[gclist] Re: finding object prefix from infix pointer
Fri, 9 Jul 1999 12:14:15 -0700
On Jul 9, 1:56pm, David Chase wrote:
> [ Replying semi-redundantly ... ]. The conservative
> collector uses BIBOP, or Big Bag of Pages, so the page containing
> an object determines its size. (See earlier messages on this subject).
> At one time, power-of-two sizes were used, but I am not sure if that
> is still the case.
It now uses a somewhat adaptive technique. If an allocation request is of a
size that's no smaller than, or not sufficiently close to (say within 20%), an
existing size class, it tries to create a size class corresponding exactly to
that allocation request, enforcing some minimum spacing from the next smaller
I know that integral powers of 2 are not a good idea. But I have no idea
whether this semi-adaptive technique actually helps.