[GHC] #698: GHC's internal memory allocator never releases memory back to the OS

[GHC]

#698: GHC's internal memory allocator never releases memory back to the OS
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    Reporter:  guest             |        Owner:  igloo           
        Type:  bug               |       Status:  new             
    Priority:  low               |    Milestone:  6.12 branch     
   Component:  Runtime System    |      Version:  6.4.1           
    Severity:  normal            |   Resolution:                  
    Keywords:                    |   Difficulty:  Moderate (1 day)
    Testcase:  N/A               |           Os:  Linux           
Architecture:  Unknown/Multiple  |  
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Comment (by simonmar):

 Jeremy - I think what you're describing here is not related to freeing of
 memory in the RTS.  The virtual memory used by the trivial program is
 mostly shared libraries.  Try `cat /proc/<pid>/maps` - on my x86_64/Linux
 system here, the trivial program without `-threaded` needs 16MB of VM, and
 with `-threaded` needs 20MB.  The shared library mappings account for most
 of the 16MB, and the extra 4MB with `-threaded` is due to the OS threads
 which seem to reserve 2MB each.  GHC's RTS has only allocated 1MB in each
 case, and there is no memory to free back to the OS.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/698#comment:14>
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