#13586: ghc --make seems to leak memory -------------------------------------+------------------------------------- Reporter: MikolajKonarski | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Resolution: | Keywords: Operating System: Linux | Architecture: x86_64 Type of failure: Compile-time | (amd64) performance bug | Test Case: Blocked By: | Blocking: Related Tickets: #13379 #13564 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by MikolajKonarski): Just one more data point, showing (I guess) how big .hi files loaded into memory and never freed can lock up lots of RAM during compilation: this commit https://github.com/LambdaHack/LambdaHack/commit/9adc5ee93ab32a9a1ba949362371... lowers maximum resident set size of GHC during compilation from 4.5G to 2.8G, as measured with `/usr/bin/time -v cabal build -j1`on Ubuntu with GHC 8.4.3. As reported in other comments, it's also the case that interrupting the compilation and then restarting it lowers resident set size considerably. Before the commit, two RAM usage peaks coincide when compiling the library section of the .cabal file --- one peak from 120 large .hi files loaded into memory (I guess ~2G) and another from an excessive amount of specialisations performed when compiling a single module that provides a concrete implementation of a certain monad. The commit just moves the specialization to executable section of the .cabal file thus separating the peaks. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13586#comment:10 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler