#9221: (super!) linear slowdown of parallel builds on 40 core machine -------------------------------------+------------------------------------- Reporter: carter | Owner: Type: bug | Status: new Priority: high | Milestone: 7.12.1 Component: Compiler | Version: 7.8.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: #910 | Differential Revisions: -------------------------------------+------------------------------------- Comment (by simonmar): @ezyang: I absolutely agree. Parallelism within a single process is always going to be harder to scale than separate processes. That said, there might still be low-hanging fruit (e.g. better default heap settings) for parallel compilation. I very much like `-j` in GHCi though - we cut the time to load a large project by 3x just by turning on `-j` in GHCi with some suitable heap settings (`-A256m`). -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9221#comment:25 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler