Emacs exit is slow when auto-complete-mode is enabled

[ioah86]

I had for a while a problem that my emacs would exit in a very slow way. So I went through my .emacs file and disabled one by one different modes, until I found the culprit in auto-complete.

It appears that haveing auto-complete-mode on is causing emacs to take a while to shut down. Sometimes up to 10s, which is truly impractical. Googling showed that there is at least one more soul out there with a similar observation: https://www.reddit.com/r/emacs/comments/12bzssc/why_is_autocomplete_slowing_down_killing_emacs/

Details on my installation:

Arch Linux, Kernel 6.6.23-1-lts
Emacs 29.3
auto-complete-20240320.1734

Lines in .emacs:

(ac-config-default)
(global-auto-complete-mode t)

Please advise.

[jcs090218]

Can you try to profile it? 🤔

[ioah86]

Sure... As far as I know, there are multiple ways to profile in Emacs... If you can let me know the way you prefer to profile, and what exact files/outputs you are looking for, I am happy to do it.

[jcs090218]

Yeah, it's a bit tricky to do profiling when exiting the Emacs. Can you try disabling auto-complete before exiting emacs? You should be able to shutdown without any slow down.

[totakura]

I too am observing this emacs-29.3. I moved mv ~/.emacs/ac-comphist.dat{,.bk} and that seemed to address the slowness, albeit losing history I guess.

[ghbrown]

The culprit is ac-comphist-save(). I've tried to profile it with profiler-start and profiler-report, but I'm not getting useful results (just command-execute).