Olivier Galibert <galibert(a)pobox.com> writes:
> On Thu, Apr 30, 1998 at 02:31:27AM +0200, Hrvoje Niksic wrote:
> > I don't think minimal tagbits should be default, because I don't see
> > any good reasons to make them so before the new dumper is written.
> *mumble*. I'm going to go and write it if it continues that way.
Please do! You'll be our hero. :-)
> > Yes, performance is equivalent (although I don't remember any actual
> > study), but memory usage is not. Minimal tagbits consume more memory
> > for conses. This will be fixed by Kyle's dumper, which will not dump
> > free lists.
> Do you mean "lists the garbage collector freed but for which free()
> didn't give the memory bakc to the system" ?
Yup. I am referring to some tests run by Kyle. She tried to estimate
how much more memory XEmacs spends with minimal tagbits (it spends
more memory because conses are lrecords, thus requiring an
lrecord_header per each cons struct), and counted additional 400K of
memory in a new XEmacs. However, most of that memory came from the
free lists which the old dumper dumped with the temacs executable.
> > 31-bit integers are nice, but they are hardly that important to a
> > normal user. Even so, the configure option is documented in NEWS, so
> > the interesting parties will be able to test it.
> I just remembered a thing. (point) being a integer, it limits the
> maximum size of a buffer to 8Mb, right ?
Wrong. More like 128M. The 8M problem has been solved a long time
ago. And while I accede that 1G is better than 128M, 128M is
> > Removing the old code is an even worse idea. While I personally
> > prefer the code with less #ifdef's, being able to run regression tests
> > is *crucial*. With the new dumper in place, it will be even more
> > important for tracking dumper bugs.
> What prevents from running regression tests ?
If you remove the old code, there is no more "let's compile this with
maximal tagbits and see if the bug repeats." Currently we can do that
Hrvoje Niksic <hniksic(a)srce.hr> | Student at FER Zagreb, Croatia
By any chance, have you seen a summoned 9th order fire elemental
wandering around? No? Oh.. Tell me if you do.