[GHC] #14193: Add RTS flag to disable 1TB address space allocation

[GHC]

#14193: Add RTS flag to disable 1TB address space allocation
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        Reporter:  nh2               |                Owner:  (none)
            Type:  feature request   |               Status:  patch
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.0.2
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #9706, #14192     |  Differential Rev(s):  Phab:D3929
       Wiki Page:                    |
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Comment (by simonmar):

 We didn't measure the effect of making it runtime-selectable. You're
 welcome to try measuring it, but my concern is that it's likely to be
 around 1% overall, and that's at the level where we care, but it's
 difficult to measure accurately given the benchmarks and tools we have.
 nofib almost certainly won't be able to measure it, because most of the
 programs in there don't do much GC.  You can try nofib/parallel, but those
 tend to be a bit noisy.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14193#comment:7>
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