Endless 100% CPU when search/replace many TS files at once

• VSCode Version: insiders
• OS Version: macOS 10.14

Steps to Reproduce:

1. open the vscode workspace
2. search for “copyright” in *.ts
3. replace with “copyright2”
4. run and wait

=> the TS extensions seems to go up to a 100% and stays there without ever recovering.

Full command line:

bpasero 78619 100.1 11.0 6870176 1840020 ?? R 7:14AM 2:13.12 /Applications/Visual Studio Code - Insiders.app/Contents/Frameworks/Code - Insiders Helper.app/Contents/MacOS/Code - Insiders Helper /Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/extensions/node_modules/typescript/lib/tsserver.js --useInferredProjectPerProjectRoot --enableTelemetry --cancellationPipeName /var/folders/w_/xgfzkgq14jv_ykk2lm0k_h5c0000gn/T/vscode-typescript/tscancellation-43d76d57848697e4dfca.tmp* --locale en --noGetErrOnBackgroundUpdate

[roblourens]

Here is the old discussion: https://github.com/microsoft/vscode/issues/89300

The impact is bad and surprising to extension developers, it would be great if we could open a model in a lightweight way that doesn’t get broadcast to the world since we know we will immediately close it. But if extensions want to participate in opening and editing and saving then it might also be surprising to not find out about it.

[pladaria]

We have a TS repo with few thousand files, we were getting 100% usage in several cores and the problem was caused by:

"typescript.tsserver.experimental.enableProjectDiagnostics": true,

That was enabled in our workspace config.

This configuration makes the eslint extension go crazy by constantly checking files (doesn’t seem to end). This was barely noticeable on a 16 core machine but puts a 2015 macbook pro on fire.

Hope this helps someone