Re: Observing lags or never ending processes

[Eli Zaretskii]

> Date: Sun, 11 Sep 2022 15:36:02 +0300
> From: Jean Louis <bugs@gnu.support>
> Cc: help-gnu-emacs@gnu.org
> 
> Basically on invokation of a command, something starts happening in
> background, preventing command to run straight, and I know that it
> would kind of finish execution and my command would run, but it takes
> long time. Almost always I interrupt it with C-g multiple times, then
> I try again.
> 
> It can also happen during writing or normal operations. I am watching
> CPU load, so I see CPU load increasing.
> 
> Just before minutes, I was doing M-% replacement and then it finds one
> term, I answer with `y' and then it finds another one, and so on, then
> in middle of that all findings, then something starts in background,
> preventing me to do the work.

I suggest to begin by saying

  M-x set-variable RET garbage-collection-messages RET t RET

and then see if, when "something starts in the background", you see
the telltale "Garbage collecting..." message in the echo area.