Doom-emacs: Backspace Latency (doom/delete-backward-char)

[ghost]

Observed behavior

Doom experiences increased input latency when entering the backspace key. Holding down the key causes the application to pause as it processes the function. This behavior is most visibly seen when editing .tex files.

Running the profiler I noticed this function using memory/cpu expensively:

    - doom/delete-backward-char                       298,266,708  94%

Expected behavior

There should be no input lag when entering the backspace key.

Steps to reproduce

1. Open a .tex file
2. Hold down the backspace key
3. Wait before the application responds

System information

OS: Arch Linux
CPU: Intel i7-7500U 3.500GHz
MEMORY: 16 gb

```
Replace this line with the output of one of these commands:

• OS: gnu/linux (x86_64-pc-linux-gnu)
• Emacs: 25.3.1 (Feb 08, 2018)
• Doom: 2.0.9 (develop https://github.com/hlissner/doom-emacs/commit/e6aad90db5f4b606fdc0a079fd00ada6c2bfca27)
• Graphic display: nil (daemon: nil)
• System features: XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GPM DBUS GCONF GSETTINGS NOTIFY ACL GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB TOOLKIT_SCROLL_BARS GTK3 X11 MODULES
• Details:
  ```elisp
  modules: (:config :feature (eval nil) (evil nil) (file-templates nil) (lookup (+devdocs +docsets)) (snippets nil) (spellcheck nil) (syntax-checker nil) (version-control nil) (workspaces nil) :completion (ivy nil) :ui (doom-modeline nil) (hl-todo nil) (nav-flash nil) (evil-goggles nil) (vi-tilde-fringe nil) (window-select nil) :tools (electric-indent nil) (imenu nil) (make nil) (pdf nil) (term nil) :lang (emacs-lisp nil) (latex nil) (markdown nil) (org (+attach +babel +capture +export +present)) (php nil) (python nil) (sh nil) (web nil) :app :config :private)
  packages: (ace-link ace-window adaptive-wrap all-the-icons anaconda-mode async auctex auto-compile auto-yasnippet avy (centered-window :recipe (centered-window :fetcher github :repo anler/centered-window-mode)) cmake-mode command-log-mode company company-anaconda company-auctex company-dict (company-glsl :recipe (company-glsl :fetcher github :repo Kaali/company-glsl)) company-irony company-irony-c-headers company-php company-quickhelp company-shell company-statistics company-web counsel counsel-css counsel-dash counsel-projectile cuda-mode demangle-mode devdocs dired-k disaster doom-themes dumb-jump editorconfig (emacs-snippets :recipe (emacs-snippets :fetcher github :repo hlissner/emacs-snippets :files (*))) emmet-mode evil evil-anzu evil-args evil-commentary evil-easymotion evil-embrace evil-escape evil-exchange evil-goggles evil-indent-plus evil-matchit evil-mc evil-multiedit evil-numbers evil-org evil-snipe evil-surround evil-textobj-anyblock evil-vimish-fold evil-visualstar (exec-path-from-shell :ignore t) expand-region flycheck flycheck-cask flycheck-irony flycheck-popup-tip flycheck-pos-tip flyspell flyspell-correct flyspell-correct-ivy fringe-helper git-gutter-fringe git-link git-timemachine gitconfig-mode gitignore-mode glsl-mode haml-mode helpful hide-mode-line highlight-indentation highlight-numbers highlight-quoted hl-todo htmlize hydra imenu-anywhere imenu-list irony irony-eldoc ivy ivy-bibtex ivy-hydra ivy-rich ivy-rtags ivy-xref langtool less-css-mode macrostep magit makefile-executor markdown-mode markdown-toc mixed-pitch modern-cpp-font-lock multi-term nav-flash nlinum nlinum-hl nlinum-relative nose ob-mongo ob-sql-mode ob-translate opencl-mode (org-bullets :recipe (org-bullets :fetcher github :repo Kaligule/org-bullets)) org-download org-plus-contrib org-tree-slide (osx-clipboard :ignore t) overseer ox-pandoc ox-reveal pcre2el pdf-tools persistent-soft persp-mode php-boris (php-extras :recipe (php-extras :fetcher github :repo arnested/php-extras)) php-mode php-refactor-mode phpunit pip-requirements projectile pug-mode quelpa quickrun rainbow-delimiters rainbow-mode rtags sass-mode shackle shrink-path slime smart-forward smartparens smex solaire-mode stylus-mode swiper synosaurus toc-org undo-tree use-package vi-tilde-fringe visual-fill-column web-beautify web-mode wgrep which-key wordnut yasnippet)
  elc dirs: (modules/tools/rotate-text/)
  exec-path: (/usr/local/sbin /usr/local/bin /usr/bin /usr/bin/site_perl /usr/bin/vendor_perl /usr/bin/core_perl /usr/lib/emacs/25.3/x86_64-pc-linux-gnu)
  

[hlissner]

Yikes, it appears that smartparens sets a _lot_ of rules for (la)?tex-mode, which is what makes the underlying calls to sp-get-thing so expensive.

I'll try two things to fix this: try to cache/optimize doom/delete-backward-char's calls to sp-get-thing, and to cut down on all those extra smartparens rules.

In the meantime, try adding this to your private config:

(after! tex-mode
  (map-delete sp-pairs 'LaTeX-mode)
  (map-delete sp-pairs 'latex-mode)
  (map-delete sp-pairs 'tex-mode)
  (map-delete sp-pairs 'plain-tex-mode))

And let me know if the result is acceptable.

[ghost]

Thanks for the quick response. I implemented your suggestion and the keys are far more usable now.

Also, just wanted to say that I've gone through almost every major text editor / config (spacemacs, vim, sublime, atom, etc...) and yours is by far the best one. Keep on rocking man! I don't know much elisp at the moment, but if you need any help with the documentation to make it more beginner friendly or need some designs, I'd be willing to contribute.

[hlissner]

Alright, I've removed the smartparens rules from lang/latex in develop. A more thorough solution is warranted, but this should do for now. I'll keep this open until it gets merged into master.

[skosch]

I'm experiencing the same issue with large files in web-mode (or derivative modes). Deleting with x is fast as expected, but deletion via backspace is halting and stuttering.

Do you think this might be related to smartparens as well? I can open a new issue if you don't want to re-open this one.

[hlissner]

@skosch Are you still experiencing this issue? It could very well be smartparens, but I've also made a number of changes to it and its integration into web-mode.

[hlissner]

I'll assume this is resolved. Feel free to follow up otherwise.

[zephirefaith]

Hi. I am seeing this behavior replicate in the org-mode. Here's the output from my doom-profiler:

[hlissner]

@zephirefaith please provide M-x doom/info

[zephirefaith]

Sorry about that. Here you go -

emacs   version    26.2
        features   XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GPM DBUS GSETTINGS GLIB NOTIFY LIBSELINUX GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB TOOLKIT_SCROLL_BARS GTK3 X11 XDBE XIM MODULES THREADS XWIDGETS LIBSYSTEMD LCMS2
        build      Apr 12, 2019
        buildopts  (--build=x86_64-linux-gnu --prefix=/usr '--includedir=${prefix}/include' '--mandir=${prefix}/share/man' '--infodir=${prefix}/share/info' --sysconfdir=/etc --localstatedir=/var --disable-silent-rules '--libdir=${prefix}/lib/x86_64-linux-gnu' '--libexecdir=${prefix}/lib/x86_64-linux-gnu' --disable-maintainer-mode --disable-dependency-tracking --prefix=/usr --sharedstatedir=/var/lib --program-suffix=26 --with-modules --with-file-notification=inotify --with-mailutils --with-x=yes --with-x-toolkit=gtk3 --with-xwidgets --with-lcms2 'CFLAGS=-g -O2 -fstack-protector-strong -Wformat -Werror=format-security' 'CPPFLAGS=-Wdate-time -D_FORTIFY_SOURCE=2' 'LDFLAGS=-Wl,-Bsymbolic-functions -Wl,-z,relro')
doom    version    2.0.9
        build      HEAD -> develop a217b01 2019-09-12 17:26:12 -0400
system  type       gnu/linux
        config     x86_64-pc-linux-gnu
        shell      /usr/bin/zsh
        uname      Linux 4.15.0-62-generic #69~16.04.1-Ubuntu SMP Fri Sep 6 02:43:35 UTC 2019 x86_64
        path       (~/base_py27/bin ~/bin ~/.emacs.d/bin /usr/local/cuda-9.1/bin ~/base_py27/bin ~/bin ~/.emacs.d/bin /usr/local/cuda-9.1/bin /home/linuxbrew/.linuxbrew/bin /home/linuxbrew/.linuxbrew/sbin ~/bin ~/.local/bin /usr/local/sbin /usr/local/bin /usr/sbin /usr/bin /sbin /bin /usr/games /usr/local/games /snap/bin /opt/cogrob/bin /usr/local/cuda/bin /home/zephirefaith/.gem/bin ~/.fzf/bin ~/.gem/bin /home/zephirefaith/.gem/bin ~/.gem/bin /usr/lib/x86_64-linux-gnu/emacs/26.2/x86_64-linux-gnu/)
config  envfile    envvar-file
        elc-files  0
        modules    (:completion company helm :ui doom doom-dashboard doom-quit fill-column hl-todo indent-guides modeline nav-flash ophints (popup +all +defaults) pretty-code treemacs vc-gutter vi-tilde-fringe window-select workspaces :editor evil file-templates fold (format +onsave) multiple-cursors rotate-text snippets word-wrap :emacs dired electric vc :tools editorconfig ein eval flycheck (lookup +docsets) magit pdf :lang cc data julia latex markdown (org +dragndrop +ipython +pandoc +present) python sh :app calendar (write +wordnut +langtool) :config default)
        packages   (n/a)
        elpa-packages (n/a)

[alexDarcy]

Hi, I'm also experiencing the same issue as zephiraith. Below is the output of the profilier (CPU) and doom/info. Thanks !

emacs   version    26.3
        features   XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GPM DBUS GSETTINGS GLIB NOTIFY ACL GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB TOOLKIT_SCROLL_BARS GTK3 X11 XDBE XIM MODULES THREADS LIBSYSTEMD LCMS2
        build      Aug 29, 2019
        buildopts  (--prefix=/usr --sysconfdir=/etc --libexecdir=/usr/lib --localstatedir=/var --with-x-toolkit=gtk3 --with-xft --with-modules 'CFLAGS=-march=x86-64 -mtune=generic -O2 -pipe -fno-plt' CPPFLAGS=-D_FORTIFY_SOURCE=2 LDFLAGS=-Wl,-O1,--sort-common,--as-needed,-z,relro,-z,now)
        windowsys  x
        daemonp    daemon
doom    version    2.0.9
        build      HEAD -> develop 5f2e708cd 2019-12-12 03:48:25 -0500
system  type       gnu/linux
        config     x86_64-pc-linux-gnu
        shell      /bin/bash
        uname      Linux 5.4.2-arch1-1 #1 SMP PREEMPT Thu, 05 Dec 2019 12:29:40 +0000 x86_64
        path       (/usr/local/sbin/ /usr/local/bin/ /usr/bin/ /usr/lib/jvm/default/bin/ /usr/bin/site_perl/ /usr/bin/vendor_perl/ /usr/bin/core_perl/ ~/.local/bin/ ~/.emacs.d/bin/ ~/.local/bin/ ~/.emacs.d/bin/ /usr/lib/emacs/26.3/x86_64-pc-linux-gnu/)
config  envfile    envvar-file
        elc-files  0
        modules    (:completion company ivy :ui doom doom-dashboard doom-quit hl-todo modeline nav-flash ophints (popup +all +defaults) treemacs vc-gutter vi-tilde-fringe window-select workspaces :editor (evil +everywhere) file-templates fold multiple-cursors rotate-text snippets :emacs dired electric vc :term eshell :tools eval flycheck (lookup +docsets) lsp magit pdf :lang common-lisp data emacs-lisp (haskell +lsp) latex ledger markdown (org +dragndrop +ipython +pandoc +present) sh :email notmuch :app calendar :config (default +bindings +smartparens))
        packages   (n/a)
        elpa       (n/a)

[hlissner]

@alexDarcy What major mode(s) are you seeing this in?

[alexDarcy]

@hlissner thanks for the quick answer. I'm seeing it in org-mode, in a file with roughly 1 000 lines. Disabling smartparens is good enough for me at the moment.

[mvanaltvorst]

I'm facing this issue in org-mode too. Disabling smartparens seems to work, though this solution is not ideal. doom/info below.

emacs   version    26.3
        features   XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GPM DBUS GSETTINGS GLIB NOTIFY ACL GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB TOOLKIT_SCROLL_BARS GTK3 X11 XDBE XIM MODULES THREADS LIBSYSTEMD LCMS2
        build      aug 29, 2019
        buildopts  (--prefix=/usr --sysconfdir=/etc --libexecdir=/usr/lib --localstatedir=/var --with-x-toolkit=gtk3 --with-xft --with-modules 'CFLAGS=-march=x86-64 -mtune=generic -O2 -pipe -fno-plt' CPPFLAGS=-D_FORTIFY_SOURCE=2 LDFLAGS=-Wl,-O1,--sort-common,--as-needed,-z,relro,-z,now)
        windowsys  x
        daemonp    server-running
doom    version    2.0.9
        build      HEAD -> develop, origin/develop, origin/HEAD 6f273ffc2 2020-01-13 01:46:43 -0500
        dir        ~/dotfiles/.doom.d/
system  type       gnu/linux
        config     x86_64-pc-linux-gnu
        shell      /usr/bin/zsh
        uname      Linux 5.4.12-1-MANJARO #1 SMP PREEMPT Wed Jan 15 08:05:08 UTC 2020 x86_64
        path       (~/.local/bin/ ~/.local/bin/ /usr/local/bin/ /usr/bin/ /bin/ /usr/local/sbin/ /usr/bin/site_perl/ /usr/bin/vendor_perl/ /usr/bin/core_perl/ /var/lib/snapd/snap/bin/ /usr/lib/emacs/26.3/x86_64-pc-linux-gnu/)
config  envfile    envvar-file
        elc-files  152
        modules    (:completion company ivy :ui doom doom-dashboard doom-quit hl-todo modeline nav-flash ophints (popup +all +defaults) vc-gutter vi-tilde-fringe window-select workspaces :editor (evil +everywhere) file-templates fold multiple-cursors rotate-text snippets :emacs dired electric ibuffer vc :checkers syntax :tools (eval +overlay) (lookup +docsets) magit pdf :lang data emacs-lisp go (haskell +dante) javascript latex markdown (org +dragndrop +pandoc +pomodoro +present) python sh web :app irc :config (default +bindings +smartparens))
        packages   (erc erc-hl-nicks erc-image)
        elpa       (noflet)

[hperrey]

I have the same issue in org-mode as well. In fact, it is most noticeable when using backspace but I also experience a clear lag when simply typing text in an org buffer (in this case, the buffer is shorter than 1000 lines). Disabling smartparens-mode works around this for me too. System info below.

emacs   version    26.3
        features   NOTIFY ACL GNUTLS LIBXML2 ZLIB TOOLKIT_SCROLL_BARS NS MODULES THREADS
        build      Sep 02, 2019
        buildopts  (--with-ns '--enable-locallisppath=/Library/Application Support/Emacs/${version}/site-lisp:/Library/Application Support/Emacs/site-lisp' --with-modules)
        windowsys  ns
        daemonp    server-running
doom    version    2.0.9
        build      HEAD -> develop b5a279311 2020-01-07 00:14:46 -0500
        dir        ~/.emacs.conf/.doom.d/
system  type       darwin
        config     x86_64-apple-darwin14.5.0
        shell      /bin/bash
        uname      Darwin 17.7.0 Darwin Kernel Version 17.7.0: Sun Dec  1 19:19:56 PST 2019; root:xnu-4570.71.63~1/RELEASE_X86_64 x86_64
        path       (~/anaconda3/bin/ /usr/local/sbin/ ~/local/openscenegraph-3.4.0/bin/ ~/local/geant4_10.00.p03/bin/ /usr/local/root/5.34.36/bin/ ~/bin/ /usr/local/bin/ /usr/bin/ /bin/ /usr/sbin/ /sbin/ /Library/TeX/texbin/ /usr/local/MacGPG2/bin/ /opt/X11/bin/ /usr/local/git/bin/ /Applications/Emacs.app/Contents/MacOS/bin-x86_64-10_10/ /Applications/Emacs.app/Contents/MacOS/libexec-x86_64-10_10/ /Applications/Emacs.app/Contents/MacOS/libexec/)
config  envfile    envvar-file
        elc-files  0
        modules    (:completion company ivy :ui doom doom-dashboard doom-quit hl-todo modeline nav-flash ophints (popup +all +defaults) vc-gutter vi-tilde-fringe window-select workspaces :editor file-templates fold multiple-cursors rotate-text snippets :emacs dired electric ibuffer vc :term eshell term :tools debugger (eval +overlay) flycheck flyspell (lookup +docsets) magit pdf :lang cc data emacs-lisp latex markdown (org +dragndrop +jupyter +pandoc +pomodoro +present) plantuml python sh web :config (default +bindings +smartparens))
        packages   (org-ql ox-reveal org-kanban org-pdfview org-sidebar synosaurus dictcc mastodon org-protocol)
        elpa       (n/a)

[RBckmnn]

I'm also experiencing this whn backspacing within an org-mode file of moderate size (~ 1k lines). Turning off smartparens helps.

emacs   version    26.3
        features   XPM JPEG TIFF GIF PNG RSVG SOUND GPM DBUS GLIB NOTIFY ACL GNUTLS LIBXML2 FREETYPE XFT ZLIB GTK3 X11 XDBE XIM MODULES THREADS XWIDGETS LCMS2
        build      Jan 03, 2020
        buildopts  (--prefix=/usr --build=x86_64-pc-linux-gnu --host=x86_64-pc-linux-gnu --mandir=/usr/share/man --infodir=/usr/share/info --datadir=/usr/share --sysconfdir=/etc --localstatedir=/var/lib --disable-silent-rules --docdir=/usr/share/doc/emacs-26.3-r1 --htmldir=/usr/share/doc/emacs-26.3-r1/html --libdir=/usr/lib64 --program-suffix=-emacs-26 --includedir=/usr/include/emacs-26 --infodir=/usr/share/info/emacs-26 --localstatedir=/var --enable-locallisppath=/etc/emacs:/usr/share/emacs/site-lisp --without-compress-install --without-hesiod --without-pop --with-file-notification=inotify --enable-acl --with-dbus --with-modules --without-gameuser --with-gpm --without-kerberos --without-kerberos5 --with-lcms2 --with-xml2 --without-mailutils --without-selinux --with-gnutls --without-libsystemd --with-threads --without-wide-int --with-zlib --with-sound=alsa --with-x --without-ns --without-gconf --without-gsettings --without-toolkit-scroll-bars --with-gif --with-jpeg --with-png --with-rsvg --with-tiff --with-xpm --without-imagemagick --with-xft --without-cairo --without-libotf --without-m17n-flt --with-x-toolkit=gtk3 --with-xwidgets 'CFLAGS=-march=native -O2 -pipe' CPPFLAGS= 'LDFLAGS=-Wl,-O1 -Wl,--as-needed')
        windowsys  x
        daemonp    server-running
doom    version    2.0.9
        build      HEAD -> develop, upstream/develop 58a68adb5 2020-03-04 23:02:15 -0500
        dir        ~/Workspace/dotfiles/.doom.d/
system  type       gnu/linux
        config     x86_64-pc-linux-gnu
        shell      /bin/bash
        uname      Linux 4.19.97-gentoo #1 SMP Thu Feb 27 00:57:51 CET 2020 x86_64
        path       (/usr/lib/llvm/9/bin /usr/local/sbin /usr/local/bin /usr/sbin /usr/bin /sbin /bin /opt/bin ~/.emacs.d/bin ~/.local/bin /usr/libexec/emacs/26.3/x86_64-pc-linux-gnu)
config  envfile    nil
        elc-files  0
        modules    (:completion company helm :ui doom doom-dashboard hl-todo modeline nav-flash ophints (popup +all +defaults) vc-gutter vi-tilde-fringe window-select workspaces :editor (evil +everywhere) file-templates fold (format +onsave) multiple-cursors rotate-text snippets :emacs (dired +icons) electric ibuffer vc :term vterm :checkers syntax :tools (eval +overlay) (lookup +docsets) lsp magit :lang data emacs-lisp (javascript +lsp) latex markdown (org +dragndrop +present) (python +lsp) (sh +lsp) web :email mu4e :config literate (default +bindings +smartparens))
        packages   ((f) (org-drill) (org-super-agenda) (org-chef) (posframe))
        unpin      (n/a)
        elpa       (n/a)