Bug 168441

Summary:	KNotify4 Uses Way too Much CPU Power
Product:	[Frameworks and Libraries] Phonon	Reporter:	John Doe <superechidna>
Component:	general	Assignee:	Matthias Kretz <kretz>
Status:	RESOLVED DUPLICATE
Severity:	normal	CC:	andresbajotierra, giggi1999, grundleborg, invisibunny, kde, kevin, me, MurzNN, shikamaru
Priority:	NOR
Version:	unspecified
Target Milestone:	---
Platform:	Ubuntu
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description John Doe 2008-08-05 18:36:49 UTC

Version:            (using KDE 4.1.0)
Installed from:    Ubuntu Packages
OS:                Linux

According to the System Monitor in Kubuntu running KDE 4.1 and the loud noise of the cooling my CPU, the process knotify4 is using about 49-50% of the CPU on my IBM Thinkcentre S50 (8183CVU), which has a 2.8 GHz Pentium IV CPU. In comparison, firefox uses 3%. I am not sure what knotify4 does, but I honestly doubt that it needs to use that much CPU power. It does not seem to be a completely essential process because after I killed it I have seen no bad side effects and my fan has quieted down considerably from the roar a few seconds ago. Now its gotten even quieter. FYI Renicing the process did not make it use less CPU, but killing it did.

Comment 1 Dario Andres 2009-01-06 15:44:22 UTC

Can you still reproduce this bug with a recent KDE (4.1.3 / 4.2beta2 / 4.2svn) ? Thanks :)

Comment 2 Michel Filipe 2009-01-09 13:15:47 UTC

Hi! This is happening with me. I'm using kde-4.1.3 with openSuse.

Always that I listen music with Amarok using phonon (with xine backend) my knotify uses much CPU power.

Comment 3 Olivier Goffart 2009-02-14 21:11:34 UTC

SVN commit 926199 by ogoffart:

Load the image lazily from the byte array,   we don't need it in mosts cases.

CCBUG: 168441



 M  +7 -12     knotify.cpp  
 M  +3 -4      knotify.h  
 M  +11 -1     knotifyconfig.cpp  
 M  +21 -2     knotifyconfig.h  
 M  +4 -4      notifybypopup.cpp  
 M  +1 -1      notifybytaskbar.cpp  


WebSVN link: http://websvn.kde.org/?view=rev&revision=926199

Comment 4 Rémy CLOUARD 2009-03-23 12:14:53 UTC

I confirm this.

For me it happened because I unplugged my audio usb headset, plugin it back solved the problem.

see following strace:
http://pastebin.mandriva.com/8568

it seems that knotify still tries to access the device though it is unavailable, and once it is knotify calms down.

Comment 5 Rick George 2009-04-05 17:51:59 UTC

I am in Gentoo using 4.2.1, and am having the same issue as described in comment 4.  My sound card died so I have to use USB speakers right now.  When they are on all is well.  When they are turned off and knotify tries to play a sound, such as when an email is received, CPU usage goes through the roof and I have to kill the process.

Comment 6 giggi1999 2009-04-20 19:55:15 UTC

I'm using Arch Linux with KDE 4.2.2 (x86_64)
And I've the same problem but knotify4 get all the cpu only after the 'suspend'.

Comment 7 Kevin Colyer 2009-04-28 22:32:29 UTC

I have this problem too on the new Jaunty with 4.2.2. I'm not running amarok but I think it might come from the popup notices. It seems to happen after I have been copying files around and then let the machine idle. Killing knotify4 solves the problem short term.

Comment 8 Flavio 2009-10-12 17:37:17 UTC

*** This bug has been confirmed by popular vote. ***

Comment 9 Mark Kretschmann 2009-11-09 08:21:43 UTC

This looks very much like a dupe of BUG 156215

Comment 10 Myriam Schweingruber 2009-12-12 00:05:42 UTC


*** This bug has been marked as a duplicate of bug 156215 ***

Comment 11 Murz 2010-01-31 12:07:29 UTC

Same issue on Kubuntu Karmic with amarok and KDE 4.3, and still here on KDE 4.4 RC2.
Killing knotify4 solves the problem short term.
At now, for example, Knotify uses every time 99-100% one of my 3 AMD processors every time, total is 64 hours of CPU usage:
$ ps u -p 29200
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
tat      29200  0.9  0.3 713364 13064 ?        SNl  Jan26  64:41 /usr/bin/knotify4