#14974: 2-fold memory usage regression GHC 8.2.2 -> GHC 8.4.1 compiling `mmark` package -------------------------------------+------------------------------------- Reporter: hvr | Owner: (none) Type: bug | Status: new Priority: high | Milestone: Component: Compiler | Version: 8.4.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Compile-time Unknown/Multiple | performance bug Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- I haven't had time yet to diagnose where the memory is going to, but here's how to reproduce: {{{ cabal get mmark-0.0.5.6 && cd mmark-0.0.5.6/ cat > cabal.project <<EOF packages: . package mmark ghc-options: -Rghc-timing EOF }}} Then, `cabal new-build -w ghc-8.4.1` and ``cabal new-build -w ghc-8.2.2` will respectively output {{{ Resolving dependencies... Build profile: -w ghc-8.4.1 -O1 In order, the following will be built (use -v for more details): - mmark-0.0.5.6 (lib) (first run) Configuring library for mmark-0.0.5.6.. <<ghc: 13510872 bytes, 13 GCs, 806197/1299656 avg/max bytes residency (3 samples), 4M in use, 0.001 INIT (0.000 elapsed), 0.007 MUT (0.025 elapsed), 0.018 GC (0.018 elapsed) :ghc>> Preprocessing library for mmark-0.0.5.6.. Building library for mmark-0.0.5.6.. [1 of 9] Compiling Text.MMark.Parser.Internal.Type ( Text/MMark/Parser/Internal/Type.hs, /tmp/mmark-0.0.5.6/dist- newstyle/build/x86_64-linux/ghc-8.4.1/mmark-0.0.5.6/build/Text/MMark/Parser/Internal/Type.o ) [2 of 9] Compiling Text.MMark.Parser.Internal ( Text/MMark/Parser/Internal.hs, /tmp/mmark-0.0.5.6/dist- newstyle/build/x86_64-linux/ghc-8.4.1/mmark-0.0.5.6/build/Text/MMark/Parser/Internal.o ) [3 of 9] Compiling Text.MMark.Type ( Text/MMark/Type.hs, /tmp/mmark-0.0.5.6/dist- newstyle/build/x86_64-linux/ghc-8.4.1/mmark-0.0.5.6/build/Text/MMark/Type.o ) Text/MMark/Type.hs:38:1: warning: [-Wunused-imports] The import of ‘Data.Semigroup’ is redundant except perhaps to import instances from ‘Data.Semigroup’ To import instances alone, use: import Data.Semigroup() | 38 | import Data.Semigroup | ^^^^^^^^^^^^^^^^^^^^^ [4 of 9] Compiling Text.MMark.Trans ( Text/MMark/Trans.hs, /tmp/mmark-0.0.5.6/dist- newstyle/build/x86_64-linux/ghc-8.4.1/mmark-0.0.5.6/build/Text/MMark/Trans.o ) [5 of 9] Compiling Text.MMark.Util ( Text/MMark/Util.hs, /tmp/mmark-0.0.5.6/dist- newstyle/build/x86_64-linux/ghc-8.4.1/mmark-0.0.5.6/build/Text/MMark/Util.o ) [6 of 9] Compiling Text.MMark.Render ( Text/MMark/Render.hs, /tmp/mmark-0.0.5.6/dist- newstyle/build/x86_64-linux/ghc-8.4.1/mmark-0.0.5.6/build/Text/MMark/Render.o ) Text/MMark/Render.hs:25:1: warning: [-Wunused-imports] The import of ‘Data.Semigroup’ is redundant except perhaps to import instances from ‘Data.Semigroup’ To import instances alone, use: import Data.Semigroup() | 25 | import Data.Semigroup | ^^^^^^^^^^^^^^^^^^^^^ [7 of 9] Compiling Text.MMark.Parser ( Text/MMark/Parser.hs, /tmp/mmark-0.0.5.6/dist- newstyle/build/x86_64-linux/ghc-8.4.1/mmark-0.0.5.6/build/Text/MMark/Parser.o ) [8 of 9] Compiling Text.MMark ( Text/MMark.hs, /tmp/mmark-0.0.5.6 /dist- newstyle/build/x86_64-linux/ghc-8.4.1/mmark-0.0.5.6/build/Text/MMark.o ) [9 of 9] Compiling Text.MMark.Extension ( Text/MMark/Extension.hs, /tmp/mmark-0.0.5.6/dist- newstyle/build/x86_64-linux/ghc-8.4.1/mmark-0.0.5.6/build/Text/MMark/Extension.o ) <<ghc: 89663269464 bytes, 1856 GCs, 338140365/1430147624 avg/max bytes residency (23 samples), 4130M in use, 0.000 INIT (0.000 elapsed), 58.546 MUT (62.124 elapsed), 31.536 GC (31.505 elapsed) :ghc>> <<ghc: 65387008 bytes, 50 GCs, 2189716/5047200 avg/max bytes residency (5 samples), 11M in use, 0.000 INIT (0.000 elapsed), 0.021 MUT (0.207 elapsed), 0.042 GC (0.042 elapsed) :ghc>> }}} and {{{ Resolving dependencies... Build profile: -w ghc-8.4.1 -O1 In order, the following will be built (use -v for more details): - mmark-0.0.5.6 (lib) (first run) Configuring library for mmark-0.0.5.6.. <<ghc: 13510872 bytes, 13 GCs, 806197/1299656 avg/max bytes residency (3 samples), 4M in use, 0.001 INIT (0.000 elapsed), 0.007 MUT (0.025 elapsed), 0.018 GC (0.018 elapsed) :ghc>> Preprocessing library for mmark-0.0.5.6.. Building library for mmark-0.0.5.6.. [1 of 9] Compiling Text.MMark.Parser.Internal.Type ( Text/MMark/Parser/Internal/Type.hs, /tmp/mmark-0.0.5.6/dist- newstyle/build/x86_64-linux/ghc-8.4.1/mmark-0.0.5.6/build/Text/MMark/Parser/Internal/Type.o ) [2 of 9] Compiling Text.MMark.Parser.Internal ( Text/MMark/Parser/Internal.hs, /tmp/mmark-0.0.5.6/dist- newstyle/build/x86_64-linux/ghc-8.4.1/mmark-0.0.5.6/build/Text/MMark/Parser/Internal.o ) [3 of 9] Compiling Text.MMark.Type ( Text/MMark/Type.hs, /tmp/mmark-0.0.5.6/dist- newstyle/build/x86_64-linux/ghc-8.4.1/mmark-0.0.5.6/build/Text/MMark/Type.o ) [4 of 9] Compiling Text.MMark.Trans ( Text/MMark/Trans.hs, /tmp/mmark-0.0.5.6/dist- newstyle/build/x86_64-linux/ghc-8.4.1/mmark-0.0.5.6/build/Text/MMark/Trans.o ) [5 of 9] Compiling Text.MMark.Util ( Text/MMark/Util.hs, /tmp/mmark-0.0.5.6/dist- newstyle/build/x86_64-linux/ghc-8.4.1/mmark-0.0.5.6/build/Text/MMark/Util.o ) [6 of 9] Compiling Text.MMark.Render ( Text/MMark/Render.hs, /tmp/mmark-0.0.5.6/dist- newstyle/build/x86_64-linux/ghc-8.4.1/mmark-0.0.5.6/build/Text/MMark/Render.o ) [7 of 9] Compiling Text.MMark.Parser ( Text/MMark/Parser.hs, /tmp/mmark-0.0.5.6/dist- newstyle/build/x86_64-linux/ghc-8.4.1/mmark-0.0.5.6/build/Text/MMark/Parser.o ) [8 of 9] Compiling Text.MMark ( Text/MMark.hs, /tmp/mmark-0.0.5.6 /dist- newstyle/build/x86_64-linux/ghc-8.4.1/mmark-0.0.5.6/build/Text/MMark.o ) [9 of 9] Compiling Text.MMark.Extension ( Text/MMark/Extension.hs, /tmp/mmark-0.0.5.6/dist- newstyle/build/x86_64-linux/ghc-8.4.1/mmark-0.0.5.6/build/Text/MMark/Extension.o ) <<ghc: 89663269464 bytes, 1856 GCs, 338140365/1430147624 avg/max bytes residency (23 samples), 4130M in use, 0.000 INIT (0.000 elapsed), 58.546 MUT (62.124 elapsed), 31.536 GC (31.505 elapsed) :ghc>> <<ghc: 65387008 bytes, 50 