[GHC] #15665: Break up the stable pointer table

[GHC]

#15665: Break up the stable pointer table
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        Reporter:  dfeuer            |                Owner:  (none)
            Type:  feature request   |               Status:  new
        Priority:  normal            |            Milestone:  8.6.1
       Component:  Compiler          |              Version:  8.4.3
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #7670             |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by dfeuer):

 Ah.... Another option: We could make the generation lists ''doubly
 linked''. This is much less expensive than I initially thought, because
 the links are intra-block, so two can fit in one word. We then add a many-
 pushers-one-popper maintenance list running through the target pointers of
 entries marked deleted. We'd keep a similar list of blocks that need more
 than a little maintenance. Now maintenance is much more effective! So
 effective that we don't need to do it on stable pointer allocation at all,
 unless the free list is empty.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15665#comment:10>
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