Microsoft.Python.LanguageServer excessive resource usage

Environment data

• VS Code version: 1.30.0
• Extension version (available under the Extensions sidebar): 2018.12.1
• OS and version: macOS 10.14.1
• Python version (& distribution if applicable, e.g. Anaconda): Anaconda, Python 3.7.0
• Type of virtual environment used (N/A | venv | virtualenv | conda | …): conda
• Relevant/affected Python packages and their versions: –

Expected behaviour

Microsoft.Python.LanguageServer is using a reasonable amount of ressources.

Actual behaviour

Microsoft.Python.LanguageServer is using 100%+ CPU Power which is of course draining my battery very fast.

Steps to reproduce:

1. Install and git pull the library fast.ai
2. Open the folder in VSCode

Logs

Output for Python in the Output panel (View→Output, change the drop-down the upper-right of the Output panel to Python)

There's no output generated.

Output from Console under the Developer Tools panel (toggle Developer Tools on under Help)

[ms-python.python]: Command `python.datascience.exportoutputasnotebook` appears multiple times in the `commands` section.
TMSyntax.ts:46 Overwriting grammar scope name to file mapping for scope source.python.
Old grammar file: file:///Applications/Visual%20Studio%20Code.app/Contents/Resources/app/extensions/python/syntaxes/MagicPython.tmLanguage.json.
New grammar file: file:///Users/kai/.vscode/extensions/magicstack.magicpython-1.1.0/grammars/MagicPython.tmLanguage
e.register @ TMSyntax.ts:46
t._handleGrammarExtensionPointUser @ TMSyntax.ts:329
(anonymous) @ TMSyntax.ts:182
e._handle @ extensionsRegistry.ts:114
e.acceptUsers @ extensionsRegistry.ts:98
t._handleExtensionPoint @ extensionService.ts:490
t._onHasExtensions @ extensionService.ts:344
(anonymous) @ extensionService.ts:332
(anonymous) @ errors.ts:237
s.__generator.a.label @ errors.ts:237
s @ errors.ts:237
Promise resolved (async)
c @ errors.ts:237
s @ errors.ts:237
Promise resolved (async)
c @ errors.ts:237
o @ errors.ts:237
o @ errors.ts:237
t._scanAndHandleExtensions @ extensionService.ts:319
(anonymous) @ extensionService.ts:114
requestIdleCallback (async)
t.runWhenIdle @ async.ts:730
(anonymous) @ extensionService.ts:111
Promise resolved (async)
t._startDelayed @ extensionService.ts:109
t @ extensionService.ts:90
t.create @ types.ts:165
e._createInstance @ instantiationService.ts:104
e.createInstance @ instantiationService.ts:69
t.initServiceCollection @ shell.ts:466
t.renderContents @ shell.ts:171
t.open @ shell.ts:528
(anonymous) @ main.ts:147
Promise resolved (async)
(anonymous) @ main.ts:129
Promise resolved (async)
(anonymous) @ main.ts:125
Promise resolved (async)
(anonymous) @ main.ts:116
G @ main.ts:86
(anonymous) @ workbench.js:30
Promise resolved (async)
bootstrapWindow.load.removeDeveloperKeybindingsAfterLoad @ workbench.js:26
exports.load.e @ bootstrap-window.js:123
t._invokeFactory @ loader.js:970
t.complete @ loader.js:980
s._onModuleComplete @ loader.js:1580
s._onModuleComplete @ loader.js:1592
s._onModuleComplete @ loader.js:1592
s._onModuleComplete @ loader.js:1592
s._resolve @ loader.js:1542
s.defineModule @ loader.js:1206
s._onLoad @ loader.js:1283
(anonymous) @ loader.js:1453
e.triggerCallback @ loader.js:594
(anonymous) @ loader.js:588
t.load @ loader.js:745
e.load @ loader.js:588
i @ loader.js:1448
(anonymous) @ loader.js:1456
e.triggerErrorback @ loader.js:601
(anonymous) @ loader.js:588
(anonymous) @ loader.js:751
readFileAfterOpen @ fs.js:420
extensionHost.ts:329 [Extension Host] debugger listening on port 65352
extensionHost.ts:235 Extension Host
extensionHost.ts:236 Debugger listening on ws://127.0.0.1:65352/8dd1261d-3e1b-46fa-95cc-1cad6f5fd490
For help see https://nodejs.org/en/docs/inspector

