Re: org-persist-write slow when pp-use-max-width is t

[Ihor Radchenko]

Michael Eliachevitch  writes:

> I submitted a bug report where I attached the index file and a minimal 
> example file which benchmarks running pp on it, with which I could reproduce 
> my issue from emacs -Q:
>
> https://debbugs.gnu.org/cgi/bugreport.cgi?bug=58687
>
> Let's see what the emacs devs have to say about it.

Since the slowdown has been acknowledged as a known problem to be fixed
in future, I have pushed a workaround for now.

Fixed, on bugfix.
https://git.savannah.gnu.org/cgit/emacs/org-mode.git/commit/?id=ecdb44204

-- 
Ihor Radchenko // yantar92,
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Learn more about Org mode at .
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Re: org-persist-write slow when pp-use-max-width is t

[Michael Eliachevitch]

pp-max-width has been introduced in Emacs 29.
The fact that pp becomes too slow is likely something to be fixed before
the next Emacs release.


Good catch and I agree. I compile emacs from the master branch and probably 
discovered in the emacs-news which I check between upgrades and I probably 
customized it subsequently, even though I forgot about the customization later.


While we can work around this issue on Org side, I'd prefer to ask Emacs
developers first and see if they can come up with a fix.

I suggest you to file a bug report to Emacs.
You may provide the contents of your org-persist-index-file inside
org-persist-directory. AFAIU, it is what is taking a lot of time to
print.


I submitted a bug report where I attached the index file and a minimal example 
file which benchmarks running pp on it, with which I could reproduce my issue 
from emacs -Q:

https://debbugs.gnu.org/cgi/bugreport.cgi?bug=58687

Let's see what the emacs devs have to say about it.
--
Michael Eliachevitch
Public PGP Key: 
https://keyoxide.org/hkp/546908c782383ad0e7d894ec1b8f95c8125dce31

Re: org-persist-write slow when pp-use-max-width is t

[Ihor Radchenko]

Michael Eliachevitch  writes:

> I was wondering why kill-emacs emacs takes over a minute and after some 
> profiling I found out that the call to org-persist-write-all takes long when 
> pp-use-max-width is set to t and pp-max-width is also set (in my case to t, 
> the window-width), which enables line folding in pp. The pp-call happens in 
> org-persist--write-elisp-file when it is called by org-persist-write:index 
> with the pp-parameter set to t. Maybe it's clearer with the following excerpt 
> of my CPU-profile:
>
>38009  96%  - org-persist-write-all
>38009  96%   - org-persist-write
>37703  95%- mapcar
>37703  95% - #
>37703  95%  - org-persist-write:index
>37703  95%   - org-persist--write-elisp-file
>37703  95%- pp
>37703  95% - pp-to-string
>37703  95%  - pp-emacs-lisp-code
>37687  95%   + pp--insert-lisp
>
> Setting pp-use-max-width to nil made the function call almost instantanteous.
>
> I had enabled pp-use-max-width in the past when pretty-printing the results 
> of interactive elisp sessions (like pp-eval-last-sexp). I didn't think this 
> would affect how other packages would save their data and I didn't expect 
> this would result in such a performance hit. Possibly this is not an issue 
> with org-mode or pp but just my own mistake of not being aware that pp is 
> used as a library by other packages and thus customizing its behaviour has 
> global effects.
>
> Not sure if the org mailing list is the best place to report this 
> observation. What org could do is to use a let-binding to temporarily set 
> pp-use-max-width to nil to disable line folding. Or do you think that some 
> users might care that their cache files are formatted prettily according to 
> their customization options?
>
> If you think this is not an issue with org-mode, maybe I/we could forward 
> this to the pp-maintainers, as it's in emacs core possibly to emacs-devel? I 
> think at least a warning in the variable documentation about performance hits 
> might have been helpful.

Thanks for reporting!
pp-max-width has been introduced in Emacs 29.
The fact that pp becomes too slow is likely something to be fixed before
the next Emacs release.

While we can work around this issue on Org side, I'd prefer to ask Emacs
developers first and see if they can come up with a fix.

I suggest you to file a bug report to Emacs.
You may provide the contents of your org-persist-index-file inside
org-persist-directory. AFAIU, it is what is taking a lot of time to
print.

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at .
Support Org development at ,
or support my work at