Subject: bug#71644: 30.0.50; Severe slowdown in larger files with markers beginning in emacs 29+

From: Eli Zaretskii <[email-masked]>
Date: Sat, 22 Jun 2024 17:12:47 +0300

> Cc: [email-masked]
> From: Ihor Radchenko <[email-masked]>
> Date: Sat, 22 Jun 2024 13:53:08 +0000
> 
> Mitchell <[email-masked]> writes:
> 
> > Here are the steps to reproduce the issue:
> > ...
> 
> For the record, I am able to reproduce the problem using the latest
> Emacs master.
> 
> And the problem does disappear with my patch that affects the marker
> loop in src/marker.c (buf_bytepos_to_charpos)
> 
> So, markers appear to be the culprit on my system.

Not the markers, but conversion of character positions to buffer
positions.  Which uses markers, but that's an implementation detail...