[Debian-on-mobile-maintainers] Bug#1073294: plasma-settings uses excessive CPU time when doing nothing

[Russell Coker]

Package: plasma-settings
Version: 23.01.0-1+b1
Severity: normal

             19.6 ms/s      39.2        Process        [PID 36735] /usr/bin/plasma-settings -m kcm_mobile_wifi

Powertop givesthe above output for plasma-settings, 39.2 events per second.

Strace shows the following as most of the system calls it performs.  Could it
have a delay longer than 15ms?

ppoll([{fd=4, events=POLLIN}, {fd=11, events=POLLIN}], 2, {tv_sec=0, tv_nsec=14000000}, NULL, 0) = 0 (Timeout)
ppoll([{fd=4, events=POLLIN}, {fd=11, events=POLLIN}], 2, {tv_sec=0, tv_nsec=14000000}, NULL, 0) = 0 (Timeout)
ppoll([{fd=4, events=POLLIN}, {fd=11, events=POLLIN}], 2, {tv_sec=0, tv_nsec=15000000}, NULL, 0) = 0 (Timeout)
ppoll([{fd=4, events=POLLIN}, {fd=11, events=POLLIN}], 2, {tv_sec=0, tv_nsec=15000000}, NULL, 0) = 0 (Timeout)
ppoll([{fd=4, events=POLLIN}, {fd=11, events=POLLIN}], 2, {tv_sec=0, tv_nsec=14000000}, NULL, 0) = 0 (Timeout)
ppoll([{fd=4, events=POLLIN}, {fd=11, events=POLLIN}], 2, {tv_sec=0, tv_nsec=14000000}, NULL, 0) = 0 (Timeout)
ppoll([{fd=4, events=POLLIN}, {fd=11, events=POLLIN}], 2, {tv_sec=0, tv_nsec=15000000}, NULL, 0) = 0 (Timeout)
ppoll([{fd=4, events=POLLIN}, {fd=11, events=POLLIN}], 2, {tv_sec=0, tv_nsec=14000000}, NULL, 0) = 0 (Timeout)
ppoll([{fd=4, events=POLLIN}, {fd=11, events=POLLIN}], 2, {tv_sec=0, tv_nsec=14000000}, NULL, 0) = 0 (Timeout)
ppoll([{fd=4, events=POLLIN}, {fd=11, events=POLLIN}], 2, {tv_sec=0, tv_nsec=15000000}, NULL, 0) = 0 (Timeout)
ppoll([{fd=4, events=POLLIN}, {fd=11, events=POLLIN}], 2, {tv_sec=0, tv_nsec=14000000}, NULL, 0) = 0 (Timeout)


Below are 2 of the other lines from powertop.  This might be a more general
plasma-mobile bug.  But with the screen locked it's more obvious that
plasma-settings shouldn't take much CPU time than it is for the screenlocker.

             28.0 ms/s      50.7        Process        [PID 1887] /usr/bin/plasmashell --no-respawn
             23.6 ms/s      13.1        Process        [PID 49789] /lib/aarch64-linux-gnu/libexec/kscreenlocker_greet --immediateLock --graceTime 5000 --ksldfd 114


-- System Information:
Debian Release: trixie/sid
Architecture: arm64 (aarch64)

Kernel: Linux 6.1-rockchip (SMP w/6 CPU threads; PREEMPT)
Kernel taint flags: TAINT_CRAP, TAINT_UNSIGNED_MODULE
Locale: LANG=en_AU.UTF-8, LC_CTYPE=en_AU.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /usr/bin/dash
Init: unable to detect

Versions of packages plasma-settings depends on:
ii  kpackagetool5                                       5.115.0-2
ii  libc6                                               2.38-13
ii  libglib2.0-0t64                                     2.80.3-1
ii  libkf5configcore5                                   5.115.0-2
ii  libkf5coreaddons5                                   5.115.0-2
ii  libkf5dbusaddons5                                   5.115.0-2
ii  libkf5i18n5                                         5.115.1-2+b1
ii  libkf5modemmanagerqt6                               5.115.0-2
ii  libkf5networkmanagerqt6                             5.115.0-2
ii  libkf5package5                                      5.115.0-2
ii  libkf5quickaddons5                                  5.115.0-3
ii  libkf5solid5                                        5.115.0-2
ii  libqt5core5t64                                      5.15.13+dfsg-2
ii  libqt5dbus5t64                                      5.15.13+dfsg-2
ii  libqt5gui5t64                                       5.15.13+dfsg-2
ii  libqt5qml5                                          5.15.13+dfsg-2
ii  libqt5widgets5t64                                   5.15.13+dfsg-2
ii  libqt5xml5t64                                       5.15.13+dfsg-2
ii  libstdc++6                                          14.1.0-1
ii  plasma-framework                                    5.115.0-2
ii  qml-module-org-kde-kcm                              5.115.0-3
ii  qml-module-org-kde-kirigami-addons-labs-mobileform  0.11.0-2
ii  qml-module-org-kde-kirigami2                        5.115.0-2+b1

plasma-settings recommends no packages.

Versions of packages plasma-settings suggests:
pn  kaccounts-integration  <none>
pn  kaccounts-providers    <none>

-- debconf-show failed