#745875 /usr/bin/kwin: KWin consumes 100% of one of my CPUs while idle

Package:
kde-window-manager
Source:
kwin
Submitter:
Marc Coll
Date:
2023-04-26 09:33:14 UTC
Severity:
normal
#745875#5
Date:
2014-04-26 08:19:47 UTC
From:
To:
KWin consumes 100% of one of my CPUs while the computer is idle. I suspect it
has something to do with the screensaver, because it stops doing so whenever I
press any key or move the mouse. I made a small script that run top every 10
seconds and logs it to a file, and I got lots of this kind of reports:


top - 09:47:36 up 18:13,  5 users,  load average: 1,00, 1,03, 1,05
Tasks: 139 total,   3 running, 136 sleeping,   0 stopped,   0 zombie
%Cpu(s):  9,4 us, 28,7 sy,  0,5 ni, 60,4 id,  0,8 wa,  0,0 hi,  0,1 si,  0,0 st
KiB Mem:   2058752 total,  1970636 used,    88116 free,    48248 buffers
KiB Swap:  4200992 total,     2596 used,  4198396 free.  1205316 cached Mem

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND
17638 marc      20   0 2928228  96636  63516 R 103,7  4,7 661:16.57 kwin


Notice the amount of accumulated CPU time. The screensaver is configured to
just show the blank screen, so it really shouldn't affect performance.
#745875#10
Date:
2014-04-26 09:52:45 UTC
From:
To:
¡Hola Marc!

El 2014-04-26 a las 10:19 +0200, Marc Coll escribió:

Mmh, interesting, I have seen a similar  behavior in my desktop (unstable with
kde-sc 4.12.4) but with kscreenlocker_g, which is closer to the bug reported
in the upstream bug tracker:
https://bugs.kde.org/show_bug.cgi?id=316348
but I can't reproduce it in my notebook (jessie with kde-sc 4.12.3).

I guess I'll try to narrow it down once I'm back home.
#745875#15
Date:
2014-04-26 09:52:45 UTC
From:
To:
¡Hola Marc!

El 2014-04-26 a las 10:19 +0200, Marc Coll escribió:

Mmh, interesting, I have seen a similar  behavior in my desktop (unstable with
kde-sc 4.12.4) but with kscreenlocker_g, which is closer to the bug reported
in the upstream bug tracker:
https://bugs.kde.org/show_bug.cgi?id=316348
but I can't reproduce it in my notebook (jessie with kde-sc 4.12.3).

I guess I'll try to narrow it down once I'm back home.
#745875#20
Date:
2014-06-28 08:38:27 UTC
From:
To:
Hello. I recently discovered that the screen lock under control panel's
"Screen and Monitor" section was enabled, and after I disabled it my CPU
consumption is back to normal. I guess the scren lock feature is somehow
related to this bug.
#745875#25
Date:
2014-06-28 08:38:27 UTC
From:
To:
Hello. I recently discovered that the screen lock under control panel's
"Screen and Monitor" section was enabled, and after I disabled it my CPU
consumption is back to normal. I guess the scren lock feature is somehow
related to this bug.