bug#43389: 28.0.50; Emacs memory leaks

[Eli Zaretskii <eliz@gnu.org>]

> Date: Tue, 15 Sep 2020 19:54:18 +0200
> From: Russell Adams <RLAdams@AdamsInfoServ.Com>
> 
> htop says my emacs RSS is now 5148MB. I ran M-x garbage-collect and it ran
> at 100% cpu for 5 minutes and released nothing. I also tried manually
> executing (clear-image-cache) and nothing.

Can you use some utility that produces a memory map of an application,
and see how much of those 5GB are actually free for allocation by
Emacs?  Also, do you see any libraries used by Emacs that have high
memory usage?

> I run Emacs 27.1 as a daemon, uptime 4 days, 3 hours, 22 minutes, 53
> seconds. Yesterday conki was reporting Emacs at 28% memory usage,
> today it's at 33%.

28% and 33% of what amount?

If your RSS is 5GB after 4 days of uptime, and the memory footprint
grows at a constant rate, it would mean more than 1GB per day.  But
I'm guessing that 33% - 28% = 5% of your total memory is much less
than 1GB.  In which case the memory footprint must sometimes jump by
very large amounts, not grow slowly and monotonically each day.
Right?  So which events cause those sudden increases in RSS?

Also, what is your value of gc-cons-threshold, and do you have some
customizations that change its value under some conditions?  If so,
please tell the details.

Thanks.