Re: guile/guile-core/libguile init.c

[Mikael Djurfeldt <mdj at mdj dot nada dot kth dot se>]

Jim Blandy <jimb@red-bean.com> writes:

> In his thesis, Ben Zorn recommends that one should not GC when the
> freelist is exhausted.  If you do this, then programs whose data size
> is close to the current heap size will GC very frequently, because the
> freelists will always be short.  And since these GC's will reclaim
> very little storage, the time they take is pretty much wasted.

I have implemented this scheme and comittedit to the repository.

You get it by defining

  GUILE_NEW_GC_SCHEME

in __scm.h.

It still contains bugs.  One is associated with guardians.  (I haven't
looked closely at guardians relative to this change yet.)  Please help
me find the bugs!  :-)

Two nice things:

* Guile seems to start and run faster with this change

* Heap sizes adapt themselves so that Guile automatically finds a good
  working point for the floating point benchmarks: Guile with 2-word
  cells + this change *is* faster on floating point calculations than
  old Guile!