Bug 439361

Summary: Plasma Notification slows down apps refresh rate
Product: [Plasma] plasmashell Reporter: shops
Component: NotificationsAssignee: Kai Uwe Broulik <kde>
Status: RESOLVED DUPLICATE    
Severity: normal CC: nate, plasma-bugs-null
Priority: NOR    
Version First Reported In: 5.22.1   
Target Milestone: 1.0   
Platform: openSUSE   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description shops 2021-07-01 08:26:14 UTC 
On my systems the refresh rate drops significantly while a plasma notification is shown on the screen so that the system feels super slow then. I don't know the boundary condition, but I can describe some way where at least I can somehow observe and reproduce it.

STEPS TO REPRODUCE
1. I have a Spotify instance open (flatpak)
2. I have a Firefox instance open
3. Open a Website in Firefox and scroll threw it (works fine)
4. Change the title, so that a notification is shown
5. Scroll the website while the notification is present: It is stuttering until the notification has purged

(I was also able to make that happen with a notification caused by a "ping" from the mobile in kde connect instead of Spotify and observed the stuttered scrolling also e. g. in Dolphin. Also videos are stuttering while a notification is present on screen.)

OBSERVED RESULT
System is stuttering

EXPECTED RESULT
System should stay smooth

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: openSUSE Tumbleweed 20210626
(available in About System)
KDE Plasma Version: 5.22.1
KDE Frameworks Version: 5.83.0
Qt Version: 5.12.2

Kernel 5.12.12-1
X11
GeForce GTX 1070
If this could be a reproduction criteria: widescreen Display with high resolution (5120x1440)

Addition: Sometimes I have the feeling that a similar slow down is observed when starting new apps. But there I have difficulties to reproduce up to now...)
Comment 1 Kai Uwe Broulik 2021-07-01 08:51:52 UTC 
You can simulate notifications by using
$ notify-send foo bar

Does this also happen with composting disabled? Does it happen with blur and contrast effects disabled?
Comment 2 shops 2021-07-01 09:12:12 UTC 
I tested what you suggested:

- With compositor disabled it does not happen.

- Before changing Blur and Background contrast settings: They have a "semi-ticked" state in my system settings. What could that mean? Could that be some state from a older version which causes trouble? https://cloud.10hoch-6.de/index.php/s/ZoMSgffs6NzFyz7
Comment 3 Nate Graham 2021-07-29 19:14:27 UTC 

*** This bug has been marked as a duplicate of bug 414785 ***