Re: Motif support

[Eli Zaretskii]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Cc: Akira Kyle <akira@akirakyle.com>,  luangruo@yahoo.com,  ofv@wanadoo.es,
>   emacs-devel@gnu.org
> Date: Mon, 20 Dec 2021 14:01:52 -0500
> 
> My impression is that would be "easier" to speed things up by making use
> of multiple CPUs rather than making use of GPUs.  True concurrency when
> running ELisp is hard, but there are other ways to make use of multiple
> CPUs:
> 
> - make the GC parallel.
> - make the GC concurrent.
> - use a separate thread per window-redisplay (so when redisplaying 20
>   windows we can use 20 CPUs to update their glyph matrices).
> - ...

I think in all cases where redisplay was really slow, it was either
due to slow Lisp being called by JIT font-lock, or by very long lines
in the buffer, or both.  If we have several such windows, then yes,
having that run in parallel could speed up things, but is that really
a frequent case?

And anyway, working on several windows in parallel will have to deal
with the buffer-local stuff that changes global state, since each
window generally displays a different buffer, and the display code
makes that buffer current for the duration of time it works on a
window.