Reparsing on every keypress causing slow editor experience

[spintonp4]

Type: Performance Issue

Open a large C++ project. Edit any C++ file and the parsing icon in the bottom status bar is displayed on every key press. As a consequence typing is really slow in the editor. I've turned off as many editor features as I can find, but still no luck in stopping the constant reparse.

VS Code version: Code 1.90.1 (611f9bf, 2024-06-11T21:02:43.666Z)
OS version: Linux x64 6.8.0-35-generic snap
Modes:

System Info

Item	Value
CPUs	Intel(R) Core(TM) i7-10850H CPU @ 2.70GHz (8 x 0)
GPU Status	2d_canvas: enabled canvas_oop_rasterization: disabled_off direct_rendering_display_compositor: disabled_off_ok gpu_compositing: enabled multiple_raster_threads: enabled_on opengl: enabled_on rasterization: enabled raw_draw: disabled_off_ok skia_graphite: disabled_off video_decode: enabled video_encode: disabled_software vulkan: disabled_off webgl: enabled webgl2: enabled webgpu: disabled_off
Load (avg)	3, 1, 1
Memory (System)	23.42GB (20.38GB free)
Process Argv	--no-sandbox --use-gl=angle --use-angle=swiftshader --crash-reporter-id 534804b0-60c7-44f3-b658-7cd9d8e6fb0d
Screen Reader	no
VM	100%
DESKTOP_SESSION	ubuntu
XDG_CURRENT_DESKTOP	Unity
XDG_SESSION_DESKTOP	ubuntu
XDG_SESSION_TYPE	wayland

Process Info

CPU %	Mem MB	   PID	Process
    0	    96	  4479	code main
    0	     0	  4482	   zygote
    0	     0	  4483	   zygote
    0	   408	  4557	window [1] (F_NatLoop.lzz - head2 (Workspace) - Visual Studio Code)
    0	    72	 38887	window [3] (Issue Reporter)
    0	   192	  4510	   gpu-process
    0	    24	  4524	   utility-network-service
    0	   120	  4575	extensionHost [1]
    0	   360	  5152	     /home/spinton/.vscode/extensions/ms-vscode.cpptools-1.20.5-linux-x64/bin/cpptools
    0	    24	  5237	     /snap/code/161/usr/share/code/code /snap/code/161/usr/share/code/resources/app/extensions/json-language-features/server/dist/node/jsonServerMain --node-ipc --clientProcessId=4575
    0	    48	  4590	shared-process
    0	     0	 39805	     /bin/sh -c /usr/bin/ps -ax -o pid=,ppid=,pcpu=,pmem=,command=
    0	   120	  4591	fileWatcher [1]

Workspace Info

|  Window (F_NatLoop.lzz - head2 (Workspace) - Visual Studio Code)
|    Folder (head2): more than 23774 files
|      File types: C(6883) h(2345) expect(2295) cc(1847) cpp(1725) cxx(531)
|                  lzz(357) cm(335) prj(315) out(305)
|      Conf files: makefile(115) launch.json(1) settings.json(1) tasks.json(1)
|      Launch Configs: lldb(5) python(2) cppdbg;

Extensions (20)

Extension	Author (truncated)	Version
Bookmarks	ale	13.5.0
bpftrace	bpf	0.2.1
xml	Dot	2.5.1
black-formatter	ms-	2024.2.0
debugpy	ms-	2024.6.0
isort	ms-	2023.10.1
python	ms-	2024.8.1
vscode-pylance	ms-	2024.6.1
jupyter-keymap	ms-	1.1.2
remote-ssh	ms-	0.112.0
remote-ssh-edit	ms-	0.86.0
vscode-remote-extensionpack	ms-	0.25.0
cpptools	ms-	1.20.5
cpptools-extension-pack	ms-	1.3.0
remote-explorer	ms-	0.4.3
remote-server	ms-	1.5.2
jinjahtml	sam	0.20.0
graphviz-interactive-preview	tin	0.3.5
vscode-lldb	vad	1.10.0
vscode-proto3	zxh	0.5.5

(1 theme extensions excluded)

A/B Experiments

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pythonmypyd1:30879173
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pythonprt:31056678
dwnewjupyter:31046869
newcmakeconfigv2:31071590
legacy_priority:31077528

[gjsjohnmurray]

Do you still have the problem after updating to 1.90.2?

[Kossak-esky]

I had the same experience. Moving cursor down 1 line took about 1 second! I thought some extension might be the cause, but upgrading to 1.90.2 fixed the issue for me.

[spintonp4]

Yes, I'm on 1.90.2 now and the problem seems to have gone. As I type, the code and gnome-shell processes are taking far less CPU (they were up to about 300% CPU if I held down a key).