GCs, 2189716/5047200 avg/max bytes residency (5 samples), 11M in use, 0.000 INIT (0.000 elapsed), 0.021 MUT (0.207 elapsed), 0.042 GC (0.042 elapsed) :ghc>> hvr@duo:/tmp/mmark-0.0.5.6$ cabal new-build -w ghc-8.2.2 Resolving dependencies... Build profile: -w ghc-8.2.2 -O1 In order, the following will be built (use -v for more details): - mmark-0.0.5.6 (lib) (first run) Configuring library for mmark-0.0.5.6.. <<ghc: 11200976 bytes, 11 GCs, 853349/1518976 avg/max bytes residency (3 samples), 5M in use, 0.001 INIT (0.000 elapsed), 0.017 MUT (0.037 elapsed), 0.021 GC (0.021 elapsed) :ghc>> Preprocessing library for mmark-0.0.5.6.. Building library for mmark-0.0.5.6.. [1 of 9] Compiling Text.MMark.Parser.Internal.Type ( Text/MMark/Parser/Internal/Type.hs, /tmp/mmark-0.0.5.6/dist- newstyle/build/x86_64-linux/ghc-8.2.2/mmark-0.0.5.6/build/Text/MMark/Parser/Internal/Type.o ) [2 of 9] Compiling Text.MMark.Parser.Internal ( Text/MMark/Parser/Internal.hs, /tmp/mmark-0.0.5.6/dist- newstyle/build/x86_64-linux/ghc-8.2.2/mmark-0.0.5.6/build/Text/MMark/Parser/Internal.o ) [3 of 9] Compiling Text.MMark.Type ( Text/MMark/Type.hs, /tmp/mmark-0.0.5.6/dist- newstyle/build/x86_64-linux/ghc-8.2.2/mmark-0.0.5.6/build/Text/MMark/Type.o ) [4 of 9] Compiling Text.MMark.Trans ( Text/MMark/Trans.hs, /tmp/mmark-0.0.5.6/dist- newstyle/build/x86_64-linux/ghc-8.2.2/mmark-0.0.5.6/build/Text/MMark/Trans.o ) [5 of 9] Compiling Text.MMark.Util ( Text/MMark/Util.hs, /tmp/mmark-0.0.5.6/dist- newstyle/build/x86_64-linux/ghc-8.2.2/mmark-0.0.5.6/build/Text/MMark/Util.o ) [6 of 9] Compiling Text.MMark.Render ( Text/MMark/Render.hs, /tmp/mmark-0.0.5.6/dist- newstyle/build/x86_64-linux/ghc-8.2.2/mmark-0.0.5.6/build/Text/MMark/Render.o ) [7 of 9] Compiling Text.MMark.Parser ( Text/MMark/Parser.hs, /tmp/mmark-0.0.5.6/dist- newstyle/build/x86_64-linux/ghc-8.2.2/mmark-0.0.5.6/build/Text/MMark/Parser.o ) [8 of 9] Compiling Text.MMark ( Text/MMark.hs, /tmp/mmark-0.0.5.6 /dist- newstyle/build/x86_64-linux/ghc-8.2.2/mmark-0.0.5.6/build/Text/MMark.o ) [9 of 9] Compiling Text.MMark.Extension ( Text/MMark/Extension.hs, /tmp/mmark-0.0.5.6/dist- newstyle/build/x86_64-linux/ghc-8.2.2/mmark-0.0.5.6/build/Text/MMark/Extension.o ) <<ghc: 89565902800 bytes, 2004 GCs, 225836231/772393000 avg/max bytes residency (27 samples), 2179M in use, 0.001 INIT (0.000 elapsed), 58.237 MUT (61.472 elapsed), 25.823 GC (25.795 elapsed) :ghc>> <<ghc: 79930048 bytes, 56 GCs, 3522920/10072040 avg/max bytes residency (6 samples), 20M in use, 0.001 INIT (0.000 elapsed), 0.028 MUT (0.213 elapsed), 0.059 GC (0.059 elapsed) :ghc>> }}} Consequently, - GHC 8.2.2: **2179M in use**, 0.001 INIT (0.000 elapsed), 58.237 MUT (61.472 elapsed), 25.823 GC (25.795 elapsed) - GHC 8.4.1: **4130M in use**, 0.000 INIT (0.000 elapsed), 58.546 MUT (62.124 elapsed), 31.536 GC (31.505 elapsed) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14974> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler