#16011: GHCi leaks memory even with -fno-it. -------------------------------------+------------------------------------- Reporter: AndreasK | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.6.3 Component: GHCi | Version: 8.7 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- GHCi leaks are not exactly new, but this one is especially easy to trigger/reproduce. The memory allocated by f never gets freed. {{{ PS E:\binary-perf> ..\ghc-8.6.1\bin\ghci.exe -fno-it GHCi, version 8.6.1: http://www.haskell.org/ghc/ :? for help Prelude> f = [1 .. 20000000] :: [Int] Prelude> length f 20000000 Prelude> f = [1 .. 20000001] :: [Int] Prelude> length f 20000001 Prelude> f = [1 .. 20000002] :: [Int] Prelude> length f 20000002 Prelude> f = [1 .. 20000000] :: [Int] Prelude> length f 20000000 Prelude> }}} Or using head and even simpler: {{{ PS E:\binary-perf> ..\ghc_commonAsm\inplace\bin\ghci.exe -fno-it GHCi, version 8.7.20181207: http://www.haskell.org/ghc/ :? for help Loaded package environment from E:\binary- perf\.ghc.environment.x86_64-mingw32-8.7.20181207 Prelude> f = replicate 2000000 False Prelude> length f 2000000 Prelude> f = replicate 2000000 False Prelude> length f 2000000 Prelude> f = replicate 2000000 False Prelude> length f 2000000 Prelude> f = replicate 2000000 False Prelude> length f }}} GHC just keeps using more and more memory when I repeat this. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16011 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler