Bug 427471 - Dolphin using up 100% CPU
Summary: Dolphin using up 100% CPU
Status: REPORTED
Alias: None
Product: dolphin
Classification: Applications
Component: general (show other bugs)
Version: 20.08.1
Platform: Arch Linux Linux
: NOR major
Target Milestone: ---
Assignee: Dolphin Bug Assignee
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2020-10-09 01:58 UTC by roachh@protonmail.com
Modified: 2022-05-05 18:37 UTC (History)
6 users (show)

See Also:
Latest Commit:
Version Fixed In:
Sentry Crash Report:


Attachments
Dolphin useing up 98% of my CPU core (specifically, it alternates between CPUs 3, 5, and 7) (6.55 KB, image/png)
2020-10-09 01:58 UTC, roachh@protonmail.com
Details

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Description roachh@protonmail.com 2020-10-09 01:58:24 UTC
Created attachment 132228 [details]
Dolphin useing up 98% of my CPU core (specifically, it alternates between CPUs 3, 5, and 7)

SUMMARY
While dolphin is open, nearly 100% of a CPU core is used, if not even more. This happens even on empty folders.

STEPS TO REPRODUCE
1. Open dolphin
2. Open ksysguard, or any system monitor, and sort by CPU usage
3. Observe

OBSERVED RESULT
Dolphin is at the top, with at least 95% CPU usage (assuming you are NOT dividing by total amount of cores), often 98-100%

EXPECTED RESULT
Dolphin should use very little CPU.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: 5.8.14-arch1-1 kernel, Plasma 5.19.5-1
(available in About System)
KDE Plasma Version: 5.19.5
KDE Frameworks Version: 5.74.0
Qt Version: 5.15.1

ADDITIONAL INFORMATION
Reproducable as early as dolphin 20.07.80, 5.8.2 kernel
It stays like this the whole time the app is open. Never goes down, never goes up.
Comment 1 Elvis Angelaccio 2021-03-21 15:43:01 UTC
Is this still reproducible?

If yes, please get a stacktrace after the CPU usage goes up.
You can run "gdb dolphin" from konsole, then press CTRL+C and type "bt".
Comment 2 roachh@protonmail.com 2021-03-21 16:01:10 UTC
(In reply to Elvis Angelaccio from comment #1)
> Is this still reproducible?
>
> If yes, please get a stacktrace after the CPU usage goes up.
> You can run "gdb dolphin" from konsole, then press CTRL+C and type "bt".

Yes. In fact it actually seems to use even more, as my CPU usage is going from 0% to 18% when I initially open it. I haven't tested it on X recently (currently on sway), so when I get home, I'll try with i3 or something, as it could be Wayland tarding (wouldn't be the first time a KDE application sucks/doesn't work properly with Wayland...)

Anyways, when I'm home I'll test on X. And can I instead use `strace` as it can output to a file? I can just Ctrl-C it once the CPU usage goes up and it'll have the stacktrace up to that point.
Comment 3 roachh@protonmail.com 2021-03-22 13:21:19 UTC
okay, so its using up anywhere from 18-24% overall CPU (2 threads entirely). here's the backtrace from gdb:

> #0  0x00007ffff7dc537f in poll () at /usr/lib/libc.so.6
> #1  0x00007ffff3cdddef in  () at /usr/lib/libglib-2.0.so.0
> #2  0x00007ffff3c856d1 in g_main_context_iteration () at /usr/lib/libglib-2.0.so.0
> #3  0x00007ffff5d60681 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
> #4  0x00007ffff5d0639c in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
> #5  0x00007ffff5d0e834 in QCoreApplication::exec() () at /usr/lib/libQt5Core.so.5
> #6  0x00007ffff7ee5f43 in kdemain () at /usr/lib/libkdeinit5_dolphin.so
> #7  0x00007ffff7cf8b25 in __libc_start_main () at /usr/lib/libc.so.6
> #8  0x000055555555505e in _start ()
Comment 4 Bug Janitor Service 2021-04-06 04:33:27 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 5 Bug Janitor Service 2021-04-21 04:33:21 UTC
This bug has been in NEEDSINFO status with no change for at least
30 days. The bug is now 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

Thank you for helping us make KDE software even better for everyone!
Comment 6 Paschalis Veskos 2022-01-02 23:36:20 UTC
I can confirm this keeps happening to my setup as well:
Dolphin Version 21.12.0, Plasma 5.23.4, KDE Frameworks 5.88.0, Qt 5.15.2 on X11
Linux 5.15.6-1-default
openSUSE Tumbleweed 20211211

The stacktrace from gdb when this happens is:

(gdb) bt
#0  0x00007f31322f6b6f in __GI___poll (fds=0x55d1ce98b500, nfds=8, timeout=0) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007f31304500be in g_main_context_poll (priority=<optimized out>, n_fds=8, fds=0x55d1ce98b500, timeout=<optimized out>, context=0x7f3128005000) at ../glib/gmain.c:4478
#2  g_main_context_iterate (context=context@entry=0x7f3128005000, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ../glib/gmain.c:4170
#3  0x00007f31304501df in g_main_context_iteration (context=0x7f3128005000, may_block=1) at ../glib/gmain.c:4240
#4  0x00007f3132952ed4 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5
#5  0x00007f31328fa3fb in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5
#6  0x00007f31329026e0 in QCoreApplication::exec() () from /lib64/libQt5Core.so.5
#7  0x000055d1cdad0952 in main (argc=<optimized out>, argv=<optimized out>) at /usr/src/debug/dolphin-21.12.0-1.1.x86_64/src/main.cpp:212
Comment 7 Emanuele Spirito 2022-05-05 18:37:09 UTC
Maybe a duplicate of kde bug 411349?
https://bugs.kde.org/show_bug.cgi?id=411349