Ideally I'd like to put GHC in a debugging mode were the first time a
#9221: (super!) linear slowdown of parallel builds on 40 core machine -------------------------------------+------------------------------------- Reporter: carter | Owner: Type: bug | Status: new Priority: normal | Milestone: 8.2.1 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 Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by bgamari): thread blocks on a black hole the program crashes with a stack trace ;-). Edit rinse repeat until they're all gone. You may be interested in Phab:D1216, which builds on the the DWARF-based statistical profiling support that I have [[DWARF/80Status|in the works]] for provide profiling of black-hole entry events. As-written this patch only captures the head of the stack, although this could be changed to provide a deeper stacktrace. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9221#comment:52 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler