[GHC] #8732: Global big object heap allocator lock causes contention

[GHC]

#8732: Global big object heap allocator lock causes contention
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        Reporter:  tibbe                    |            Owner:  simonmar
            Type:  bug                      |           Status:  new
        Priority:  normal                   |        Milestone:  7.10.1
       Component:  Runtime System           |          Version:  7.6.3
      Resolution:                           |         Keywords:
Operating System:  Unknown/Multiple         |     Architecture:
 Type of failure:  Runtime performance bug  |  Unknown/Multiple
       Test Case:                           |       Difficulty:  Unknown
        Blocking:                           |       Blocked By:
                                            |  Related Tickets:
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Comment (by simonmar):

 It's even harder than that, because a block can be allocated by one thread
 and freed by another thread, so we lose block coalescing, even if it can
 be made to work safely.

 So I suggest if we want to do anything at all here, we just do the really
 simple thing: we allocate a chunk of contiguous memory, keep it in the
 capability, and use that to satisfy large block requests if it's large
 enough.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8732#comment:10>
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