Bug 413934

Summary: High CPU usage when switching wallpaper as slideshow
Product: [Plasma] plasmashell Reporter: Xwang <xwaang1976>
Component: Image WallpaperAssignee: Marco Martin <notmart>
Status: RESOLVED DUPLICATE    
Severity: normal CC: kishore96, nate, plasma-bugs, sebastien.picavet
Priority: NOR Keywords: regression
Version: 5.17.2   
Target Milestone: 1.0   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed In:
Sentry Crash Report:

Description Xwang 2019-11-08 08:57:00 UTC 
SUMMARY
When I configure the desktop to use images from a folder located on an SSD ext4 drive as wallpaper using a time ordered slideshow which changes image every 10 seconds, I see the CPU usage going up to about 25% (from a base constant level of less than 2%) every time the image is changed (it seems that one of the 4 CPU cores goes to 100%).
If I change the changing rate of images nothing changes (CPU usage continue to goes up  every time the image is changed)


STEPS TO REPRODUCE
1. Set the wallpaper as slideshow every 10 seconds
2. Monitor the CPU usage using sudo top or a plasmoid

OBSERVED RESULT
CPU usage continue to goes up  every time the image is changed

EXPECTED RESULT
Changing a wallpaper image should not require high CPU usage on an i7-6700HQ with 16GB f ram and SSD drive.

SOFTWARE/OS VERSIONS

Linux/KDE Plasma: Archlinux
(available in About System)
KDE Plasma Version: 5.17.2-1
KDE Frameworks Version: 5.63.0
Qt Version: 5.13.2

ADDITIONAL INFORMATION
Comment 1 Nate Graham 2019-12-06 17:22:46 UTC 
Sounds like it's caused by indexing the folder. How many images are in there?
Comment 2 Xwang 2019-12-06 17:52:24 UTC 
62 files (for a total of 4.8 MB)
Comment 3 Bug Janitor Service 2019-12-21 04:33:10 UTC 
Dear Bug Submitter,

This bug has been in NEEDSINFO status with no change for at least
15 days. Please provide the requested information as soon as
possible and set the bug status as REPORTED. Due to regular bug
tracker maintenance, if the bug is still in NEEDSINFO status with
no change in 30 days the bug will be closed as RESOLVED > WORKSFORME
due to lack of needed information.

For more information about our bug triaging procedures please read the
wiki located here:
https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging

If you have already provided the requested information, please
mark the bug as REPORTED so that the KDE team knows that the bug is
ready to be confirmed.

Thank you for helping us make KDE software even better for everyone!
Comment 4 Xwang 2019-12-21 08:53:04 UTC 
I hace already answered to the question.
There are 62 files for a total of 4.8MB of data.
Comment 5 Sébastien P. 2020-01-04 19:12:25 UTC 
Same thing here.
plasmashell process with 100% CPU on one core during the switching of picture.

For me 50Gio for 10929 files.
Note: I have just updated my system from kde-plasma 5.16.5 to 5.17.4.
Comment 6 Sébastien P. 2020-01-04 19:40:33 UTC 
Just see this issue with all his duplicates. I think we can duplicate this one too.

*** This bug has been marked as a duplicate of bug 371455 ***