#15938: Hadrian's recompilation check is extremely slow -------------------------------------+------------------------------------- Reporter: bgamari | Owner: (none) Type: bug | Status: new Priority: high | Milestone: 8.8.1 Component: Build System | Version: 8.6.2 (Hadrian) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by bgamari): Putting aside the GC strangeness for a bit, it still seems like Hadrian is rather slow to start. The 12 second mutator time during start-up is still rather sluggish. The profile shows the following: {{{ Thu Nov 29 17:59 2018 Time and Allocation Profiling Report (Final) hadrian +RTS -I0 -qg -l -s -p -A32M -RTS --lint --directory /home/ben/ghc/ghc total time = 16.60 secs (16598 ticks @ 1000 us, 1 processor) total alloc = 26,405,461,216 bytes (excludes profiling overheads) COST CENTRE MODULE SRC %time %alloc unionWith General.TypeMap src/General/TypeMap.hs:34:1-97 37.1 53.2 ?== Development.Shake.Internal.FilePattern src/Development/Shake/Internal/FilePattern.hs:(226,1)-(230,34) 32.3 10.4 split Data.List.Extra src/Data/List/Extra.hs:(569,1)-(571,48) 15.5 20.6 getUserRuleInternal Development.Shake.Internal.Core.Rules src/Development/Shake/Internal/Core/Rules.hs:(62,1)-(75,48) 3.1 2.2 foldr Data.ByteString.UTF8 Data/ByteString/UTF8.hs:(171,1)-(173,40) 2.6 4.1 defaultRuleFile Development.Shake.Internal.Rules.File src/Development/Shake/Internal/Rules/File.hs:(191,1)-(194,96) 1.6 0.0 decode Data.ByteString.UTF8 Data/ByteString/UTF8.hs:(68,1)-(124,32) 1.4 5.4 &%> Development.Shake.Internal.Rules.Files src/Development/Shake/Internal/Rules/Files.hs:(163,1)-(180,42) 1.1 0.7 }}} Is this what you would expect during start-up, ndmitchell? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15938#comment:14 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler