patch applied (ghc): Release some of the memory allocated to a stack when it shrinks (#2090)

[Simon Marlow]

Thu Feb 28 07:31:29 PST 2008  simonmar at microsoft.com
  * Release some of the memory allocated to a stack when it shrinks (#2090)
  When a stack is occupying less than 1/4 of the memory it owns, and is
  larger than a megablock, we release half of it.  Shrinking is O(1), it
  doesn't need to copy the stack.

    M ./includes/Block.h -9 +18
    M ./includes/Storage.h +3
    M ./rts/Schedule.c -1 +52
    M ./rts/sm/BlockAlloc.c +34
    M ./rts/sm/Storage.c +28

View patch online:
http://darcs.haskell.org/ghc/_darcs/patches/20080228153129-3ed52-b5f54dcbc60777f1994f7f91b782a2f53bbb1e73.gz