Copilot chat makes vscode unresponsive

[madupuis90]

• Copilot Chat Extension Version: 0.33.4
• VS Code Version: 1.106.3
• OS Version: linux bazzite-dx, KDE Plasma
• Feature (e.g. agent/edit/ask mode): agent
• Selected model (e.g. GPT 4.1, Claude 3.7 Sonnet): Claude Sonnet 4.5
• Logs: I am not sure which logs are needed, there is no error in the copilot logs

Steps to Reproduce:

1. Open a project in vscode
2. Open chat and send a prompt
3. Will make vscode unresponsive - sometimes it recuperates

Description:

VSCode on linux with KDE sometimes becomes unresponsive while interacting with copilot chat. It seems to happen more when it sends a command to the terminal and when it asks permission to run a command (the allow/skip buttons). Sometimes VSCode will become responsive again after 15-60sec). While it is unresponsive everything is frozen, you can't do hotkeys or type anything. The cursor style moves but the cursor style is frozen on whatever it was on at the time of the freeze. I have not notice if it only happens with premium requests.

[johnmeshulam]

This is happening to me as well, sometimes every few hours and sometimes every 2-3 minutes, making vscode with copilot unusable at times. I noticed that when copilot is installed and enabled, sometimes during chat and sometimes randomly when typying in the code editor, the window becomes unresponsive. After ~20 seconds a message pops up asking you to close reopen or keep waiting. Reopening solves the issue however it is extremely interruptive.

Can confirm this started happening to me on version 1.106 as well, although I have since downgraded to 1.105 and experienced similar behavior. This does not seem to occur when copilot is disabled or not installed.

[roblourens]

Woudl appreciate if you can grab a perf trace - https://github.com/microsoft/vscode/wiki/Performance-Issues thanks

[madupuis90]

@roblourens I attached a profile of the running extensions. I am not sure if that is what you asked. I can run other profiles tomorrow if you meant another kind of profiling.

I clicked profiling on a small project (index.html) and asked copilot to create a new page with a bunch of divs. It starts outputing a breakdown of what is it going to do, reading files, etc. then at some point it becomes unresponsive. It looks like the answer has finished loading. I can see the button to keep or discard the changes, but the UI is frozen.
It took about 2 mins before I could click stop recording.

I do not have extensions disabled since the issue only happens when interacting with Github Copilot/Github Copilot Chat. I am also using devcontainers.

Hope this helps a bit:
CPU-20251210T032929.242Z.cpuprofile.txt

[roblourens]

Thanks @madupuis90 but if the window is not responding, I need a trace of the UI, not the extension host. You can open devtools on the window and grab a performance trace from there https://github.com/microsoft/vscode/wiki/Performance-Issues#the-rendererwindow-process-consumes-a-lot-of-cpu

as long as the window does start responding at some point, that should work.

[madupuis90]

Yes that makes sense, I was sure what perf trace you needed since the extension seems to crash the ui. I will generate a trace later tonight

[pfwang80s]

The same issue arises, especially when prompting for a major task and the AI undergoes multiple iterations.

[madupuis90]

The trace I generated is 140mb and it won't let me upload the .json to the issue so I compressed it.

Trace-20251211T202521.tar.gz

In my case it happens when asking simple things in the chat windows. In this case, I had a simple go file that starts a web server (not a real project). I asked it to start create a new page with a game of snake. It did so fairly quickly (no issues there). It was after it was done that my ide becomes unresponsive. It is easy to notice because if my cursor style (hand, pointer, etc.) does not change anymore. Also during this time is doesn't seem like there is any io, network, cpu or gpu work...

Hope this helps. I don't know why the idle frame lasts for so long. Let me know if you need me to provide other traces or run any test

Edit:

It seems to be happening way less, but I was still able to reproduce the same behavior with hardware acceleration disabled and these 2 settings:
"window.dialogStyle": "custom", // uses vscode dialogs instead of Kdialog
"terminal.external.linuxExec": "bash" // helps copilot recognize commands (I think)

One reason why I think KDE might be doing something unexpected is because of the following:

• When I open a small file, make a change and click the "X" button
• Popup appears (Kdialog) asking if I want to save, discard or cancel.
• Both save and discard do what they say and closes the dialog
• Cancel on the other makes the UI unresponsive for 1 second pretty constantly. This is gone with custom dialog

Edit x2:

I may have talked too fast. It still becomes unresponsive very often.

[roblourens]

Thanks for the trace. Yours looks pretty much the same as the trace I got here #268516 (comment) and the issue sounds similar. That issue has some more discussion, I will close this for that one.

[vs-code-engineering]

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!