Daniel Fischer wrote:
The programme consumed more and more memory (according to top), kswapd started to have a higher CPU-percentage than my programme, programme died, system yelling 'Speicherzugriffsfehler', top displays 'kswapd<defunct>'. I believe that means my programme demanded more memory than I have available (only 256MB RAM + 800MB swap). Is that a segfault or what is the correct term?
That is probably due to (apart from the stupidity of my IO-code) the large overhead of Haskell lists.
Most certainly not. I'm pretty sure this is to a bug in your code. Something retains a data structure which is actually unneeded. Probably a case of "foldl" where "foldl'" should be used or a "try" in Parsec code where it should be left out or a lot of "updateWiths" to a Map, etc. Or it could be a bad choice of data structure. I bet, it's the map you're using to represent the graph (which you don't even need to represent at all, btw).
So the chunk of the file which easily fits into my RAM in ByteString form is too large as a list of ordinary Strings.
The chunk of file should never need to fit into RAM. If that's a problem, you also forgot to prime a crucial "foldl". Udo. -- "Proof by analogy is fraud." -- Bjarne Stroustrup