#8623: Strange slowness when using async library with FFI callbacks ------------------------------+-------------------------------------------- Reporter: | Owner: simonmar JohnWiegley | Status: new Type: bug | Milestone: 7.8.1 Priority: normal | Version: 7.6.3 Component: Runtime | Operating System: MacOS X System | Type of failure: Runtime performance bug Keywords: | Test Case: Architecture: | Blocking: Unknown/Multiple | Difficulty: Unknown | Blocked By: | Related Tickets: | ------------------------------+-------------------------------------------- I've attached a Haskell and a C file, when compiled as such: ghc -DSPEED_BUG=0 -threaded -O2 -main-is SpeedTest SpeedTest.hs SpeedTestC.c You should find that with 7.4.2, 7.6.3 or a recent build of 7.8, building with SPEED_BUG=0 produces an executable that takes more than a second to run, while building with SPEED_BUG=1 runs very quickly. I've also attached the Core for both scenarios. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8623 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler