bug#64735: 29.0.92; find invocations are ~15x slower because of ignores

[Eli Zaretskii]

> Date: Sun, 10 Sep 2023 04:30:24 +0300
> Cc: luangruo@yahoo.com, sbaugh@janestreet.com, yantar92@posteo.net,
>  64735@debbugs.gnu.org
> From: Dmitry Gutov <dmitry@gutov.dev>
> 
> On 08/09/2023 09:35, Eli Zaretskii wrote:
> > I think you'd need to expose consing_until_gc to Lisp, and then you
> > can collect the data from Lisp.
> 
> I can expose it to Lisp and print all three from post-gc-hook, but the 
> result just looks like this:
> 
> gc-pct 0.1 gc-thr 800000 cugc 4611686018427387903
> 
> Perhaps I need to add a hook which runs at the beginning of GC? Or of 
> maybe_gc even?

You could record its value in a local variable at the entry to
garbage_collect, and the expose that value to Lisp.

> Alternatively, (memory-use-counts) seems to retain some counters which 
> don't get erased during garbage collection.

Maybe using those will be good enough, indeed.

> And as for MS Windows, IIRC all find-based solution are currently slow 
> equally, so we're unlikely to make things worse there anyway.

I was actually thinking about *BSD and macOS.