#10717: fannkuch-redux allocations increase 10000% between 7.4.2 and 7.6.3 -------------------------------------+------------------------------------- Reporter: bgamari | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.12.1 Component: Compiler | Version: 7.6.3 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Runtime Unknown/Multiple | performance bug Test Case: | Blocked By: Blocking: | Related Tickets: Differential Revisions: | -------------------------------------+------------------------------------- In a recent look at [http://home.smart-cactus.org/~ben/nofib.html historical] nofib trends I noticed that fannkuck-redux appears to regress an almost unbelievable amount in its allocations, == 7.6.3 == {{{ <<ghc: 870987952 bytes, 1668 GCs (1666 + 2), 0/0 avg/max bytes residency (0 samples), 84640 bytes GC work, 1M in use, 0.00 INIT (0.00 elapsed), 2.43 MUT (2.43 elapsed), 0.00 GC (0.00 elapsed), 0.00 GC(0) (0.00 elapsed), 0.00 GC(1) (0.00 elapsed), 1 balance :ghc>> }}} == 7.4.2 {{{ <<ghc: 74944 bytes, 1 GCs (0 + 1), 0/0 avg/max bytes residency (0 samples), 3512 bytes GC work, 1M in use, 0.00 INIT (0.00 elapsed), 2.25 MUT (2.25 elapsed), 0.00 GC (0.00 elapsed), 0.00 GC(0) (0.00 elapsed), 0.00 GC(1) (0.00 elapsed), 1 balance :ghc>> }}} Given that [FoldrBuildNotes] suggests that this test is quite sensitive to fusion, I suspect something broke here. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10717> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler