#8611: nofib’s cacheprof’s allocations nondeterminisitic -------------------------------------+------------------------------------- Reporter: nomeata | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: NoFib benchmark | Version: 8.5 suite | 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 sgraf): Some notes from my Windows machine: - In the default build configuration with `-O2`, allocations are completely stable. Maximum residency is unstable, though. - The instability in max residency goes away if I do similar surgically `seq`s as above. - In `-O0`, I even get unstable allocations on Windows, with the samples spread wider than on Linux the other day. - In `-O0 -prof -fprof-auto` there's still a seldom, minimal instability of 40 bytes delta - Judging from `+RTS -S` output, the culprit seems to be an errorneous life set. Comparing two reports from different runs, there was always a point at which the live bytes differed and only much later total bytes allocated would differ. I had a sample where the difference was 1488 bytes in (minor) collection no. 11. These allocations seem to be kept live until the end of the program, and more live data is added during the run of the program. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8611#comment:9 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler