weather-widget causes high CPU after activity switch since Qt 5.9

[robby81]

lease have a look into that: https://bugs.kde.org/show_bug.cgi?id=381280

[kotelnik]

Thanks for directing me to the bug. I've redirected wether-widget specific situations here. If the issue is still present, please tell me more - distro, versions, so I can test e.g. in virtualbox.

[robby81]

The issue is still here with latest git version compiled locally under the latest openSUSE Tumbleweed snapshot with Qt 5.9.1, Frameworks 5.37 and Plasma 5.10.5. After compiling I can add the widget to the panel (upper edge here), switch to compact mode, restart the machine. Then I check cpu loads (first it is fine) then I switch to another acitivity and the cpu load for kwin, plasma and X goes up to >10% and stays there until plasmashell restart.

[kotelnik]

I've installed openSUSE Thumbleweed on my virtualbox but so far couldn't replicate the issue you are describing. Here is what I've done exactly:

1. Downloaded Network CD of openSUSE Tumbleweed
2. Installed as a VirtualBox guest (by base system is Arch Linux btw.)
3. Default install (only without dedicated /home partition and used ext4 instead of btrfs)
4. Because by default there are no devel packages installed, I've installed these:

• git
• extra-cmake-modules
• libqt5-qtbase-devel
• libqt5-qtdeclarative-devel
• plasma-framework-devel

5. Then I've git-cloned this widget and performed:

$ cd plasma-applet-weather-widget
$ mkdir build
$ cd build
$ cmake .. -DCMAKE_INSTALL_PREFIX=/usr -DCMAKE_BUILD_TYPE=Release
$ make
$ sudo make install

6. Added these widgets to the panel:

• Weather Widget
• CPU Monitor
• Activity Pager

7. Then moved the panel to the upper edge, locked widgets.
8. Added one activity.
9. Reboot
10. Did the activity switching while observing CPU load.

See screenshots (4):

1. initial screen after reboot

2. after switching to the other activity

3. after weather-widget location change (from Bonn to New York)

4. after switching back to the first activity

Should I do something differently to trigger the issue?

To further narrow down the issue:

• make sure you have only one Weather Widget install (meaning remove the kde-store version if there is one)
• try removing ~/.cache/, then reboot and test again

[robby81]

Could you please try to add a folderview widget to each of the activities and set them up to show files linked to the current activity. Then test again. I tried to add widget per widget as a new user and after adding these I could reproduce the bug even without the weather-widget under plasma 5.10.95 with frameworks 5.38.