bug#43389: 28.0.50; Emacs memory leaks using hard disk all time

[Trevor Bentley <trevor@trevorbentley.com>]

Eli Zaretskii <eliz@gnu.org> writes:

> Just to see if we have some problem there, I left an otherwise 
> idle Emacs with 20 timer functions firing every second run 
> overnight.  It gained less than 1MB of memory footprint after 10 
> hours.  So timers alone cannot explain the dramatic increase in 
> memory footprints described in this bug report, although they 
> might be a contributing factor when the Emacs process already 
> has lots of memory allocated to it. 

Something else worth noting is that I have dozens and dozens of 
emacs processes running at all times, and only graphical X11 
clients have had memory explosion.  Plenty of my `emacs -nw` 
instances have been open for 30+ days with heavy use, and all have 
stayed under 100MB RSS.

The most recent instance I ran is a graphical instance that I 
haven't done anything in except scroll around in a single small 
elisp file.  This one has an interesting difference in memory 
usage: the usage is large (2GB heap), but it isn't growing on its 
own.  It seems to grow by 10-20MB every time it gets X11 window 
focus, and other than that it's stable.  If I alt-tab to it 
continuously, I can force its usage up.  It appears to be 
permanent.  This differs from my emacs-slack instances, which 
constantly grow even when backgrounded.

I have yet another graphical instance that I just opened and 
minimized, and never focus.  It's still only using 70MB after over 
a week.  So at least it's not simply leaking all the time... some 
active use has to trigger it.

I'll have an mtrace for you from the current experiment (X11 focus 
leak) tomorrow or Monday.  I hope it's the same issue.

-Trevor