Subject: Re: bug#65908: 29.1.50; Emacs 29 regresses on macOS

From: Gerd Möllmann <[email-masked]>
Date: Wed, 04 Oct 2023 07:44:33 +0200

Zhang Haijun <[email-masked]> writes:

> 1 emacs -Q
> 2 paste the following code to scratch buffer and execute it for saveral times
>
> (benchmark-progn 
>   (setq enable-dir-local-variables nil
>             enable-local-variables nil)
>
>   (let* ((test-dir "~/source/emacs-git/lisp")
>              (file-list (directory-files test-dir t
>                                                        "\\`[fsw].*[.]el\\'" t))
>              (start-tm (current-time))
>              end-tm buf buf-list)
>
>       (dolist (test-file file-list)
>         (setq buf (find-file-noselect test-file))
>         (with-current-buffer buf
>             (goto-char (point-min))
>             (while (not (eobp))
>               (end-of-defun)))
>         (setq buf-list (cons buf buf-list)))
>
>       (setq end-tm (current-time))
>
>       (dolist (buf buf-list)
>         (kill-buffer buf))
>
>       (let ((delta (time-subtract end-tm start-tm)))
>         (message "--- files: %d, delta: %s"
>                      (length file-list) (float-time delta)))))

(Your mailer does strange things with whitespace...)

> Time used in Emacs 29 is 1.6x than in Emacs 27. They are all built with "-O2".
> I also tested on Linux. There is no such big regress.

Thanks for the report.

I can reproduce this on macOS 14.0 (OCLP).

emacs-28, HEAD:
"--- files: 61, delta: 3.086468"
"--- files: 61, delta: 3.106478"
"--- files: 61, delta: 3.325344"

emacs-29, HEAD:
"--- files: 61, delta: 5.052421"
"--- files: 61, delta: 5.068663"
"--- files: 61, delta: 5.110502"

FWIW, master
"--- files: 61, delta: 5.124109"
"--- files: 61, delta: 5.101217"
"--- files: 61, delta: 5.13068"