[plasmashell] [Bug 393438] New: High cpu usage when idling

[Zakhar]

https://bugs.kde.org/show_bug.cgi?id=393438

Bug ID: 393438
Summary: High cpu usage when idling
Product: plasmashell
Version: master
Platform: Gentoo Packages
OS: Linux
Status: UNCONFIRMED
Severity: normal
Priority: NOR
Component: general
Assignee: ***@davidedmundson.co.uk
Reporter: ***@gmail.com
CC: plasma-***@kde.org
Target Milestone: 1.0

Created attachment 112200
--> https://bugs.kde.org/attachment.cgi?id=112200&action=edit
perf record --call-graph dwarf /usr/bin/plasmashell

even laptop fans kick up after a while. ~15% constant cpu use while idling on
average

[b***@kde.org]

https://bugs.kde.org/show_bug.cgi?id=393438

***@heriban.net changed:

What |Removed |Added
----------------------------------------------------------------------------
CC| |***@heriban.net

--- Comment #1 from ***@heriban.net ---
Note sure if the exact same issue :
I was also having ridiculous cpu usage with plasma (30% on all cores). Upon
closer inspection, I noticed a few coredumps in HTOP.

Looking at coredumpctl -r list , it was filled with :

Tue 2018-04-24 14:13:32 JST 14647 1000 1001 6 present
/usr/bin/kactivitymanagerd

About three per second !

pkill -f kactivitymanagerd stopped the coredumps and high cpu usage.

[UberPanda]

https://bugs.kde.org/show_bug.cgi?id=393438

--- Comment #2 from UberPanda <***@heriban.net> ---
(In reply to UberPanda from comment #1)

Post by b***@kde.org
I was also having ridiculous cpu usage with plasma (30% on all cores). Upon
closer inspection, I noticed a few coredumps in HTOP.
Tue 2018-04-24 14:13:32 JST 14647 1000 1001 6 present
/usr/bin/kactivitymanagerd
About three per second !
pkill -f kactivitymanagerd stopped the coredumps and high cpu usage.

Forgot to mention : HD4600 GPU with intel i7 4600M on manjaro KDE with kernel
4.14 and xf86-video-amdgpu drivers

[Zakhar]

https://bugs.kde.org/show_bug.cgi?id=393438

--- Comment #3 from Zakhar <***@gmail.com> ---
(In reply to UberPanda from comment #1)

Post by b***@kde.org
pkill -f kactivitymanagerd stopped the coredumps and high cpu usage.

Running it slighty reduces cpu usage and then it goes back to the normal ~15 -
30% wilst idling because kactivitymanagerd just respawns or at least I can
constantly kill it with pkill without it telling me it is not running.

[UberPanda]

https://bugs.kde.org/show_bug.cgi?id=393438

--- Comment #4 from UberPanda <***@heriban.net> ---
Created attachment 112208
--> https://bugs.kde.org/attachment.cgi?id=112208&action=edit
First screenshot of blinking activity settings

[UberPanda]

https://bugs.kde.org/show_bug.cgi?id=393438

--- Comment #5 from UberPanda <***@heriban.net> ---
Created attachment 112209
--> https://bugs.kde.org/attachment.cgi?id=112209&action=edit
Second screenshot of blinking activity settings

[UberPanda]

https://bugs.kde.org/show_bug.cgi?id=393438

--- Comment #6 from UberPanda <***@heriban.net> ---
(In reply to Zakhar from comment #3)

Post by UberPanda
(In reply to UberPanda from comment #1)

Post by b***@kde.org
pkill -f kactivitymanagerd stopped the coredumps and high cpu usage.

Running it slighty reduces cpu usage and then it goes back to the normal ~15
- 30% wilst idling because kactivitymanagerd just respawns or at least I can
constantly kill it with pkill without it telling me it is not running.

Mine does not restart. However, I noticed that when launching the activity
settings through the application launcher, kactivitymanagerd is back and the
window is error blinking (see attached screenshot). My guess is something is
really broken with the activity manager.

[Zakhar]

https://bugs.kde.org/show_bug.cgi?id=393438

--- Comment #7 from Zakhar <***@gmail.com> ---
I should add this problem existed in the last stable release pre 5.45.0 however
cpu usage was not as high as it is with this revision. I should mention the new
revision plugged some serious memory leaks but unfortunately didn't address the
cpu usage.

[David Edmundson]

https://bugs.kde.org/show_bug.cgi?id=393438

--- Comment #8 from David Edmundson <***@davidedmundson.co.uk> ---
What Qt version?

[UberPanda]

https://bugs.kde.org/show_bug.cgi?id=393438

--- Comment #9 from UberPanda <***@heriban.net> ---
(In reply to David Edmundson from comment #8)

Post by David Edmundson
What Qt version?

5.10.1-1 in my case

[Zakhar]

https://bugs.kde.org/show_bug.cgi?id=393438

--- Comment #10 from Zakhar <***@gmail.com> ---
Qt 5.9.5

[UberPanda]

https://bugs.kde.org/show_bug.cgi?id=393438

--- Comment #11 from UberPanda <***@heriban.net> ---
I think I found a way to brute force a fix :
In systemctl, the error boils down to :

KActivities: Database can not be opened in WAL mode. Check the SQLite version
(required >3.7.0). And whether your filesystem supports shared memory

I just entirely deleted .local/share/kactivitymanagerd/resources/

and rebooted. The bug did not reappear afterwards (it's been an hour now).