Bug 499991 - Power Management page in System Settings hangs when using certain font size and zh_CN.UTF-8 system locale
Summary: Power Management page in System Settings hangs when using certain font size a...
Status: RESOLVED DUPLICATE of bug 499773
Alias: None
Product: systemsettings
Classification: Applications
Component: kcm_powerdevil (show other bugs)
Version: 6.3.0
Platform: Arch Linux Linux
: NOR normal
Target Milestone: ---
Assignee: Plasma Bugs List
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2025-02-13 14:21 UTC by Ye Jingchen
Modified: 2025-03-25 22:14 UTC (History)
8 users (show)

See Also:
Latest Commit:
Version Fixed In:
Sentry Crash Report:


Attachments
empty power management page in system settings (61.58 KB, image/webp)
2025-02-13 14:21 UTC, Ye Jingchen
Details
flamegraph under zh_CN.UTF-8 locale (1.98 MB, image/svg+xml)
2025-02-13 14:24 UTC, Ye Jingchen
Details

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Description Ye Jingchen 2025-02-13 14:21:09 UTC
Created attachment 178280 [details]
empty power management page in system settings

SUMMARY
The "Power Management" page in System Settings will hang, causing 100% single thread CPU usage, if the system is using LANG=zh_CN.UTF-8 locale, and font size in System Settings "Text & Fonts" page is set exactly as follows:

General: 11pt
Fixed width: 11pt
Small: 9pt
Toolbar: 11pt
Menu: 11pt
Window title: 11pt

Font families and anti-aliasing settings don't seem to matter.

STEPS TO REPRODUCE
1. Ensure zh_CN.UTF-8 locale is available (`locale -a` output contains `zh_CN.utf8`). On Arch Linux this means uncommenting zh_CN.UTF-8 in /etc/locale.gen and run `locale-gen`.
2. Change font size in System Settings as above
3. Close System Settings, launch it with `LANG=zh_CN.UTF-8  systemsettings`
4. Navigate to "Power Management", see it hang.

OBSERVED RESULT
Right side is empty (see screenshot), 100% CPU usage on a single core.

EXPECTED RESULT
Opens Power Management normally

SOFTWARE/OS VERSIONS
Operating System: Arch Linux 
KDE Plasma Version: 6.3.0
KDE Frameworks Version: 6.10.0
Qt Version: 6.8.2
Kernel Version: 6.13.2-arch1-1 (64-bit)
Graphics Platform: Wayland
Processors: 16 × AMD Ryzen 7 PRO 6850HS with Radeon Graphics
Memory: 14.9 GiB of RAM
Graphics Processor: AMD Radeon Graphics

ADDITIONAL INFORMATION
LANG=C.UTF-8 or LANG=en_US.UTF-8 are unaffected by this, but LANG=ja_JP.UTF-8 is affected.
Comment 1 Ye Jingchen 2025-02-13 14:24:06 UTC
Created attachment 178281 [details]
flamegraph under zh_CN.UTF-8 locale

I also captured a flamegraph using cargo-flamegraph[1], not sure if it helps.

1. https://github.com/flamegraph-rs/flamegraph
Comment 2 Nate Graham 2025-02-18 17:18:03 UTC
I can reproduce the issue with those exact settings and running `LANGUAGE=zh_CN.UTF-8 systemsettings`.
Comment 3 Jeff Huang 2025-02-19 08:01:01 UTC
I can reproduce this issue also for zh_TW.UTF-8 locale.
Comment 4 John Kizer 2025-03-21 18:35:53 UTC
*** Bug 500933 has been marked as a duplicate of this bug. ***
Comment 5 Nate Graham 2025-03-25 22:14:04 UTC
*** This bug has been marked as a duplicate of bug 499773 ***