[GHC] #7674: Separate StablePtr table from StableName table.

[GHC]

#7674: Separate StablePtr table from StableName table.
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Reporter:  EyalLotem         |          Owner:  EyalLotem                             
    Type:  task              |         Status:  patch                                 
Priority:  normal            |      Component:  Runtime System                        
 Version:  7.6.2             |       Keywords:  rts stable_ptr stable_name performance
      Os:  Unknown/Multiple  |   Architecture:  Unknown/Multiple                      
 Failure:  None/Unknown      |      Blockedby:                                        
Blocking:                    |        Related:                                        
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Comment(by EyalLotem):

 As an interesting reference point, this benchmark is doing 10 million
 insertions of unboxed ints to boxed ints and then destruction of the hash
 table.

 The small_hash benchmark, which inserts 10 million unboxed ints to unboxed
 ints takes 0.39sec.

 It does bulk allocations of the hash nodes, which is hard to do in the FFI
 binding because the allocation happens in general-purpose code, so it
 should support releasing back memory.

 The 1.2 sec is about a factor of 3 of overhead which may be reasonable
 given the extra indirection due to stable ptrs, the int boxing and the
 more fine-grained allocation.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7674#comment:4>
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