vscode: Code freezes when it receives focus

Issue Type: Performance Issue

The issue itself is very simple to explain: When VSCode is already up and running and I switch the focus to anonther application (e.g. Browser, File Explorer, …) and then after some time (>~5s) switch focus back to VSCode, the window just freezes for 1-3s before everything is back to normal.
Has happened to me consistently over the last 6 months at least, happened in each and every project.
It is something that is unfortunately not reliable to reproduce. Sometimes I can code a few hours or days, before it hits me, but sometimes it happens very frequent as well.

Only solution right now is to completely restart all VSCode instances.

I did a performance recording as suggested here, and uploaded it to this issue here: vscode-pprof.json.txt

The bug is not related to extensions, since I reproduced it while all extensions were disabled

VS Code version: Code - OSS 1.68.1 (30d9c6cd9483b2cc586687151bcbcd635f373630, 2022-06-16T08:22:04.269Z) OS version: Linux x64 5.15.50-1-lts Restricted Mode: No

System Info

Item	Value
CPUs	AMD Ryzen 7 4800U with Radeon Graphics (16 x 1800)
GPU Status	2d_canvas: enabled canvas_oop_rasterization: disabled_off direct_rendering_display_compositor: disabled_off_ok gpu_compositing: enabled multiple_raster_threads: enabled_on oop_rasterization: disabled_off opengl: enabled_on rasterization: disabled_software raw_draw: disabled_off_ok skia_renderer: enabled_on video_decode: disabled_software video_encode: disabled_software vulkan: disabled_off webgl: enabled webgl2: enabled
Load (avg)	3, 2, 2
Memory (System)	15.00GB (1.28GB free)
Process Argv	–unity-launch
Screen Reader	no
VM	0%
DESKTOP_SESSION	undefined
XDG_CURRENT_DESKTOP	undefined
XDG_SESSION_DESKTOP	undefined
XDG_SESSION_TYPE	wayland

Process Info

CPU %	Mem MB	   PID	Process
    0	   200	  5727	code-oss main
    0	    77	  5730	   zygote
    0	   200	  5756	     gpu-process
    0	    77	  5731	   zygote
    0	     0	  5733	     zygote
    0	    31	 37896	       utility
    0	   108	 38912	       issue-reporter
    0	    92	  5791	   utility-network-service
    0	   261	  5804	   window (backend.go - vision - Code - OSS)
    3	   277	  5805	   window (daemon.go - nline - Code - OSS)
    0	   277	  5811	   window (semanticsegmentationmodel_test.go - nlib - Code - OSS)
    0	   169	  5896	   shared-process
    0	   108	  5975	     ptyHost
    0	     0	  7243	       /usr/bin/bash
    0	     0	  7262	       /usr/bin/bash
    0	     0	  7333	       /usr/bin/bash
    0	     0	 14638	       /usr/bin/bash
    0	    92	  6016	     fileWatcher
    0	    92	  6017	     fileWatcher
    0	    92	 14598	     fileWatcher
    0	    92	 38171	     fileWatcher
    0	     0	 38930	     /usr/bin/ps -ax -o pid=,ppid=,pcpu=,pmem=,command=
    0	   154	  5897	   extensionHost
    0	   184	  6146	     /home/skaldesh/go/bin/gopls -mode=stdio
    0	   154	  5934	   extensionHost
    0	   246	  6420	     /home/skaldesh/go/bin/gopls -mode=stdio
    0	   292	 14514	   window (camera.go - camera - Code - OSS)
    0	   154	 14586	   extensionHost
    0	   230	 14684	     /home/skaldesh/go/bin/gopls -mode=stdio
    1	   138	 38158	   extensionHost
    0	   277	 38435	     /home/skaldesh/go/bin/gopls -mode=stdio

Workspace Info

|  Window (camera.go - camera - Code - OSS)
|  Window (semanticsegmentationmodel_test.go - nlib - Code - OSS)
|  Window (daemon.go - nline - Code - OSS)
|  Window (backend.go - vision - Code - OSS)
|    Folder (camera): 811 files
|      File types: go(79) h(24) cpp(21) yaml(4) md(2) gitignore(1) pprof(1)
|                  tar(1) txt(1) mod(1)
|      Conf files:
|    Folder (nline): 1520 files
|      File types: go(64) xml(8) md(2) npack(2) yaml(2) gitignore(1) iml(1)
|                  json(1) tar(1) txt(1)
|      Conf files: settings.json(1) dockerfile(1)
|    Folder (nlib): 6451 files
|      File types: jpg(5030) go(82) yaml(41) npack(30) h(25) cpp(22) xml(12)
|                  onnx(12) md(9) pt(9)
|      Conf files: launch.json(1)
|      Launch Configs: go
|    Folder (vision): 3619 files
|      File types: qml(578) png(182) qmlc(170) dll(106) o(51) qmltypes(39)
|                  cpp(24) h(18) js(13) go(12)
|      Conf files: makefile(3);

Extensions (8)

Extension	Author (truncated)	Version
systemd-unit-file	coo	1.0.6
dart-code	Dar	3.44.0
go	gol	0.34.1
vscode-simple-icons	Lau	1.16.0
hexeditor	ms-	1.9.7
orbit	r0l	0.0.1
cmake	twx	0.0.17
vscode-todo-highlight	way	1.0.5

About this issue

Original URL
State: closed
Created 2 years ago
Reactions: 3
Comments: 29 (1 by maintainers)

Most upvoted comments

You want to find another, easier solution, without having to reinstall VSCode, I get it. But believe me, you won’t find any.

There actually is an easier workaround. The program files themselves aren’t an issue in any capacity so there is no need to reinstall Code. Deleting the entirety of %AppData%\Code means you lose all workspaces you have to configure again and again. What I tried was more of a drastic “I need to find a solution now” trial and error. While it did work, https://github.com/microsoft/vscode/issues/146737#issuecomment-1153131501 made an excellent point. I completely forgot to revisit this topic but since I have been mentioned here, I’ll leave this bit of information.

Close Code and simply delete the following directories:

Code lacks a method to clear all caches. The user must manually do so to restore expected performance.

icedterminal on Jul 9, 2022

@skaldesh You have to clear the VSCode cache, as I described here https://github.com/microsoft/vscode/issues/146737#issuecomment-1153128058 The slowness/freezing is caused by large amounts of cached files compounding and giving sluggish performance after some time. The only solution I have found was to completely uninstall, remove the cache folders and reinstall VSCode. You already know all of this, but unfortunately we cannot continue commenting in that issue https://github.com/microsoft/vscode/issues/146737 because for some reason someone locked it up.

Anyway, you should have mentioned that issue here and also my response, even if it annoys you having to clean the cache. You want to find another, easier solution, without having to reinstall VSCode, I get it. But believe me, you won’t find any. I’ve been pulling out my hair for many months until I nuked everything and started fresh.

For further info, I’ll post my response from https://github.com/microsoft/vscode/issues/146737 here as well, since that issue is locked:

The solution to get rid of the slowness and get back the snappiness and quick reaction when focusing back to VSCode from another program is to uninstall VSCode, restart the PC and completely remove the folder C:\Users\[User]\AppData\Roaming\Code, which in my case had 380 MB and several thousand files cached in it. The folder has grown so much over 2 years of daily VSCode use, with regular upgrading to newest version as soon as it was released. I’ve also removed the VSCode extensions folder C:\Users\[User]\.vscode, I’m not sure whether that helped or not.

After reinstalling VSCode I had to reconfigure everything from scratch and install all extensions, but the cache folder is now only 80 MB and contains 550 files. Working with VSCode is a breeze again…

*Credit goes to @icedterminal https://github.com/microsoft/vscode/issues/146737#issuecomment-1124494187 - thanks for the idea!

*Cross-referencing possibly related issues, perhaps it helps someone else not noticing this solution: https://github.com/microsoft/vscode/issues/123257 https://github.com/microsoft/vscode/issues/141735 https://github.com/microsoft/vscode/issues/147151 https://github.com/microsoft/vscode/issues/147188

Edit: Slow file open fixed as well - brilliant!

lorand-horvath on Jul 8, 2022