Hi,
I can reproduce systematically this freeze dealing with a 10000lines
Python file :
wget https://raw.githubusercontent.com/hugsy/gef/refs/heads/main/gef.py
emacs -Q gef.py
PageDown several times or scrolling with the mouse
Emacs freezes, Ctrl-g not working, CPU 100%
It works also by searching : Ctrl-s show RET
then Ctrl-s several times
With a minimal .emacs :
(set debug-on-error t)
(set debug-on-quit t)
and before scrolling
M-x profiler-start RET
then in an external terminal
pkill -SIGUSR2 emacs
I get the backtrace :
Debugger entered--entering a function:
* #f(compiled-function () #<bytecode -0x179dcd1db31182ae>)()
syntax-ppss()
python-syntax-context-type()
python-nav-forward-block(-1)
python-nav-backward-block()
python-nav-beginning-of-block()
python-nav-end-of-block()
python-info-statement-ends-block-p()
python-info-end-of-block-p()
python-nav--forward-sexp(1 nil nil)
python-nav-forward-sexp(1)
forward-sexp(1)
up-list(1)
python--font-lock-f-strings(30419)
font-lock-fontify-keywords-region(28914 30419 nil)
font-lock-default-fontify-region(28914 30414 nil)
font-lock-fontify-region(28914 30414)
#f(compiled-function (fun) #<bytecode -0x8a96d65e1315e71>)(font-lock-fontify-region)
run-hook-wrapped(#f(compiled-function (fun) #<bytecode -0x8a96d65e1315e71>) font-lock-fontify-region)
jit-lock--run-functions(28914 30414)
jit-lock-fontify-now(28914 30414)
jit-lock-function(28914)
and can look at profiler report
M-x profiler-stop
M-x profiler-report
showing time spent in syntax-ppss
17770 88% - jit-lock-function
17770 88% - jit-lock-fontify-now
17770 88% - jit-lock--run-functions
17770 88% - run-hook-wrapped
17770 88% - #<byte-code-function FA0>
17770 88% - font-lock-fontify-region
17770 88% - font-lock-default-fontify-region
17690 87% - font-lock-fontify-keywords-region
17678 87% - python--font-lock-f-strings
17674 87% - up-list
17674 87% - forward-sexp
17674 87% - python-nav-forward-sexp
17674 87% - python-nav--forward-sexp
9253 45% - python-info-end-of-block-p
9245 45% - python-info-statement-ends-block-p
9221 45% - python-nav-end-of-block
8609 42% - python-nav-beginning-of-block
8557 42% - python-nav-backward-block
8557 42% - python-nav-forward-block
8005 39% - python-syntax-context-type
7997 39% - syntax-ppss
7097 35% parse-partial-sexp
753 3% + #<byte-code-function A23>
376 1% + python-nav-beginning-of-statement
132 0% re-search-backward
24 0% looking-at
28 0% current-indentation
8 0% + python-nav-beginning-of-statement
4 0% python-info-current-line-empty-p
4 0% + python-info-current-line-comment-p
604 2% + python-nav-end-of-statement
4 0% + python-info-current-line-comment-p
4 0% current-indentation
24 0% + python-nav-end-of-statement
8 0% + python-info-end-of-statement-p
8178 40% - python-info-statement-ends-block-p
8150 40% - python-nav-end-of-block
7754 38% - python-nav-beginning-of-block
7738 38% - python-nav-backward-block
7734 38% - python-nav-forward-block
7178 35% - python-syntax-context-type
7174 35% - syntax-ppss
6978 34% parse-partial-sexp
8 0% make-closure
8 0% #<byte-code-function B1E>
4 0% syntax-table
4 0% syntax-ppss--update-stats
412 2% + python-nav-beginning-of-statement
92 0% re-search-backward
44 0% looking-at
12 0% current-indentation
4 0% looking-at
380 1% + python-nav-end-of-statement
16 0% + python-util-forward-comment
28 0% + python-nav-end-of-statement
151 0% + python-nav-end-of-block
28 0% + python-info-beginning-of-block-p
24 0% + python-info-end-of-statement-p
20 0% + python-info-beginning-of-statement-p
8 0% + python-syntax-context-type
8 0% + python-info-statement-starts-block-p
4 0% + syntax-ppss
8 0% + #<byte-code-function 7E0>
4 0% + #<byte-code-function 740>
80 0% + font-lock-fontify-syntactically-region
2279 11% Automatic GC
73 0% + redisplay_internal (C function)
40 0% + command-execute
8 0% + ...
4 0% + mouse--click-1-maybe-follows-link
other people talking about python/profiling/syntax-ppss :
https://www.reddit.com/r/emacs/comments/z0oye9/emacs_freezes_when_opening_a_python_file/
https://www.reddit.com/r/emacs/comments/9h7onq/large_python_files_hanging_with_an_unmatched_quote/
Please tell me how I can help ?
Please tell me if there is a workaround without losing python syntax color ?
Thanks
Rehan
In GNU Emacs 31.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version
3.24.43, cairo version 1.18.2) of 2024-12-08 built on cndl
Repository revision: b953bcb17047998c9e41cede7c5e5ffec22209b2
Repository branch: master
System Description: Debian GNU/Linux trixie/sid
Configured using:
'configure --prefix=/home/jean/local/emacs --with-pgtk'
Configured features:
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LIBXML2 MODULES NOTIFY INOTIFY PDUMPER PGTK PNG SECCOMP SOUND THREADS
TIFF TOOLKIT_SCROLL_BARS WEBP XIM GTK3 ZLIB
Important settings:
value of $LANG: en_US.UTF-8
value of $XMODIFIERS: @im=ibus
locale-coding-system: utf-8-unix
Major mode: Python
Minor modes in effect:
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show-paren-mode: t
electric-indent-mode: t
mouse-wheel-mode: t
tool-bar-mode: t
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file-name-shadow-mode: t
global-font-lock-mode: t
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Load-path shadows:
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Features:
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page tab-bar menu-bar rfn-eshadow isearch easymenu timer select
scroll-bar mouse jit-lock font-lock syntax font-core term/tty-colors
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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 multi-tty move-toolbar
make-network-process emacs)
Memory information:
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