--- Begin Message ---
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Subject: |
28.0.50; Emacs freezes with big C functions |
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Date: |
Tue, 15 Dec 2020 09:29:12 +0530 |
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User-agent: |
mu4e 1.5.7; emacs 28.0.50 |
Scrolling through large functions freezes Emacs. For example,
the function proto_register_rrc(void) extracted from Wireshark
shows the issue.
https://gitlab.com/wireshark/wireshark/-/raw/master/epan/dissectors/packet-rrc.c
Profile report with emacs -Q:
https://gist.github.com/ravine-var/9136ed2608a08f65111bdc2fc531ccf5
In GNU Emacs 28.0.50 (build 1, x86_64-pc-linux-gnu, cairo version 1.17.4)
of 2020-12-15 built on ryzen-mach
Repository revision: fd4297b25a61b33340ef312355748512e702bc2c
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12010000
System Description: Arch Linux
Configured using:
'configure --prefix=/usr/local --without-rsvg --with-x-toolkit=no
--without-lcms2 --without-libsystemd --without-dbus --without-gsettings
--without-selinux --with-sound=no --enable-link-time-optimization
'CFLAGS=-O2 -march=native''
Configured features:
XPM JPEG TIFF GIF PNG CAIRO NOTIFY INOTIFY ACL GNUTLS LIBXML2 FREETYPE
HARFBUZZ ZLIB OLDXMENU X11 XDBE XIM MODULES THREADS PDUMPER
Important settings:
value of $LANG: en_IN.UTF-8
locale-coding-system: utf-8-unix
Major mode: Dired by name
Minor modes in effect:
save-place-mode: t
savehist-mode: t
dired-omit-mode: t
mouse-wheel-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
buffer-read-only: t
column-number-mode: 1
line-number-mode: t
transient-mark-mode: t
Load-path shadows:
~/packages/xcscope/xcscope hides /usr/share/emacs/site-lisp/xcscope
~/packages/dictionary-el/dictionary hides
/usr/local/share/emacs/28.0.50/lisp/net/dictionary
Features:
(shadow face-remap emacsbug dired-aux cl-extra help-mode edmacro kmacro
emms-browser sort emms-playlist-sort emms-last-played emms-cache
emms-volume emms-volume-mixerctl emms-volume-pulse emms-volume-amixer
emms-info-libtag emms-info emms-later-do emms-player-simple
emms-playlist-mode emms-source-playlist emms-source-file locate emms
emms-compat saveplace savehist visual-fill-column mu4e-contrib eshell
esh-cmd esh-ext esh-opt esh-proc esh-io esh-arg esh-module esh-groups
esh-util bookmark pp mu4e mu4e-org mu4e-main mu4e-view thingatpt
mu4e-headers mu4e-compose mu4e-context mu4e-draft mu4e-actions ido
rfc2368 smtpmail sendmail mu4e-mark mu4e-proc mu4e-utils doc-view
jka-compr image-mode exif mu4e-lists mu4e-message shr kinsoku svg xml
dom browse-url url url-proxy url-privacy url-expand url-methods
url-history url-cookie url-domsuf url-util url-parse url-vars mailcap
flow-fill org ob ob-tangle ob-ref ob-lob ob-table ob-exp org-macro
org-footnote org-src ob-comint org-pcomplete pcomplete comint ansi-color
org-list org-faces org-entities noutline outline easy-mmode org-version
ob-emacs-lisp ob-core ob-eval org-table ol org-keys org-compat advice
org-macs org-loaddefs format-spec find-func cal-menu calendar
cal-loaddefs mule-util hl-line mu4e-vars 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 time-date subr-x seq
byte-opt gv bytecomp byte-compile cconv mm-decode mm-bodies mm-encode
mail-parse rfc2231 rfc2047 rfc2045 mm-util ietf-drums mail-prsvr
mailabbrev mail-utils gmm-utils mailheader cl-loaddefs cl-lib mu4e-meta
dictionary link connection cycbuf dired-x dired dired-loaddefs xcscope
ring easymenu 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 timer select scroll-bar mouse
jit-lock font-lock syntax facemenu 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 inotify dynamic-setting font-render-setting cairo x
multi-tty make-network-process emacs)
Memory information:
((conses 16 145029 10616)
(symbols 48 16107 1)
(strings 32 54243 2983)
(string-bytes 1 1799965)
(vectors 16 28914)
(vector-slots 8 327029 18380)
(floats 8 151 158)
(intervals 56 538 134)
(buffers 984 12))
--- End Message ---
--- Begin Message ---
|
Subject: |
Re: bug#45248: 28.0.50; Emacs freezes with big C functions |
|
Date: |
Thu, 24 Dec 2020 11:50:14 +0000 |
Hello, Ravine.
On Wed, Dec 23, 2020 at 08:48:26 +0530, Ravine Var wrote:
> Alan Mackenzie <acm@muc.de> writes:
> > Sorry it's taken a little while to reply. I've been preoccupied with
> > another bug in the meantime.
> No problem.
> > By "scrolling becomes slower", do you mean (1) that the time for an
> > isolated single full screen scroll becomes longer, the further you are
> > through that struct? Or do you mean (2) that on auto-repeat of the C-v
> > or PageDown key, the scrolling becomes slower?
> The second behavior. Opening the file and scrolling from the
> the beginning with C-v becomes progressively slower.
> > If you mean (2), from emacs -Q without enabling
> > fast-but-imprecise-scrolling, then you are just seeing the normal
> > expected, but unfortunate behaviour of Emacs: Emacs will not redisplay a
> > screen as long as there is keyboard input unprocessed, but Emacs is
> > spending its time fontifying the intermediate screens (which are not
> > about to be displayed) as part of processing that input. 30 characters
> > per second is faster than CC Mode can paint a single screen.
> Ok.
> > For problem (2) I recommend, again, enabling
> > fast-but-imprecise-scrolling.
> Without the patch in message 11, scrolling is bad
> even when fast-but-imprecise-scrolling is enabled.
> With the patch, things are much better and there
> is no lockup, once fast-but-imprecise-scrolling is enabled.
> I think this is enough for this bug - thanks for
> looking into this issue.
Thanks! I've found some infinite loops, which I've also corrected. And
I've committed the patch to the savannah master branch.
So, I'm closing the bug with this post. Thanks for all the testing and
profiling in sorting out this bug.
--
Alan Mackenzie (Nuremberg, Germany).
--- End Message ---