WSL2 causing high CPU load

[max06]

Version

Microsoft Windows [Version 10.0.22000.376]

WSL Version

• WSL 2
• WSL 1

Kernel Version

5.10.60.1

Distro Version

Ubuntu 18.04

Other Software

No response

Repro Steps

Unsure. Here it's enough to simply have a wsl2 shell open. Funny enough, it's gone for now.

Expected Behavior

Taskmanager showing Vmmem with little to no cpu usage in idle, while a wsl2 shell is open.

Actual Behavior

Taskmanager show(ed) Vmmem with 5-6% constant cpu usage (on a CPU with 32 Threads), high energy consumption and makes the task manager flicker every second.

Processes inside the WSL guest are idling:

USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
root         1  0.0  0.0   1744  1080 ?        Sl   23:17   0:00 /init
root         7  0.0  0.0   1752    68 ?        Ss   23:17   0:00 /init
root         8  0.0  0.0   1752    76 ?        S    23:17   0:00  \_ /init
max06        9  0.0  0.0  22988  5000 pts/0    Ss   23:17   0:00      \_ -bash
max06       98  0.0  0.0  37804  3332 pts/0    R+   23:22   0:00          \_ ps xuaf

Closing the shell (and waiting some seconds) fixes the issue, as well as terminating the guest or the virtual machine.

Diagnostic Logs

I currently hope for someone coming along with "we know that already" and "it's gonna be fixt next update". Otherwise I'm happy to provide whatever you ask for.

[OneBlue]

Thanks for reporting this @max06.

I wonder if this could be caused by wslg.

Can you try to add:

[wsl2]
guiApplications=false

To %userprofile%.wslconfig , then run wsl --shutdown, and start wsl again to see if the issue is still there ?
Also, what's the output of dmesg ?

[ghost]

This issue has been automatically closed since it has not had any author activity for the past 7 days. If you're still experiencing this issue please re-open it.

Thank you!

[craig-matadeen]

Thanks for reporting this @max06.

I wonder if this could be caused by wslg.

Can you try to add:

[wsl2]
guiApplications=false

To %userprofile%.wslconfig , then run wsl --shutdown, and start wsl again to see if the issue is still there ? Also, what's the output of dmesg ?

I'm not sure if it's prudent replying here, but I just wanted you to know that your comment fixed a similar issue that I was having on a clean install of windows 11 where wsl was causing the taskbar notification icons and taskmanager to flicker a lot. Thanks mate.

[cmaart]

Thanks for reporting this @max06.
I wonder if this could be caused by wslg.
Can you try to add:

[wsl2]
guiApplications=false

To %userprofile%.wslconfig , then run wsl --shutdown, and start wsl again to see if the issue is still there ? Also, what's the output of dmesg ?

I'm not sure if it's prudent replying here, but I just wanted you to know that your comment fixed a similar issue that I was having on a clean install of windows 11 where wsl was causing the taskbar notification icons and taskmanager to flicker a lot. Thanks mate.

Having this exact issue as well. Docker using wsl2 starts flickering taskbar and windows after a while with text inputs losing focus. Always have to restart docker/wsl2 to fix it

[levrik]

Also experiencing this issue on Windows 11. Disabling GUI applications fixed it for me as well.

[AndreasSummer]

Have the same problem, most of the time in an RDP Connection.

[levrik]

The issue was gone for me after I updated my Intel graphics drivers to their latest version overriding the Dell-provided ones which were quite outdated.

[max06]

@OneBlue I'm so sorry for the late reply... the issue never appeared again, until just now.

Let's go step by step:

I noticed lags in UI intensive applications (Vivaldi, Bluestacks)
Taskmanager was visibly refreshing the views (all of them) every second, with a short white empty screen between each frame.

I closed all the suspect applications: Vivaldi, VSCode, Windows Terminal, no improvements.

I reopened Vivaldi to look for this issue. I also opened a fresh windows terminal (powershell) to shutdown the wsl2 instance. The flickering disappeared.

Trying to reproduce the issue: Opened a tab with my Ubuntu WSL2 instance in Windows terminal. Flickering is back. Also the WSL2 instance showed a memory consumption of around 2GB, increasing tendency.

Found the question about dmesg in this issue, executed it inside my ubuntu instance:

[   20.494750] weston[1140]: segfault at 7fec60021000 ip 00007feca331c673 sp 00007ffc3efe3d08 error 4 in libc-2.28.so[7feca31de000+14b000]
[   20.494757] Code: 0f 18 8e 00 01 00 00 0f 18 8e 40 01 00 00 0f 18 8e 80 01 00 00 0f 18 8e c0 01 00 00 c5 fe 6f 06 c5 fe 6f 4e 20 c5 fe 6f 56 40 <c5> fe 6f 5e 60 48 81 c6 80 00 00 00 48 81 ea 80 00 00 00 c5 fd e7
[   20.494763] potentially unexpected fatal signal 11.
[   20.494764] CPU: 28 PID: 1140 Comm: weston Not tainted 5.10.102.1-microsoft-standard-WSL2 #1
[   20.494770] RIP: 0033:0x7feca331c673
[   20.494772] Code: 0f 18 8e 00 01 00 00 0f 18 8e 40 01 00 00 0f 18 8e 80 01 00 00 0f 18 8e c0 01 00 00 c5 fe 6f 06 c5 fe 6f 4e 20 c5 fe 6f 56 40 <c5> fe 6f 5e 60 48 81 c6 80 00 00 00 48 81 ea 80 00 00 00 c5 fd e7
[   20.494774] RSP: 002b:00007ffc3efe3d08 EFLAGS: 00010286
[   20.494776] RAX: 00007fec5bffe01e RBX: 00005598eba89630 RCX: 00007fec5bffdff0
[   20.494778] RDX: fffffffffdfde070 RSI: 00007fec60020f92 RDI: 00007fec5e01ffa0
[   20.494779] RBP: 00007fec68000af0 R08: fffffffffffffffe R09: 0000000000000000
[   20.494780] R10: 00007fec5bffe010 R11: 00007fec5bffe01e R12: 00007fec5dfff010
[   20.494782] R13: 00000000018c04ae R14: 00007ffc3efe3d40 R15: 0000000000000000
[   20.494783] FS:  00007feca2949900 GS:  0000000000000000

repeating every 900ms.

Copied whole output. Noticed, my vscode was still running with one window, telling me it's taking longer to close. I can't tell if that window was connected to WSL before. Force closing it stopped the flickering, and I'm not able to reproduce it now again.

A fresh dmesg dump doesn't show the terminating weston anymore.

I can't tell if disabling the GUI extensions for WSL would improve anything here, but a connection to VSCode seems to be likely.

[levrik]

@max06 With that additional information, maybe you could re-open the issue so someone from MS could notice it?

[max06]

@levrik I'd love to, but I don't have the privileges for that...

[levrik]

@max06 That's weird... I was guessing so from #7893 (comment).

[max06]

I hope @OneBlue can reopen it 😅

[OneBlue]

Thanks for reporting this @max06. Based on the logs it looks like weston is crashing. If it's crashing in a loop that would explain the CPU consumption.

I'd recommend creating a wslg issue for this

[max06]

@OneBlue Thank you for your reply!

The more interesting question is: Why is weston even running when there's no GUI application using it? Thought it would get started on first use.

[OneBlue]

It's always started when gui apps are enabled. There are no easy way to do that 'on-demand' since GUI apps will expect the X11 socket to be already present when they start

[max06]

Gotcha. Disabling weston would obviously solve this issue, but then I can't use gui apps (if I'd want to). Maybe remotely related: Is weston also used if I'm running a regular Hyper-V VM with Linux and the enhanced session mode?

[OneBlue]

No, these two things are completely different.