bug#45898: 27.1; wedged in redisplay again

[Eli Zaretskii]

> From: Gerd Möllmann <gerd.moellmann@gmail.com>
> Date: Fri, 1 Jul 2022 13:04:28 +0200
> Cc: monnier@iro.umontreal.ca,
>  larsi@gnus.org,
>  psainty@orcon.net.nz,
>  Emacs-hacker2018@jovi.net,
>  45898@debbugs.gnu.org
> 
> > What kind of information is this capable to display?
> > 
> > If it's useful, we could have this script in the repository somewhere.
> 
> Good question, I'm exploring this right now.
> 
> The only way one can look at the result of the trace is, AFAICT, using the 
> GUI app Instruments.  I'll send a screenshot to everyone except debbugs in a 
> separate mail, because I don't know if debbugs can swallow that.  Does it?

It does (unless the image is very large, I think).

> In the GUI, one can see the heaviest time consumers (% execution time, and 
> time in seconds).  One can see call stacks for them, narrow down on parts of 
> call stack.  The rest I'm trying to figure out myself.

Looks and sounds useful.

> Big downside is not being able to produce some form of sharable text or pdf 
> output.

I'm sure there is some way of producing text from an image, nowadays.
But even if just the image is posted, it provides useful information.

> What would be a good place for such a script in the repo?  Does admin/macos 
> sound right?  But I'll wait for your okay for that.

I think nextstep/ is a better place.  admin/ is for stuff useful only
to Emacs developers, whereas this script sounds like being more
generally useful.