#15976: Can't run nofib in parallel -------------------------------------+------------------------------------- Reporter: sgraf | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: ⊥ Component: NoFib | Version: benchmark suite | Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- I was under the impression that `make -j$n` within `nofib` would run benchmarks in parallel, but it doesn't. The following warning is indicative: {{{ make[1]: warning: -jN forced in submake: disabling jobserver mode. }}} Whenever `make` is called recursively, any `-j` flags will lead to this warning and consequently disable parallelisation (which would lead to a number of jobs exponential in the depth of recursive calls). Parallel benchmarks are useful to get deterministic metrics such as allocations or counted instructions really fast. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15976 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler