[Haskell-cafe] uvector package appendU: memory leak?
manlio_perillo at libero.it
Sun Mar 29 16:56:15 EDT 2009
Manlio Perillo ha scritto:
> As with a previous post, I think I have found a possible memory problem
> with the uvector package.
> I have this data structure (for, again, my Netflix Prize project):
> IntMap (UArr (Word16 :*: Word8))
> Today I have rewritten my program to use `alter` and `snocU`:
> append Nothing = Just $ singletonU (a :*: b)
> append (Just u) = Just $ snocU u (a :*: b)
> alter append k m
> Unfortunately I'm still not able to load the entire Netflix Prize
> training data set, grouping ratings by customers, because my PC has only
> 2 GB of RAM.
> The required memory is about 2 GB, but when the system start to swap, I
> have to kill the program.
Just another small strictness hint:
append (Just u) = u `seq` Just $ snocU u (a :*: b)
and now memory usage is 955 MB.
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