#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, #8224 | Differential Revisions: -------------------------------------+------------------------------------- Comment (by simonmar): I talked with @bgamari about this a bit today. What I think you're seeing in the above data is entries of *indirections*, not blackholes. Indirections and blackholes look the same, except that in a true black hole, the indirectee points to a TSO rather than a value. Looking for the cases where the indirectee is a TSO will tell you how many times we get blocked on a black hole. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9221#comment:39 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler