TS Server takes 100% cpu

[isidorn]

Code insiders helper renderer gets at 100% cpu for the last 3 work days for me.
My clunky reprot steps: just open vscode repository and wait until you can hear your cpu fan.

Let me know what details you would like me to provide. Please do not link me to the performance issue page :)
This was not happening 7 days ago.

[bpasero]

@isidorn but is this using our E8 build or not? And did you make sure it is the renderer process and not some child process within (use our process explorer for that).

[isidorn]

@bpasero it is not the E8 build. But the regular one.
I will use our process explorer tomorrow when this happens again.

[github-actions]

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!

[isidorn]

Ok it is the TS Server

Here is the TS Log

[Info - 07:31:19.334] Starting TS Server
[Info - 07:31:19.334] Using tsserver from: /Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib
[Info - 07:31:19.336] Forking...
[Info - 07:31:19.341] Starting...
[Info - 07:31:19.341] Forking...
[Info - 07:31:19.344] Starting...

@mjbvz please let me know what more data you need. I can repro this every time and hurst my productivity.

[isidorn]

Might it be TS semantic highlighthing that causes 100% cpu?
fyi @aeschli

[aeschli]

@isidorn Try "editor.semanticHighlighting.enabled": false to test that hypothesis.

[isidorn]

@aeschli I am trying it now. We will see tomorrow, since this for some reasons happens once per day.

[github-actions]

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!

[isidorn]

This was not happening with semanticHighlighting disabled.
@aeschli @mjbvz what more data would you like me to provide so we can look into this?

[aeschli]

This will be something the TypeScript team has to look at when they take over our code. Clearly, semantic highlighting is expensive as it involve resolving many symbols. The TypeScript service does not seem to cache very much as @alexdima found in his investigations.

#92789 is the issue for the handover

[isidorn]

@aeschli actually this started reproducing every couple of days even thoough I have semanticHighlighting disabled. Maybe it was happening more often when I had it turned on.
How can I provide more info that could be helpful?

[mjbvz]

@isidorn Is there something that seems to trigger this? For example, running yarn?

[isidorn]

@mjbvz that is a good guess.
I only see this at the start of my work day, and that is typically when I run yarn.
I will try to keep my eyes open when this happens next time, but for now I would blame running yarn

[mjbvz]

Thanks. This could be #98665, which has been fixed upstream by microsoft/TypeScript#37653

I will update us to use the TypeScript 4.0 build with this fix soon. Hopefully that will address the problem

[isidorn]

@mjbvz thanks! Looking forward to the fix.

[primozs]

@mjbvz Hi,
So this is not yet released in TS 3.9.7 right? vscode 1.47.3
I get high cpu on yarn install. like described in #98665

code --status
CPU
108 819 86184 electron_node tsserver.js

[mjbvz]

Closing this for now since the upstream TS has been fixed. Let me know if you still see the problem when using the latest VS Code builds