haskell: tune generic-builder for more parallel build performance

Raise the maximum number of cores used for parallel building from 4 to 16.
Increase the size of the allocation area for GHC's garbage collector from 1 MiB
to 64 MiB.

See https://www.twitch.tv/videos/611899011 for the motivation for this change.
This commit is contained in:
Peter Simons 2020-05-07 12:48:51 +02:00
parent 0d9dbeef23
commit ccb81f56cf

View file

@ -48,12 +48,8 @@ in
, isExecutable ? false, isLibrary ? !isExecutable
, jailbreak ? false
, license
# We cannot enable -j<n> parallelism for libraries because GHC is far more
# likely to generate a non-determistic library ID in that case. Further
# details are at <https://github.com/peti/ghc-library-id-bug>.
#
# Currently disabled for aarch64. See https://ghc.haskell.org/trac/ghc/ticket/15449.
, enableParallelBuilding ? ((stdenv.lib.versionOlder "7.8" ghc.version && !isLibrary) || stdenv.lib.versionOlder "8.0.1" ghc.version) && !(stdenv.buildPlatform.isAarch64)
# aarch64 sometimes crashes for -jn with n>1: https://ghc.haskell.org/trac/ghc/ticket/15449
, enableParallelBuilding ? !stdenv.buildPlatform.isAarch64
, maintainers ? []
, doCoverage ? false
, doHaddock ? !(ghc.isHaLVM or false)
@ -82,7 +78,7 @@ in
# same package in the (recursive) dependencies of the package being
# built. Will delay failures, if any, to compile time.
allowInconsistentDependencies ? false
, maxBuildCores ? 4 # GHC usually suffers beyond -j4. https://ghc.haskell.org/trac/ghc/ticket/9221
, maxBuildCores ? 16 # more cores usually don't improve performance: https://ghc.haskell.org/trac/ghc/ticket/9221
, # If set to true, this builds a pre-linked .o file for this Haskell library.
# This can make it slightly faster to load this library into GHCi, but takes
# extra disk space and compile time.
@ -181,6 +177,8 @@ let
(optionalString enableHsc2hsViaAsm "--hsc2hs-option=--via-asm")
];
parallelBuildingFlags = "-j$NIX_BUILD_CORES" + optionalString stdenv.isLinux " +RTS -A64M -RTS";
crossCabalFlagsString =
stdenv.lib.optionalString isCross (" " + stdenv.lib.concatStringsSep " " crossCabalFlags);
@ -199,7 +197,7 @@ let
"--package-db=$packageConfDir"
(optionalString (enableSharedExecutables && stdenv.isLinux) "--ghc-option=-optl=-Wl,-rpath=$out/lib/${ghc.name}/${pname}-${version}")
(optionalString (enableSharedExecutables && stdenv.isDarwin) "--ghc-option=-optl=-Wl,-headerpad_max_install_names")
(optionalString enableParallelBuilding "--ghc-option=-j$NIX_BUILD_CORES")
(optionalString enableParallelBuilding "--ghc-options=${parallelBuildingFlags}")
(optionalString useCpphs "--with-cpphs=${cpphs}/bin/cpphs --ghc-options=-cpp --ghc-options=-pgmP${cpphs}/bin/cpphs --ghc-options=-optP--cpp")
(enableFeature (enableDeadCodeElimination && !stdenv.hostPlatform.isAarch32 && !stdenv.hostPlatform.isAarch64 && (versionAtLeast "8.0.1" ghc.version)) "split-objs")
(enableFeature enableLibraryProfiling "library-profiling")
@ -227,9 +225,9 @@ let
setupCompileFlags = [
(optionalString (!coreSetup) "-${nativePackageDbFlag}=$setupPackageConfDir")
(optionalString (isGhcjs || isHaLVM || versionOlder "7.8" ghc.version) "-j$NIX_BUILD_CORES")
# https://github.com/haskell/cabal/issues/2398
(optionalString (versionOlder "7.10" ghc.version && !isHaLVM) "-threaded")
(optionalString enableParallelBuilding (parallelBuildingFlags))
"-threaded" # https://github.com/haskell/cabal/issues/2398
"-rtsopts" # allow us to pass RTS flags to the generated Setup executable
];
isHaskellPkg = x: x ? isHaskellLibrary;