 2:25 PM, Sebastian Sylvan > > <[EMAIL PROTECTED]> wrote: > > > Nope! > > > > > > This is GHC 6.8.2 btw, downloaded the binary from the web site, > so > > it's > > > nothing strange. > > > > On my hyper-threaded CPU, your original code works fine. With -N2, > I > > see 100% CPU. With N1, only 50%. I am also using GHC [3]6.8.2. > > Justin > > > >Hmm, that's curious. I compile with "ghc --make -threaded partest.hs > -o > >par.exe", and then run it with "par.exe +RTS -N2 -RTS". Am I making > some > >silly configuration error? > >Are you running this on windows? > > > > I think its always worth using -O or -O2 too, for what its worth. > Yes I've tried both, neither helped. -- Sebastian Sylvan +44(0)7857-300802 UIN: 44640862 ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Control.Parallel.Strategies
sebastian.sylvan: >On Wed, Apr 9, 2008 at 10:58 PM, Justin Bailey <[EMAIL PROTECTED]> >wrote: > > On Wed, Apr 9, 2008 at 2:25 PM, Sebastian Sylvan > <[EMAIL PROTECTED]> wrote: > > Nope! > > > > This is GHC 6.8.2 btw, downloaded the binary from the web site, so > it's > > nothing strange. > > On my hyper-threaded CPU, your original code works fine. With -N2, I > see 100% CPU. With N1, only 50%. I am also using GHC [3]6.8.2. > Justin > >Hmm, that's curious. I compile with "ghc --make -threaded partest.hs -o >par.exe", and then run it with "par.exe +RTS -N2 -RTS". Am I making some >silly configuration error? >Are you running this on windows? > I think its always worth using -O or -O2 too, for what its worth. -- Don ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Control.Parallel.Strategies
On Wed, Apr 9, 2008 at 11:10 PM, Justin Bailey <[EMAIL PROTECTED]> wrote: > On Wed, Apr 9, 2008 at 3:03 PM, Sebastian Sylvan > <[EMAIL PROTECTED]> wrote: > > Hmm, that's curious. I compile with "ghc --make -threaded partest.hs -o > > par.exe", and then run it with "par.exe +RTS -N2 -RTS". Am I making some > > silly configuration error? > > Are you running this on windows? > > Yep, that's the command line I used and I am running XP. > > Justin > That is indeed weird. The only difference seems to be that you have hyperthreading, whereas I have dual cores. But as I mentioned, manual parallelism works (using forkIO)... -- Sebastian Sylvan +44(0)7857-300802 UIN: 44640862 ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Control.Parallel.Strategies
On Wed, Apr 9, 2008 at 3:03 PM, Sebastian Sylvan <[EMAIL PROTECTED]> wrote: > Hmm, that's curious. I compile with "ghc --make -threaded partest.hs -o > par.exe", and then run it with "par.exe +RTS -N2 -RTS". Am I making some > silly configuration error? > Are you running this on windows? Yep, that's the command line I used and I am running XP. Justin ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Control.Parallel.Strategies
On Wed, Apr 9, 2008 at 10:58 PM, Justin Bailey <[EMAIL PROTECTED]> wrote: > On Wed, Apr 9, 2008 at 2:25 PM, Sebastian Sylvan > <[EMAIL PROTECTED]> wrote: > > Nope! > > > > This is GHC 6.8.2 btw, downloaded the binary from the web site, so it's > > nothing strange. > > On my hyper-threaded CPU, your original code works fine. With -N2, I > see 100% CPU. With N1, only 50%. I am also using GHC 6.8.2. > > Justin > Hmm, that's curious. I compile with "ghc --make -threaded partest.hs -o par.exe", and then run it with "par.exe +RTS -N2 -RTS". Am I making some silly configuration error? Are you running this on windows? -- Sebastian Sylvan +44(0)7857-300802 UIN: 44640862 ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Control.Parallel.Strategies
On Wed, Apr 9, 2008 at 2:25 PM, Sebastian Sylvan <[EMAIL PROTECTED]> wrote: > Nope! > > This is GHC 6.8.2 btw, downloaded the binary from the web site, so it's > nothing strange. On my hyper-threaded CPU, your original code works fine. With -N2, I see 100% CPU. With N1, only 50%. I am also using GHC 6.8.2. Justin ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Control.Parallel.Strategies
On Wed, Apr 9, 2008 at 10:22 PM, Justin Bailey <[EMAIL PROTECTED]> wrote: > 2008/4/9 Sebastian Sylvan <[EMAIL PROTECTED]>: > > main = print $ parMap rnf fib $ take 80 $ randomRs (30,35) (mkStdGen > 123) > > Does the strategy "rwhnf" do it for you? > > Justin > Nope! This is GHC 6.8.2 btw, downloaded the binary from the web site, so it's nothing strange. -- Sebastian Sylvan +44(0)7857-300802 UIN: 44640862 ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Control.Parallel.Strategies
2008/4/9 Sebastian Sylvan <[EMAIL PROTECTED]>: > main = print $ parMap rnf fib $ take 80 $ randomRs (30,35) (mkStdGen 123) Does the strategy "rwhnf" do it for you? Justin ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Control.Parallel.Strategies
Hi, I was toying with the Control.Parallel.Strategies library, but can't seem to get it to actually do anything in parallel! Here's the code: import System.Random import Control.Parallel.Strategies fib :: Int -> Int fib 0 = 1 fib 1 = 1 fib n = fib (n-1) + fib (n-2) main = print $ parMap rnf fib $ take 80 $ randomRs (30,35) (mkStdGen 123) I compile with "-threaded", and run with +RTS -N2 -RTS, but yet it stays at 50% on my dual core machine! I should point out that any manual threading with forkIO does indeed use 100% of the CPU, and this problem happens on my work computer too (Vista on my home computer, XP on the work one). Anything I'm missing here? Thanks, -- Sebastian Sylvan +44(0)7857-300802 UIN: 44640862 ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
