Subject: 31.0.50; Performance issue in dired+isearch with dired-isearch-filenames

From: Ergus <[email-masked]>
Date: Wed, 21 May 2025 01:33:19 +0200

Hi:

I have been using dired and isearch in a directory with ~8000 files and
emacs became totally non-responsive. It freezed with every letter for
~10 seconds.

I checked my config and it seems that the problem is
`dired-isearch-filenames`. Any non-nil value produces this issue.

I ran with the profiler and it showed that all the time is going in
`next-single-property-change`

       86696  91% - command-execute
       86696  91%  - call-interactively
       86695  91%   - funcall-interactively
       59531  62%    - isearch-printing-char
       59531  62%     - isearch-process-search-char
       59531  62%      - isearch-process-search-string
       59531  62%       - isearch-search-and-update
       45907  48%        - isearch-update
       45890  48%         - isearch-lazy-highlight-new-loop
       45890  48%          - redisplay
       45854  48%           - timer-event-handler
       45854  48%            - apply
       45854  48%             - isearch-lazy-highlight-buffer-update
       45853  48%              - isearch-lazy-highlight-search
       45852  48%               - isearch-search-string
       45852  48%                - #<byte-code-function C84>
       45852  48%                 - apply
       45852  48%                  - search-within-boundaries
       45778  48%                   - #<byte-code-function C9F>
       45726  48%                    - mapcar
       45722  48%                     - #<byte-code-function C7B>
       45721  48%                        next-single-property-change
          35   0%                    + seq-min
           9   0%                      make-closure
           6   0%                      delq
          40   0%                   + #<byte-code-function 990>
           2   0%                   + #<byte-code-function F75>
           1   0%              + isearch-filter-visible
          36   0%             redisplay_internal (C function)
          14   0%         + pos-visible-in-window-group-p
           2   0%         + isearch-message
           1   0%         + window-max-chars-per-line
       13620  14%        + isearch-search
           4   0%        + isearch-message
       27143  28%    - isearch-del-char
       13624  14%     - isearch-update
       13624  14%      - isearch-lazy-highlight-new-loop
       13624  14%       - redisplay
       13622  14%        - timer-event-handler
       13622  14%         - apply
       13622  14%          - isearch-lazy-highlight-buffer-update
       13622  14%           - isearch-lazy-highlight-search
       13622  14%            - isearch-search-string
       13622  14%             - #<byte-code-function 511>
       13622  14%              - apply
       13622  14%               - search-within-boundaries
       13602  14%                - #<byte-code-function 500>
       13584  14%                 - mapcar
       13581  14%                  - #<byte-code-function 55A>
       13578  14%                     next-single-property-change
          10   0%                 + seq-min
           4   0%                   make-closure
           2   0%                   delq
          13   0%                + #<byte-code-function 990>
           2   0%          redisplay_internal (C function)
       13519  14%     - isearch-search
       13519  14%      - isearch-search-string
       13519  14%       - #<byte-code-function 415>
       13519  14%        - apply
       13519  14%         - search-within-boundaries
       13498  14%          - #<byte-code-function 42C>
       13486  14%           - mapcar
       13485  14%            - #<byte-code-function C2A>
       13482  14%               next-single-property-change
           5   0%             make-closure
           3   0%           + seq-min
           2   0%             delq
          12   0%          + #<byte-code-function 990>
          11   0%    + isearch-forward
           6   0%    + isearch-abort
           3   0%    + dired-next-line
           1   0%    + dired-previous-line
        7498   7% - timer-event-handler
        7498   7%  - apply
        6849   7%   - isearch-lazy-highlight-buffer-update
        6837   7%    - isearch-lazy-highlight-search
        6831   7%     - isearch-search-string
        6810   7%      - #<byte-code-function 492>
        6810   7%       - apply
        6810   7%        - search-within-boundaries
        6802   7%         - #<byte-code-function 49D>
        6793   7%          - mapcar
        6793   7%           - #<byte-code-function 7A7>
        6792   7%              next-single-property-change
           3   0%          + seq-min
           3   0%            delq
           1   0%            make-closure
           5   0%         + #<byte-code-function 990>
          15   0%      + #<byte-code-function 990>
           1   0%        char-table-p
           1   0%      + isearch-search-fun
           2   0%     + isearch-filter-visible
           9   0%    + isearch-filter-visible
           1   0%    + internal--before-save-selected-window
         638   0%   + isearch-lazy-highlight-start
           5   0%   + jit-lock-stealth-fontify
           3   0%   + show-paren-function
           3   0%   + jit-lock-context--update
         362   0% + redisplay_internal (C function)
          62   0%   Automatic GC
           8   0% + tooltip-hide
           2   0% + winner-save-old-configurations
           2   0% + undo-auto--add-boundary
           0   0%   ...

