bug#36597: 27.0.50; rehash hash tables eagerly in pdumper

[Pip Cet]

On Sun, Jul 21, 2019 at 5:34 AM Pip Cet <pipcet@gmail.com> wrote:
> On Sun, Jul 21, 2019 at 3:18 AM Paul Eggert <eggert@cs.ucla.edu> wrote:
> > Pip Cet wrote:
> > > I'm currently playing around with redefining hash tables not to have
> > > internal freelists. That makes the hash table code a lot simpler
> > > overall, but some of that simplicity would be lost trying to support
> > > lazy hash table rehashing.
> >
> > While looking into this I discovered unlikely bugs in Emacs's hash table 
> > code
> > and GC that can make Emacs dump core, along with some other unlikely 
> > hash-table
> > bugs that can cause Emacs to report memory exhaustion when there should be
> > plenty of memory. I installed the attached patches to fix these problems 
> > and to
> > refactor to make this code easier to understand (at least for me :-). These
> > patches will probably affect performance analysis.
>
> Well, at least they'll require rebasing, particularly of the
> no-internal-freelists patch :-)

Rebased patches attached. The performance measurements don't seem to
change significantly.

> While your changes are extensive, I don't see anything in there that
> would drastically affect performance or memory footprint. Maybe I'm
> missing something, though.

0001-Rehash-hash-tables-eagerly-after-loading-a-dump.patch
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0001-snapshot.patch.gz
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