When `heapSizeSuggestionAuto` (-H) is set, the size of the nursery can grow continuously and never shrink, resulting in memory never being returned to the OS

Loading a big project into GHCi with +RTS -H (turned on by default in ghc-bin.cabal.in) causes the nursery size to quickly become very big:

Memory inventory:
  gen 0 blocks :  2483 blocks (   9.7 MB)
  gen 1 blocks : 2043172 blocks (7981.1 MB)
  nursery      : 2034963 blocks (7949.1 MB)
  empty pinned :  4214 blocks (  16.5 MB)
  retainer     :     0 blocks (   0.0 MB)
  arena blocks :     1 blocks (   0.0 MB)
  exec         :     0 blocks (   0.0 MB)
  GC free pool :   240 blocks (   0.9 MB)
  free         : 1864899 blocks (7284.8 MB)
  UpdRemSet    :     0 blocks (   0.0 MB)
  total        : 5949972 blocks (23242.1 MB)

Furthermore, in some circumstances it seems like the nursery doesn't seem to shrink, resulting in the memory never being returned to the OS:

Note the large difference in "Blocks size" and "live bytes". This discrepancy is entirely accounted for by the nursery.

Removing -H bounds the nursery size to the size specified by -A , and allows the memory to be returned to the OS