Scrolling causes significant performance drops

[ok-nick]

Issue Type: Performance Issue

Earlier today I've been having a huge performance drop when scrolling in the editor tab, extension tab, anywhere that scrolls. Whether smooth scroll is toggled or all extensions are disabled, VSCode drops all the way to ~20fps. I've tried reinstalling and restarting to no avail.
I'd be glad to provide profiling logs if needed although I've noticed something specifically pop up in red a bunch of times which may seem alarming?

VS Code version: Code 1.56.0 (cfa2e21, 2021-05-04T22:09:06.405Z)
OS version: Windows_NT x64 10.0.19042

System Info

Item	Value
CPUs	Intel(R) Core(TM) i7-10875H CPU @ 2.30GHz (16 x 2304)
GPU Status	2d_canvas: enabled gpu_compositing: enabled multiple_raster_threads: enabled_on oop_rasterization: enabled opengl: enabled_on rasterization: enabled skia_renderer: enabled_on video_decode: enabled vulkan: disabled_off webgl: enabled webgl2: enabled
Load (avg)	undefined
Memory (System)	15.90GB (8.47GB free)
Process Argv	--crash-reporter-id e643c37a-8eb9-4486-a629-28107525d35f
Screen Reader	no
VM	0%

Process Info

CPU %	Mem MB	   PID	Process
    0	   118	 17004	code main
    4	   161	  4692	   gpu-process
    0	    24	  5720	   crashpad-handler
    0	    39	  6728	   utility
    1	    95	  7400	   shared-process
    0	    60	 20940	     ptyHost
    0	    81	 12728	   utility
    0	   180	 18948	   window (● Untitled-1 - Visual Studio Code)
    0	   233	 12212	     extensionHost
    0	    42	 19564	       c:\Users\nicky\.vscode\extensions\nightrains.robloxlsp-0.15.8\server\bin\Windows\lua-language-server.exe -E -e DEVELOP=undefined;DBGPORT=undefined;DBGWAIT=undefined c:\Users\nicky\.vscode\extensions\nightrains.robloxlsp-0.15.8\server\main.lua
    0	    11	 22928	         console-window-host (Windows internal process)
    0	    93	 23408	       electron_node server.js 
    0	    84	 23320	   window (Issue Reporter)

Workspace Info

;

Extensions (25)

Extension	Author (truncated)	Version
project-manager	ale	12.1.0
better-toml	bun	0.3.2
bracket-pair-colorizer-2	Coe	0.2.0
vscode-markdownlint	Dav	0.40.4
vscode-eslint	dba	2.1.20
gitlens	eam	11.4.1
EditorConfig	Edi	0.16.4
vscode-great-icons	emm	2.1.73
prettier-vscode	esb	6.3.2
vscode-rojo	eva	1.13.1
stylua	Joh	1.2.0
selene-vscode	Kam	1.0.3
rust-analyzer	mat	0.2.583
prettify-json	moh	0.0.3
vsliveshare	ms-	1.0.4131
color-highlight	nau	2.3.0
robloxlsp	Nig	0.15.8
java	red	0.79.1
vscode-yaml	red	0.18.0
vscode-roblox-ts	rob	1.1.2
crates	ser	0.5.9
swdc-vscode	sof	2.5.13
code-spell-checker	str	1.10.2
errorlens	use	3.2.6
vscode-java-debug	vsc	0.33.1

(1 theme extensions excluded)

A/B Experiments

vsliv368:30146709
vsreu685:30147344
python383cf:30185419
pythonvspyt700cf:30270857
pythonvspyt602:30294772
vspor879:30202332
vspor708:30202333
vspor363:30204092
vstes516:30244333
pythonvsnew554cf:30291488
pythontb:30283811
pythonvspyt551:30291414
vspre833:30267464
pythonptprofiler:30281270
vsdfh931cf:30280410
vshan820:30294714
vscoreces:30290705
pythondataviewer:30285071
vscus158:30286553
vscgsv2:30294352

[alexdima]

@ok-nick How are you measuring frame rate? Some of the developer tools, depending on the settings used will reduce the frame rate of the page just by recording the events / stack traces / screenshots / etc.

I personally use this tool to measure frame rate, as it does not impact the frame rate:

[ok-nick]

It is extremely clear visually, while in the editor, that there is a huge performance drop as I scroll. Here is a gif of me scrolling using what you've suggested.

[alexdima]

@ok-nick We have a known problem on Windows that might cause slowness (#107016). Could you please try to close all vscode windows and then launch with code --disable-renderer-accessibility ?

[ok-nick]

Unfortunately it didn't seem to change anything.

[alexdima]

Thank you for trying. Some of the extensions you have installed (e.g. bracket-pair-colorizer-2) might add a lot of text editor decorations which might slow down the editor rendering, depending on your content. Does this reproduce when disabling all extensions?

[ok-nick]

Yes, the issue still happens when all extensions are disabled.

[alexdima]

Thanks for trying. Could you please create a JS CPU profile for the renderer when you are scrolling using these steps?

[ok-nick]

CPU-20210610T180252.zip

[alexdima]

Thank you for the profile. I could not spot anything wrong, it looks like the JS that renders a frame is actually pretty fast on your machine, taking almost always <5ms to render a frame, which should give a great frame rate. IMHO the problem might be somewhere else, not on the renderer process.

@ok-nick To eliminate the problem that this is a GPU / driver issue, could you please also try to close all vscode windows and launch Code.exe --disable-gpu and see if there is any improvement.

Otherwise, this could be a problem with the main process which maybe does not send the user input events to the renderer process fast enough.

[ok-nick]

The --disable-gpu flag allows it to run perfectly, absolutely no lag

[alexdima]

@deepak1556 Any thoughts on how to proceed?

[deepak1556]

Does this issue repro with latest stable 1.74 ?

[ok-nick]

It seems to be fixed! 👍

@deepak1556 Do you know which PR fixed the issue?

[deepak1556]

Not sure, we have had a couple of runtime version updates since the bug reported, very likely fixed through them.

[ok-nick]

The issue still persists. I must've opened it with the --disable-gpu flag which is why I thought it was fixed.

[deepak1556]

@ok-nick can you check if the issue is present with our exploration build that comes with a newer runtime. Thanks!

[vscodenpa]

This issue has been closed automatically because it needs more information and has not had recent activity. See also our issue reporting guidelines.

Happy Coding!