Changes between Version 45 and Version 46 of WikiStart


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Timestamp:
Jun 19, 2012, 3:58:18 AM (12 years ago)
Author:
Ben Lippmeier
Comment:

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  • WikiStart

    v45 v46  
    3535Q: Why is my program so slow? [[br]]
    3636A: Probably because you haven't forced your source arrays before traversing them, or haven't added enough INLINE pragmas. In particular you may need to force image arrays read with the BMP routines before traversing them. Read [http://www.haskell.org/haskellwiki/Numeric_Haskell:_A_Repa_Tutorial#Optimising_Repa_programs the optimisation section] in the tutorial, then [http://stackoverflow.com/questions/6300428/poor-performance-with-transpose-and-cumulative-sum-in-repa/6340867#6340867 This Answer] on Stack Overflow. If it's still a problem then continue on...
     37
     38Q: Why does the runtime so much from run to run? [[br]]
     39A: Maybe because you haven't enabled thread affinity and some threads are being swapped out by the OS. Enable thread affinity with {{{+RTS -qa}}}. Disabling the parallel garbage collector in generation 0 may also help {{{+RTS -qg}}}.
    3740
    3841Q: Where do I ask further questions? [[br]]