On Wednesday 22 May 2002 12:48 pm, Hal Daume III wrote:
so i have a function that is eating *tons* of memory. my application is clustering and i put everything in UArrays or Arrays. for clustering 5 data points with 4 features (a tiny tiny set) the program gobbles 350mbs! most of the usage is coming from this distance function:
Ahh, a fellow memory abuser. ;) I recently ran into very similar behavior while implementing a Haskell rendering engine. I was using a lookup table deep within a loop, and references to the lookup table seemed to be allocated as each computation was deferred. I immediately allocated over 150MB for a very simple render. Try turning on heap profiling, and see if you get anything interesting. There is an option to display "named" references (or something like that) that might provide insight into what's responsible. In my case, I rewrote my monad to be stricter (and used case), and forced a result data structure to be strict in its components. This forced complete evaluation of all of the elements prior to returning the result. I don't know if you have a nice place to put something like that, but it's worth a look. When all was said and done, my application memory usage never went above 4MB, which is exactly where I expected it to be. Check out this link: http://users.aber.ac.uk/ajc99/stricthaskell.html It has some interesting ways of forcing evaluation at various times, etc., although I prefer other ways of obtaining these results. However, it is a good list of candidate changes for debugging. Enjoy! - j -- The river is moving. The blackbird must be flying.