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

[Eli Zaretskii]

> Cc: Spencer Baugh <sbaugh@janestreet.com>, 64735@debbugs.gnu.org
> From: sbaugh@catern.com
> Date: Sat, 22 Jul 2023 10:42:06 +0000 (UTC)
> 
> Ihor Radchenko <yantar92@posteo.net> writes:
> > Spencer Baugh <sbaugh@janestreet.com> writes:
> >
> >> - we could use our own recursive directory-tree walking implementation
> >> (directory-files-recursively), if we found a nice way to pipe its output
> >> directly to grep etc without going through Lisp.  (This could be nice
> >> for project-files, at least)
> >
> > May you elaborate this idea?
> 
> One of the reasons directory-files-recursively is slow is because it
> allocates memory inside Emacs.  If we piped its output directly to grep,
> that overhead would be removed.

How can you do anything in Emacs without allocating memory?