In GNU Emacs 31.0.50 (build 4, x86_64-pc-linux-gnu, GTK+ Version
 3.24.49, cairo version 1.18.4) of 2025-05-19 built on RTX
Repository revision: b499898a5e6e27ecacfb6a60b22a2289afc589dd
Repository branch: project
System Description: Arch Linux

Configured using:
 'configure --prefix=/home/ergo/.local/ --with-mailutils --with-pgtk
 --with-modules --with-cairo --with-harfbuzz
 --with-native-compilation=aot
 '--program-transform-name=s/^ctags$/ctags.emacs/''

Configured features:
ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GPM GSETTINGS HARFBUZZ JPEG
LCMS2 LIBSYSTEMD LIBXML2 MODULES NATIVE_COMP NOTIFY INOTIFY PDUMPER PGTK
PNG RSVG SECCOMP SOUND SQLITE3 THREADS TIFF TOOLKIT_SCROLL_BARS
TREE_SITTER WEBP XIM GTK3 ZLIB

Important settings:
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix

Major mode: Elisp/l

Minor modes in effect:
  windmove-mode: t
  global-auto-revert-mode: t
  recentf-mode: t
  electric-pair-mode: t
  whitespace-mode: t
  flyspell-mode: t
  completion-preview-mode: t
  diff-hl-margin-local-mode: t
  diff-hl-margin-mode: t
  diff-hl-mode: t
  global-corfu-mode: t
  corfu-mode: t
  fancy-compilation-mode: t
  winner-mode: t
  project-multi-mode: t
  gtags-mode: t
  repeat-mode: t
  xterm-mouse-mode: t
  tty-tip-mode: t
  xclip-mode: t
  override-global-mode: t
  save-place-mode: t
  delete-selection-mode: t
  savehist-mode: t
  global-display-fill-column-indicator-mode: t
  display-fill-column-indicator-mode: t
  global-display-line-numbers-mode: t
  display-line-numbers-mode: t
  which-key-mode: t
  tooltip-mode: t
  eldoc-mode: t
  show-paren-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  file-name-shadow-mode: t
  context-menu-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  minibuffer-regexp-mode: t
  size-indication-mode: t
  column-number-mode: t
  line-number-mode: t
  indent-tabs-mode: t
  transient-mark-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t

Load-path shadows:
/mnt/casa/gits/emacs_clones/gtags-mode/gtags-mode hides /home/ergo/.config/emacs/elpa/gtags-mode-1.8.6/gtags-mode
/home/ergo/.config/emacs/elpa/transient-20250516.1031/transient hides /home/ergo/.local/share/emacs/31.0.50/lisp/transient

