#15153: GHC uses O_NONBLOCK on regular files, which has no effect, and blocks the runtime -------------------------------------+------------------------------------- Reporter: nh2 | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.6.1 Component: Runtime System | Version: 8.2.2 Resolution: | Keywords: Operating System: Linux | Architecture: Type of failure: Runtime | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by nh2): Also funny but perhaps not too surprising: If in my code, you replace `forkIO` by e.g. `forkOn 2`, then nondeterministically, sometimes the program hangs and sometimes it works with `+RTS -N2`. The higher you set `-N`, the more likely it is to work. If you put both the putStrLn loop and the readFile into `forkOn 0` and `forkOn 1` each, and run with `+RTS -N3`, then it always works as expected. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15153#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler