Package: emacs;
Reported by: Naofumi Yasufuku <naofumi <at> yasufuku.dev>
Date: Thu, 3 Jun 2021 15:08:02 UTC
Severity: normal
Tags: confirmed, fixed, patch
Merged with 45379, 47494, 47565
Found in version 28.0.50
Fixed in version 28.1
Done: Stefan Kangas <stefan <at> marxist.se>
Bug is archived. No further changes may be made.
View this message in rfc822 format
From: Naofumi Yasufuku <naofumi <at> yasufuku.dev> To: 48812 <at> debbugs.gnu.org Subject: bug#48812: 28.0.50; describe-bindings stucks and gets high CPU load Date: Fri, 4 Jun 2021 00:15:06 +0900
[Message part 1 (text/plain, inline)]
Attached simple patch could fix this. Is there no regression with this change? Regards, —Naofumi
[0001-Fix-describe-bindings-stuck-caused-by-heavy-shadow_l.patch (application/octet-stream, attachment)]
[Message part 3 (text/plain, inline)]
> On Jun 4, 2021, at 0:06, Naofumi Yasufuku <naofumi <at> yasufuku.dev> wrote:
>
> This describe-bindings stuck is caused by millions of shadow_lookup() calls
> in src/keymap.c describe_vector().
>
> ------------------------------------------------------------------------
> $ ./src/emacs
> describe_vector] shadow_lookup loop START: definition=self-insert-command shadowed_by=nil starting_i=128 i=4194175
> describe_vector] shadow_lookup loop END: definition=self-insert-command shadowed_by=nil starting_i=128 i=4194175
> describe_vector] shadow_lookup loop START: definition=self-insert-command shadowed_by=nil starting_i=4194176 i=4194303
> describe_vector] shadow_lookup loop END: definition=self-insert-command shadowed_by=nil starting_i=4194176 i=4194303
> describe_vector] shadow_lookup loop START: definition=digit-argument shadowed_by=nil starting_i=48 i=57
> describe_vector] shadow_lookup loop END: definition=digit-argument shadowed_by=nil starting_i=48 i=57
> $
> ------------------------------------------------------------------------
> diff --git a/src/keymap.c b/src/keymap.c
> index fb8eceaec1..0efa78ce9b 100644
> --- a/src/keymap.c
> +++ b/src/keymap.c
> @@ -3065,6 +3065,11 @@ describe_vector (Lisp_Object vector, Lisp_Object prefix, Lisp_Object args,
> if (CHAR_TABLE_P (vector) && i != starting_i)
> {
> Lisp_Object key = make_nil_vector (1);
> + fprintf (stderr, "%s] shadow_lookup loop START: definition=%s shadowed_by=%s starting_i=%d i=%d\n",
> + __func__,
> + SDATA (SYMBOL_NAME (definition)),
> + SDATA (SYMBOL_NAME (shadowed_by)),
> + starting_i, i);
> for (int j = starting_i + 1; j <= i; j++)
> {
> ASET (key, 0, make_fixnum (j));
> @@ -3072,6 +3077,11 @@ describe_vector (Lisp_Object vector, Lisp_Object prefix, Lisp_Object args,
> if (NILP (Fequal (tem, shadowed_by)))
> i = j - 1;
> }
> + fprintf (stderr, "%s] shadow_lookup loop END: definition=%s shadowed_by=%s starting_i=%d i=%d\n",
> + __func__,
> + SDATA (SYMBOL_NAME (definition)),
> + SDATA (SYMBOL_NAME (shadowed_by)),
> + starting_i, i);
> }
>
> /* If we have a range of more than one character,
> ------------------------------------------------------------------------
>
>
> This shadow_lookup() loop was introduced by the following commit:
>
> ------------------------------------------------------------------------
> commit a6490343366f2b2331a91dcb693effb3a9dd78f5
> Author: Stefan Kangas <stefan <at> marxist.se>
> Date: Fri Nov 13 15:28:29 2020 +0100
>
> Don't show key ranges if shadowed by different commands
>
> * src/keymap.c (describe_vector): Make sure found consecutive keys
> are either not shadowed or, if they are, that they are shadowed by
> the same command. (Bug#9293)
> * test/src/keymap-tests.el
> (help--describe-vector/bug-9293-one-shadowed-in-range): New test.
>
> ------------------------------------------------------------------------
>
>
> <28.0.50-describe-bindings-01.png>
>
> <28.0.50-describe-bindings-02.png>
>
> <27.1-ubuntu-describe-bindings.png>
>
>
> In GNU Emacs 28.0.50 (build 3, aarch64-unknown-linux-gnu, GTK+ Version 3.24.25, cairo version 1.16.0)
> of 2021-06-03 built on phoebe
> Repository revision: 089e0c4c55dcf72f9cf2f6f04b8a52fc7355499c
> Repository branch: master
> Windowing system distributor 'The X.Org Foundation', version 11.0.12101001
> System Description: Ubuntu 21.04
>
> Configured features:
> CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GPM GSETTINGS HARFBUZZ JPEG JSON
> LCMS2 LIBSELINUX LIBSYSTEMD LIBXML2 MODULES NOTIFY INOTIFY PDUMPER PNG
> RSVG SECCOMP SOUND THREADS TIFF TOOLKIT_SCROLL_BARS X11 XDBE XIM XPM
> GTK3 ZLIB
>
> Important settings:
> value of $LANG: en_US.UTF-8
> value of $XMODIFIERS: @im=ibus
> locale-coding-system: utf-8-unix
>
> Major mode: C/*l
>
> Minor modes in effect:
> bug-reference-prog-mode: t
> tooltip-mode: t
> global-eldoc-mode: t
> electric-indent-mode: t
> mouse-wheel-mode: t
> tool-bar-mode: t
> menu-bar-mode: t
> file-name-shadow-mode: t
> global-font-lock-mode: t
> font-lock-mode: t
> blink-cursor-mode: t
> auto-composition-mode: t
> auto-encryption-mode: t
> auto-compression-mode: t
> line-number-mode: t
> transient-mark-mode: t
> abbrev-mode: t
>
> Load-path shadows:
> None found.
>
> Features:
> (shadow sort mail-extr emacsbug message rmc puny rfc822 mml mml-sec epa
> derived epg epg-config gnus-util rmail rmail-loaddefs auth-source cl-seq
> eieio eieio-core cl-macs eieio-loaddefs password-cache json map
> text-property-search mm-decode mm-bodies mm-encode mail-parse rfc2231
> mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums
> mm-util mail-prsvr mail-utils vc-git diff-mode easy-mmode vc
> vc-dispatcher bug-reference cc-mode cc-fonts cc-guess cc-menus cc-cmds
> cc-styles cc-align cc-engine cc-vars cc-defs misearch multi-isearch
> dired-aux dired dired-loaddefs time-date subr-x cl-extra seq byte-opt gv
> bytecomp byte-compile cconv kmacro two-column help-mode cl-loaddefs
> cl-lib iso-transl tooltip eldoc electric uniquify ediff-hook vc-hooks
> lisp-float-type mwheel term/x-win x-win term/common-win x-dnd tool-bar
> dnd fontset image regexp-opt fringe tabulated-list replace newcomment
> text-mode elisp-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 cl-generic
> 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 charscript charprop
> case-table epa-hook jka-cmpr-hook help simple abbrev obarray
> cl-preloaded nadvice button loaddefs faces cus-face macroexp files
> window text-properties overlay sha1 md5 base64 format env code-pages
> mule custom widget hashtable-print-readable backquote threads dbusbind
> inotify lcms2 dynamic-setting system-font-setting font-render-setting
> cairo move-toolbar gtk x-toolkit x multi-tty make-network-process emacs)
>
> Memory information:
> ((conses 16 118009 7881)
> (symbols 48 9308 1)
> (strings 32 27924 2053)
> (string-bytes 1 1038142)
> (vectors 16 18491)
> (vector-slots 8 227657 9510)
> (floats 8 31 163)
> (intervals 56 10630 0)
> (buffers 992 14))
>
>
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