Hi, My space problems continued... :) I have some ForeignPtr's, with finalizers (finalizerFree only). And I have lazyly produced list of those (yes, there is some unsafePerformIO magic behind, but I think I got this right). The problem is I get out-of-memory condition because elements get produced faster than those consumed are garbage collected. Example: list = ... mapM_ writeOut list writeOut :: Ptr Word8 writeOut dat = do hPutBuh handle dat 1024 -- Control.Concurrent.threadDelay 1000 Uncommenting this line allows gc thread to run finalizers, memory gets freed, everything runs smoothly... As far as I know finalizers are run in separate thread. How do I increase priority of this thread so it runs faster? -- Gracjan