Features:
(shadow sort mail-extr emacsbug lisp-mnt windmove jka-compr find-func
cl-print dired-subtree dired-hacks-utils dired-aux dash help-fns
radix-tree mc-edit-lines mc-hide-unmatched-lines-mode mc-mark-more
sgml-mode facemenu dom mc-cycle-cursors multiple-cursors-core advice
comp comp-cstr warnings rect autorevert filenotify recentf tree-widget
ffap thingatpt misearch multi-isearch tramp-cache time-stamp tramp-sh
tramp trampver tramp-integration tramp-message tramp-compat shell
pcomplete parse-time iso8601 format-spec tramp-loaddefs vc-git elec-pair
whitespace flyspell-correct flyspell ispell completion-preview
diff-hl-margin diff-hl-dired diff-hl log-view log-edit message sendmail
yank-media puny dired-x dired dired-loaddefs rfc822 mml mml-sec epa
derived epg rfc6068 epg-config gnus-util time-date mm-decode mm-bodies
mm-encode mail-parse rfc2231 rfc2047 rfc2045 mm-util ietf-drums
mail-prsvr mailabbrev mail-utils gmm-utils mailheader add-log pcvs-util
vc-dir ewoc vc vc-dispatcher diff-mode track-changes corfu
fancy-compilation compile text-property-search comint ansi-osc
ansi-color comp-run comp-common winner cus-edit pp cus-start cus-load
wid-edit project-multi-mode gtags-mode files-x xref project ring
term/tmux term/xterm xterm init rx repeat cape compat use-package-ensure
package browse-url xdg url url-proxy url-privacy url-expand url-methods
url-history url-cookie generate-lisp-file url-domsuf url-util mailcap
url-handlers url-parse auth-source eieio eieio-core cl-macs icons
password-cache json subr-x map url-vars use-package-diminish xt-mouse
tty-tip xclip edmacro kmacro byte-opt use-package-bind-key bind-key
cl-extra help-mode simple-16-theme saveplace delsel savehist easy-mmode
display-fill-column-indicator display-line-numbers diminish which-key
cl-seq use-package-core cl-loaddefs cl-lib bytecomp byte-compile gv
disp-table info arduino-cli-mode-autoloads auctex-autoloads tex-site
avy-zap-autoloads avy-autoloads benchmark-init-autoloads
bufferlo-autoloads caml-autoloads cape-autoloads clang-format-autoloads
cobol-mode-autoloads compile-multi-autoloads compiler-explorer-autoloads
corfu-autoloads crdt-autoloads csv-mode-autoloads d-mode-autoloads
dape-autoloads deadgrep-autoloads debbugs-autoloads diff-hl-autoloads
diminish-autoloads dired-sidebar-autoloads dired-subtree-autoloads
dired-hacks-utils-autoloads dumb-jump-autoloads e2ansi-autoloads
eglot-booster-autoloads emamux-autoloads eshell-toggle-autoloads
esup-autoloads evil-collection-autoloads annalist-autoloads
evil-leader-autoloads evil-autoloads face-explorer-autoloads
fancy-compilation-autoloads flx-autoloads flymake-nasm-autoloads
flymake-quickdef-autoloads flyspell-correct-autoloads
git-commit-ts-mode-autoloads git-modes-autoloads
git-timemachine-autoloads gnuplot-autoloads goto-chg-autoloads
groovy-mode-autoloads gtags-mode-autoloads haskell-mode-autoloads
highlight-indent-guides-autoloads i3wm-config-mode-autoloads
ibuffer-sidebar-autoloads iedit-autoloads imenu-list-autoloads
julia-ts-mode-autoloads julia-mode-autoloads languagetool-autoloads
lice-autoloads lorem-ipsum-autoloads lua-mode-autoloads magit-autoloads
magit-section-autoloads llama-autoloads move-dup-autoloads
multiple-cursors-autoloads mutt-mode-autoloads nasm-mode-autoloads
neotree-autoloads nftables-mode-autoloads nginx-mode-autoloads
notmuch-autoloads objed-autoloads phi-search-autoloads
pkgbuild-mode-autoloads plz-autoloads popup-autoloads
protobuf-ts-mode-autoloads scopeline-autoloads shell-command+-autoloads
slime-autoloads macrostep-autoloads sphinx-mode-autoloads f-autoloads
s-autoloads dash-autoloads spinner-autoloads ssh-config-mode-autoloads
string-inflection-autoloads sudo-edit-autoloads systemd-autoloads
tmux-mode-autoloads transient-autoloads urgrep-autoloads vdiff-autoloads
hydra-autoloads lv-autoloads vterm-toggle-autoloads vterm-autoloads
vundo-autoloads with-editor-autoloads xclip-autoloads
yasnippet-snippets-autoloads yasnippet-autoloads early-init rmc
iso-transl tooltip cconv eldoc paren electric uniquify ediff-hook
vc-hooks lisp-float-type elisp-mode mwheel term/pgtk-win pgtk-win
term/common-win touch-screen pgtk-dnd tool-bar dnd fontset image
regexp-opt fringe tabulated-list replace newcomment text-mode lisp-mode
prog-mode register page tab-bar menu-bar rfn-eshadow isearch easymenu
timer select scroll-bar mouse jit-lock font-lock syntax font-core
term/tty-colors frame minibuffer nadvice seq simple cl-generic
indonesian philippine cham georgian utf-8-lang misc-lang vietnamese
tibetan thai tai-viet lao korean japanese eucjp-ms cp51932 hebrew greek
romanian slovak czech european ethiopic indian cyrillic chinese
composite emoji-zwj charscript charprop case-table epa-hook
jka-cmpr-hook help abbrev obarray oclosure cl-preloaded button loaddefs
theme-loaddefs faces cus-face macroexp files window text-properties
overlay sha1 md5 base64 format env code-pages mule custom widget keymap
hashtable-print-readable backquote threads dbusbind inotify
dynamic-setting system-font-setting font-render-setting cairo gtk pgtk
lcms2 multi-tty move-toolbar make-network-process tty-child-frames
native-compile emacs)

Memory information:
((conses 16 348255 236056) (symbols 48 21674 0)
 (strings 32 85000 11286) (string-bytes 1 2720636) (vectors 16 38169)
 (vector-slots 8 1104566 168128) (floats 8 143 137)
 (intervals 56 14651 3188) (buffers 1064 19))