File watcher consumes lots of CPU in large TS projects

[kamax1]

Type: Performance Issue

Hello! After latest update vscode stared using 100% cpu for each window. I found that it caused by fileWatcher process. I have a very large project but it was fine before the update. Could you fix it pls. Thanks!

VS Code version: Code 1.90.0 (Universal) (89de5a8, 2024-06-04T19:34:44.157Z)
OS version: Darwin arm64 23.4.0
Modes:

System Info

Item	Value
CPUs	Apple M3 Pro (12 x 2400)
GPU Status	2d_canvas: enabled canvas_oop_rasterization: enabled_on 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: enabled webgl: enabled webgl2: enabled webgpu: enabled
Load (avg)	4, 4, 4
Memory (System)	36.00GB (2.59GB free)
Process Argv
Screen Reader	no
VM	0%

Process Info

CPU %	Mem MB	   PID	Process
    2	   221	 95859	code main
    0	   111	 95860	   gpu-process
    0	    37	 95861	   utility-network-service
    0	   848	 95862	window [1] (file1.ts — project1)
    0	   627	 95863	window [2] (file2.ts — project2)
    0	   147	 96052	shared-process
  100	   922	 96053	fileWatcher [2]
  101	   958	 96065	fileWatcher [1]
    0	   295	 96155	extensionHost [2]
    0	   147	 96174	     electron-nodejs (tsserver.js )
    0	  2175	 96177	     electron-nodejs (tsserver.js )
    0	    74	 96429	       electron-nodejs (typingsInstaller.js typesMap.js )
    0	    74	 96282	     electron-nodejs (eslintServer.js )
    0	    74	 96283	     electron-nodejs (ya-make-lsp.js )
    0	   111	 96284	     /Applications/Visual Studio Code.app/Contents/Frameworks/Code Helper (Plugin).app/Contents/MacOS/Code Helper (Plugin) /Users/buckster/.vscode/extensions/streetsidesoftware.code-spell-checker-3.0.1/packages/_server/dist/main.cjs --node-ipc --clientProcessId=96155
    0	    74	 96285	     electron-nodejs (start-server.js )
    0	    74	 96960	     /Applications/Visual Studio Code.app/Contents/Frameworks/Code Helper (Plugin).app/Contents/MacOS/Code Helper (Plugin) /Applications/Visual Studio Code.app/Contents/Resources/app/extensions/json-language-features/server/dist/node/jsonServerMain --node-ipc --clientProcessId=96155
    0	    74	 96156	ptyHost
    0	     0	 96162	     /bin/zsh -il
    0	     0	 96163	     /bin/zsh -il
    0	     0	 96168	     /bin/zsh -il
    0	   295	 96157	extensionHost [1]
    0	   147	 96197	     electron-nodejs (tsserver.js )
    0	  2212	 96198	     electron-nodejs (tsserver.js )
    0	    74	 96412	       electron-nodejs (typingsInstaller.js typesMap.js )
    0	   221	 96290	     electron-nodejs (eslintServer.js )
    0	    74	 96294	     electron-nodejs (ya-make-lsp.js )
    0	   258	 96296	     /Applications/Visual Studio Code.app/Contents/Frameworks/Code Helper (Plugin).app/Contents/MacOS/Code Helper (Plugin) /Users/buckster/.vscode/extensions/streetsidesoftware.code-spell-checker-3.0.1/packages/_server/dist/main.cjs --node-ipc --clientProcessId=96157
    0	    74	 96297	     electron-nodejs (start-server.js )

Extensions (18)

Extension	Author (truncated)	Version
vscode-eslint	dba	2.4.4
EditorConfig	Edi	0.16.4
pi-helper	ela	0.0.41
prettier-vscode	esb	10.4.0
vscode-language-pack-ru	MS-	1.89.2024050109
remote-ssh	ms-	0.110.1
remote-ssh-edit	ms-	0.86.0
remote-explorer	ms-	0.4.3
sftp	Nat	1.16.3
vscode-yandex-arc	per	0.277.0
code-spell-checker	str	3.0.1
code-spell-checker-russian	str	2.2.2
vscode-stylelint	sty	1.4.0
language-stylus	sys	1.16.0
errorlens	use	3.18.0
intelliboba	vik	0.9.8
sync-rsync	vsc	0.36.0
pretty-ts-errors	Yoa	0.5.4

[bpasero]

Is this with a TypeScript workspace? Does it get better if you configure typescript.tsserver.experimental.useVsCodeWatcher: false?

[kamax1]

Is this with a TypeScript workspace? Does it get better if you configure typescript.tsserver.experimental.useVsCodeWatcher: false?

Yep, i have a ts project. That setting really helped, thanks)

[bpasero]

@kamax1 would I be able to reproduce this issue if you gave me instructions how to get to the same workspace?

[kamax1]

@kamax1 would I be able to reproduce this issue if you gave me instructions how to get to the same workspace?

unfortunately, i'm not able to share my repo. But i've reproduced it on several large projects so i suppose that it should be reproducable on any large TS project (mine have ~40k files)

[bpasero]

@kamax1 it cannot be so obvious to reproduce though, VS Code is a fairly large TS project where I am not seeing it (also as far as I know, not anyone from our team).

Is it possible there are any cyclic symbolic links in your workspace?

[smishenk]

+1 for this issue.

I'm working on a huge TS project and Remote-SSH to it from MacOS laptop to Linux machine.
Started having troubles since 1.89 version (downgrade to 1.88 solved the problem): VSCode becomes "unresponsive" quite fast - as soon as TS features finish initialization, IDE fails to open any other files/directories, progress bars at the top of file editor and explorer run indefinitely. Also, it somehow seems to be related to arm-based MacOS laptops, cause I only encounter this issue on my MacBook Air M2, while MacBook Pro 19 with Intel processor didn't run into any issues even with 1.89 version. Although I can't confirm that experimental watcher was enabled on Intel Mac last time I checked and I'm not able to re-test it anymore. Anyway, only those of my colleagues who are on arm-based Macs complained.

Is it possible there are any cyclic symbolic links in your workspace?

Speaking of my project - yes, it's highly possible. Yet, I cannot say for sure.

Does it get better if you configure typescript.tsserver.experimental.useVsCodeWatcher: false?

Solved the problem for me as well

[bpasero]

Can people that are impacted here do the following:

• open said workspace in VS Code (ensure typescript.tsserver.experimental.useVsCodeWatcher is configured to true)
• wait for the file watcher process to have settled to 0% (this can take time)
• run "Developer: Set Log Level..." and pick "Trace"
• open the "Output" panel
• from the dropdown pick "File Watcher" channel
• Copy the output you see into a response here

This will print information about how many requests for file watching were sent to the file watcher process. I would expect this to be in the number of thousands.

[smishenk]

Can people that are impacted here do the following:

• open said workspace in VS Code (ensure typescript.tsserver.experimental.useVsCodeWatcher is configured to true)
• wait for the file watcher process to have settled to 0% (this can take time)
• run "Developer: Set Log Level..." and pick "Trace"
• open the "Output" panel
• from the dropdown pick "File Watcher" channel
• Copy the output you see into a response here

This will print information about how many requests for file watching were sent to the file watcher process. I would expect this to be in the number of thousands.

In my case it only displays local file watchers/requests. Either because it does not trace remote-SSH processes at all or it cannot get info from VSCode server since that connection "hangs up". Any other ideas how I may trace this data from remote VSCode server?

[bpasero]

Oh yeah sorry, I forgot that it will only report local watchers...

[kamax1]

@kamax1 it cannot be so obvious to reproduce though, VS Code is a fairly large TS project where I am not seeing it (also as far as I know, not anyone from our team).

Is it possible there are any cyclic symbolic links in your workspace?

Yes, looks like so, with have a lot of symlinked packages and looks like some of them are cycled

[bpasero]

There was 1 performance related fix for file watching pushed yesterday that is included in our insiders build today. I would be curious if people could try it out and report back. You can give our preview releases a try from: https://code.visualstudio.com/insiders/

[smishenk]

There was 1 performance related fix for file watching pushed yesterday that is included in our insiders build today. I would be curious if people could try it out and report back. You can give our preview releases a try from: https://code.visualstudio.com/insiders/

I've checked insiders build on my project. Unfortunately, the issue is still there :(

[bpasero]

@smishenk when you say its a huge project, does it have many TS projects inside?

[smishenk]

@smishenk when you say its a huge project, does it have many TS projects inside?

Well, it does have some TS subprojects, yet I don't think that it matters in any way, cause the main part (~85% of TS code) is single TS project and, as I see in VSCode footer, TS server initializes separately for each opened project, while I have issues right after initialization of main part.

When I say it's a huge project, I say we have to raise memory consumption limit for TS server up to 6 Gb:
"typescript.tsserver.maxTsServerMemory": 6144
Otherwise, TS server fails to start x)

[bpasero]

@smishenk is that project open source for me to play with?

Does the CPU eventually settle or stay high?

[smishenk]

@smishenk is that project open source for me to play with?

You would have a link already, if it was ;)

Does the CPU eventually settle or stay high?

I can't say anything about that for now, cause I have issues with remote SSH development. Local CPU does almost nothing and I cannot profile remote machine since SSH connection hangs up the moment VSCode loads it with its processes.
I'll try to reproduce the same behavior locally later and collect profile info you asked about.

[smishenk]

@bpasero
I couldn't reproduce the same behavior locally, so it seems that this issue isn't related to the size of a project. The only difference between my local repo and remote is that remote has symlinked directories (and I can't do anything with that, cause this is how our projects are organized on dev-machines). Anyway, I managed to profile dev-machine using top and here are some results:

• If we wait patiently for the first lags to pass (approximately 20-25 mins), then further slowdowns are resolved much faster (10-15 seconds);
• VSCode process that performs those tasks seems to load only single CPU core, while other VSCode processes doesn't hesitate at all;
• Worth to mention that eventually that load comes to 0-1% when task is completed and stays at 100% (single-core) while task is performed;
• VSCode process profiling still doesn't work, so I can't say for sure which exactly process is that :(

I'm wondering if I could enable some tracing/logs of TS server on remote-SSH to get detailed info

[bpasero]

/duplicate #216825

[vscodenpa]

Thanks for creating this issue! We figured it's covering the same as another one we already have. Thus, we closed this one as a duplicate. You can search for similar existing issues. See also our issue reporting guidelines.

Happy Coding!