Legacy Python jedi language server takes ~100% CPU while debugging

[cuteufo]

This is a copy of the issue at here. They suggested me to raise the issue here and closed that one.

Version: 1.46.1
Commit: cd9ea64
Date: 2020-06-17T21:17:14.222Z
Electron: 7.3.1
Chrome: 78.0.3904.130
Node.js: 12.8.1
V8: 7.8.279.23-electron.0
OS: Darwin x64 19.5.0

Steps to Reproduce:

Use default language server "Jedi". Start debugging my project.
My project is running as HTTP Server taking POST request, processing request, and sending response back. While debugging, the code can be run line by line smoothly, no hanging or deadlocking, but a python process is running and taking up to ~100% CPU

And this is the ps info of this process:

In most cases, this python process keeps high CPU consumption until I stop debugging, while occasionally it just won't go low unless I exit VSCode.

After I change language server to "Microsoft", this situation hasn't happened so far.

Does this issue occur when all extensions are disabled?: Yes. With Jedi language server, after I disabled all extensions other than Python extension, this issue still occurs.

[kimadeline]

Hi @cuteufo, thank you for reaching out!

We haven't changed anything Jedi-related in the last few releases, does it happen only when debugging? Can you reproduce it when only using built-in Python packages, or does it happen when you use specific packages?

Ultimately completion.py is going to be deprecated in favour of #11995, feel free to upvote it to help us prioritize it.

Thank you!

[cuteufo]

I cannot reproduce it on every projects. In this particular project, it uses following non built-in packages:

mysql
schema
extract_msg
lxml
matplotlib
openpyxl
xlrd

I debug the code by stepping over each line, and step into at some critical functions. What I found odd is that each time I step over one line, the 'python 3.7' process will show up and take up CPU at 100% for around 35 minutes and get back to normal. If I continuously step over a number of lines, that process will accumulate the "show-up" time. That might explain why it could keep hi-CPU usage for a long time because sometimes I could do a very lengthy step-over's or step-into's.

[kimadeline]

Do you get high CPU usage when you're not debugging as well?

[cuteufo]

No, or not that I can notice. Kim-Adeline Miguel <notifications@github.com>于2020年6月26日 周五12:03写道：

…

Do you get high CPU usage when you're not debugging as well? — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#12522 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AFJY6537RRTB5MZC3USWWTLRYTWJDANCNFSM4OGB7BPA> .

[kimadeline]

Strange 🤔 In any case, the plan for the extension is to get rid of completion.py in #11995 (feel free to give it a 👍 if you want to see it implemented sooner than later), so I'm closing in favour of it. In the meantime, using the Microsoft Python Language Server (as you already do) is a workaround.

[mindovermiles262]

I've been experiencing this issue too. The only "python" process running is as follows:

$ ps aux | grep -i python
ME            73133 101.5  0.1  5952000  39380   ??  R     2:53PM   6:16.46 /Users/ME/.asdf/installs/python/3.7.7/Python.framework/Versions/3.7/Resources/Python.app/Contents/MacOS/Python /Users/ME/.vscode/extensions/ms-python.python-2021.3.680753044/pythonFiles/run-jedi-language-server.py

Pings CPU at 102%. It's happened twice in two days now. MacOS 11.2.3 (20D91) "Big Sur" as well as on Catalina (I updated my system between the two times this happened)

VSCode was not running at the time that this maxing out was happening. I'll try to recreate it.

[anfragment]

Also experiencing this on Ubuntu 20.10. Didn't debug anything, multiple run-jedi-language-server.py processes were just left hanging after closing VSCode and were using >100% of the CPU.