log.ts:157  INFO no standard startup: not a new window
console.ts:134 [Extension Host] [UriError]: Scheme is missing: {scheme: "", authority: "", path: "", query: "", fragment: ""}
t.log @ console.ts:134
t._logExtensionHostMessage @ extensionHost.ts:453
(anonymous) @ extensionHost.ts:244
emitTwo @ events.js:126
emit @ events.js:214
emit @ internal/child_process.js:772
_combinedTickCallback @ internal/process/next_tick.js:141
_tickCallback @ internal/process/next_tick.js:180
console.ts:134 [Extension Host] Python Extension: Display locator refreshing progress, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Notify locators are locating, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Checking whether locactors have completed locating, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Detected refreshing of Interpreters, Arg 1: {}, Return Value: 
console.ts:134 [Extension Host] Python Extension: Display locator refreshing progress, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Notify locators are locating, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Checking whether locactors have completed locating, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Detected refreshing of Interpreters, Arg 1: {}, Return Value: 
console.ts:134 [Extension Host] Python Extension: Display locator refreshing progress, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Notify locators are locating, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Checking whether locactors have completed locating, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Detected refreshing of Interpreters, Arg 1: {}, Return Value: 
console.ts:134 [Extension Host] Python Extension: Display locator refreshing progress, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Notify locators are locating, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Checking whether locactors have completed locating, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Detected refreshing of Interpreters, Arg 1: {}, Return Value: 
console.ts:134 [Extension Host] Python Extension: Create file systemwatcher with pattern */python
console.ts:134 [Extension Host] Python Extension: Create file systemwatcher with pattern */*/python
console.ts:134 [Extension Host] Python Extension: Display locator refreshing progress, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Notify locators are locating, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Checking whether locactors have completed locating, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Detected refreshing of Interpreters, Arg 1: {}, Return Value: 
console.ts:134 [Extension Host] Python Extension: Display locator refreshing progress, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Notify locators are locating, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Checking whether locactors have completed locating, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Detected refreshing of Interpreters, Arg 1: {}, Return Value: 
console.ts:134 [Extension Host] Python Extension: Display locator refreshing progress, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Notify locators are locating, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Checking whether locactors have completed locating, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Detected refreshing of Interpreters, Arg 1: {}, Return Value: 
console.ts:134 [Extension Host] Python Extension: Register Intepreter Watcher, Arg 1: {"$mid":1,"fsPath":"/Users/kai/Dropbox/SCRATCH/fastai","external":"file:///Users/kai/Dropbox/SCRATCH/fastai","path":"/Users/kai/Dropbox/SCRATCH/fastai","scheme":"file"}, Return Value: 
console.ts:134 [Extension Host] Python Extension: Create file systemwatcher with pattern */python
console.ts:134 [Extension Host] Python Extension: Create file systemwatcher with pattern */*/python
console.ts:134 [Extension Host] Python Extension: Display locator refreshing progress, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Notify locators are locating, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Checking whether locactors have completed locating, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Detected refreshing of Interpreters, Arg 1: {}, Return Value: 
console.ts:134 [Extension Host] Python Extension: Build the workspace interpreter watcher, Arg 1: {"$mid":1,"fsPath":"/Users/kai/Dropbox/SCRATCH/fastai","external":"file:///Users/kai/Dropbox/SCRATCH/fastai","path":"/Users/kai/Dropbox/SCRATCH/fastai","scheme":"file"}, Return Value: UNABLE TO DETERMINE VALUE
console.ts:134 [Extension Host] Python Extension: Register Intepreter Watcher, Arg 1: undefined, Return Value: 
console.ts:134 [Extension Host] Python Extension: Build the workspace interpreter watcher, Arg 1: undefined, Return Value: UNABLE TO DETERMINE VALUE
console.ts:134 [Extension Host] Python Extension: Get Platform Version, , Return Value: {"raw":"18.2.0","major":18,"minor":2,"patch":0,"prerelease":[],"build":[],"version":"18.2.0"}
console.ts:134 [Extension Host] Python Extension: Get language server folder name, , Return Value: "languageServer.0.1.72"
console.ts:134 [Extension Host] Python Extension: Hide locator refreshing progress, , Return Value: 
console.ts:134 [Extension Host] Python Extension: All locators have completed locating, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Checking whether locactors have completed locating, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Hide locator refreshing progress, , Return Value: 
console.ts:134 [Extension Host] Python Extension: All locators have completed locating, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Checking whether locactors have completed locating, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Hide locator refreshing progress, , Return Value: 
console.ts:134 [Extension Host] Python Extension: All locators have completed locating, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Checking whether locactors have completed locating, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Hide locator refreshing progress, , Return Value: 
console.ts:134 [Extension Host] Python Extension: All locators have completed locating, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Checking whether locactors have completed locating, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Hide locator refreshing progress, , Return Value: 
console.ts:134 [Extension Host] Python Extension: All locators have completed locating, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Checking whether locactors have completed locating, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Hide locator refreshing progress, , Return Value: 
console.ts:134 [Extension Host] Python Extension: All locators have completed locating, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Checking whether locactors have completed locating, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Hide locator refreshing progress, , Return Value: 
console.ts:134 [Extension Host] Python Extension: All locators have completed locating, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Checking whether locactors have completed locating, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Hide locator refreshing progress, , Return Value: 
console.ts:134 [Extension Host] Python Extension: All locators have completed locating, , Return Value: 
console.ts:134 [Extension Host] Python Extension: Checking whether locactors have completed locating, , Return Value: 

[keyunjie96]

Is there any chances that this is caused due to security software? (Like antivirus, enterprise Windows, etc)

Not only on Windows, but Mac users also suffer from the Python Language Server.

[kazbeel]

I have created a very simple Python project just to make some tests. And after some time, I can confirm that I only have memory leaks when pointing to a Virtual Environment. At the right moment I change the “python.pythonPath” to the system’s python executable, the memory leak disappears.

I have only tested on Windows.