knotify4 consumes many CPU cycles if kde sound system is used for notifications

[jhoechtl]

Knotify consumes upto 3% of my CPU when idle, unless I disable "Use KDE sound system" in System settings / Application and System notifications / Tab "Player Settings", Log out and Log on again.

A real battery killer .. no need for me to hold my breath for GPU sleep

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: kdebase-runtime 4:4.7.4-0ubuntu0.1
ProcVersionSignature: Ubuntu 3.0.0-16.29-generic 3.0.20
Uname: Linux 3.0.0-16-generic x86_64
ApportVersion: 1.23-0ubuntu4
Architecture: amd64
Date: Tue Mar 6 22:02:15 2012
InstallationMedia: Kubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111011)
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=en_US:en
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: kde-runtime
UpgradeStatus: No upgrade log present (probably fresh install)

[jhoechtl (johann-hoechtl)]

User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:10.0.2) Gecko/20100101 Firefox/10.0.2
Build Identifier:

knotify4 when using phonon gstreamer backend consumes way to much CPU cycles.

Reproducible: Always

Steps to Reproduce:
0. KDE 4.7.4 and upwards (possibly earlier versions)
1.System settings / Application and System Notifications: Player Settings: Assure, that "Use the KDE sound system" is ticked.
2.System settings / Multimedia / Phonon / Backend: Assure that GStreamer is the Phonon backend (here version 4.5.1.)
3.Open Terminal, run "top", let the system go idle. knotify4 is on top (using 2% CPU, speed dependent, of course)

3. Disabling sound notifications to "No audio output" (log out after setting) or using vlc as the phonon backend makes CPU usage go away.

Calling it a major bug as it consumes loads of CPU cycels for no good, causing thermal heat, dying laptop batteries and makes upcoming RC6 GPU sleep rather pointless for KDE gstreamer default installations.

[jhoechtl (johann-hoechtl)]

Corresponding to bugs.kde.org id 295462:
https://bugs.kde.org/show_bug.cgi?id=295462

[Myriam Schweingruber (myriam)]

The problem doesn't appear for me here, using the phonon-backend-gstreamer 4.6. Could you please upgrade and see if that still happens for you?

Using Kubuntu 12.04 beta1, KDE 4.8.1, Qt 4.8

[jhoechtl (johann-hoechtl)]

I will have to wait until Kubuntu 12.04 is out. Or is there a way to test gstreamer backend V 4.6 on Kubuntu 11.10?

[Myriam Schweingruber (myriam)]

(In reply to comment #2)
> I will have to wait until Kubuntu 12.04 is out. Or is there a way to test
> gstreamer backend V 4.6 on Kubuntu 11.10?

Keep an eye on https://launchpad.net/~kubuntu-ppa/+archive/backports, they should backport it these days.

[jhoechtl (johann-hoechtl)]

This bug does not persist any more with KDE 4.8.2 (as of Kubuntu 12.04)

[Myriam Schweingruber (myriam)]

Thank you for the feedback, closing then.