[GHC] #15402: The settings and behaviour of idle GC are very confusing

[GHC]

#15402: The settings and behaviour of idle GC are very confusing
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        Reporter:  nh2               |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:  8.8.1
       Component:  Runtime System    |              Version:  8.4.3
      Resolution:                    |             Keywords:  newcomer
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by simonmar):

 Re (1), can you demonstrate it?  I just tried `ghci +RTS -S -I0` and it
 definitely disabled the idle GC. (this was with current master)

 I do see it doing two idle GCs when I would expect just one. I'm not sure
 why that is.

 Re (2) I think you might be talking about the non-threaded RTS. With the
 threaded RTS, -I0.3 is the default, with the non-threaded RTS -I0 is the
 default.  This probably needs to be documented. It probably never occurred
 to me that someone might use `-I` with the non-threaded RTS.

 For (3) yes I think the docs need to be updated.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15402#comment:2>
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