Bug 317087

Summary:	KDE 4.10 KMix PulseAudio Slow and Freezing
Product:	[Applications] kmix	Reporter:	Cygni X <cygnix>
Component:	general	Assignee:	Christian Esken <esken>
Status:	RESOLVED DUPLICATE
Severity:	normal	CC:	esken, lukas.zachy, malte.e
Priority:	NOR
Version:	4.3
Target Milestone:	---
Platform:	openSUSE
OS:	Linux
URL:	http://www.youtube.com/watch?v=QJtCC0FSPFs
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description Cygni X 2013-03-20 16:03:32 UTC

Since upgrading to KDE 4.10, KMix has been behaving abnormally where it slows down, eats CPU, and at times, freezes. When increasing/decreasing/muting the volume,  KMix becomes extremely slow and non-responsive. If it is killed and restarted, it usually works fine for a while, but after a reboot, the issue reappears.

Reproducible: Always

Steps to Reproduce:
1. KDE 4.10, KMix , and PulseAudio system
2. Use volume control
3.
Actual Results:  
KMix is slow and non-responsive with high CPU usage.

Expected Results:  
KMix should not lag or freeze.

If PulseAudio is disabled/removed, the issue seems to go away. It is specific to KDE 4.10. I have attached a video link demonstrating the problem. It was tested on openSUSE 12.2 and 12.3.

Comment 1 Colin Guthrie 2013-03-20 16:26:02 UTC

As far as I'm aware, there haven't been any PA specific changes that would cause this. Therefore the problem is most likely in generic code that deals with dynamic changes to the mixer elements and is only exposed by the PulseAudio backed as the most prolific user of these capabilities. Therefore assigning to the general component.

Comment 2 Cygni X 2013-03-20 16:57:53 UTC

(In reply to comment #1)
> As far as I'm aware, there haven't been any PA specific changes that would
> cause this. Therefore the problem is most likely in generic code that deals
> with dynamic changes to the mixer elements and is only exposed by the
> PulseAudio backed as the most prolific user of these capabilities. Therefore
> assigning to the general component.

That's fine. I only chose PulseAudio because the conflict appears with PA enabled as I explained in the initial report; if PA is removed, the issue is no longer there. This is not saying PA is the cause.

Comment 3 Malte Eggers 2013-04-15 07:23:10 UTC

A quick search came up with this:
http://qdosmsq.dunbar-it.co.uk/blog/2011/11/does-your-volume-control-freeze-on-kde/
So it doesn't seem to be a bug related to KDE 4.10, but rather to an upgrade from an earlier version to 4.10. The solution on the website worked for me so far, also across reboots.

Comment 4 Malte Eggers 2013-04-15 07:27:32 UTC

seems to be a duplicate of bug #314803

Comment 5 Cygni X 2013-04-17 15:03:07 UTC

(In reply to comment #3)
> A quick search came up with this:
> http://qdosmsq.dunbar-it.co.uk/blog/2011/11/does-your-volume-control-freeze-
> on-kde/
> So it doesn't seem to be a bug related to KDE 4.10, but rather to an upgrade
> from an earlier version to 4.10. The solution on the website worked for me
> so far, also across reboots.

As noted in the initial report, it first appeared after upgrading to KDE 4.10 on openSUSE 12.2, however, on a clean install of openSUSE 12.3 (which comes with KDE 4.10), the bug also exist.

Comment 6 Cygni X 2013-04-17 15:40:58 UTC

(In reply to comment #4)
> seems to be a duplicate of bug #314803

Yes, it's seems to be the same bug as it only appeared with KDE 4.10 as reported there as well.

Comment 7 Cygni X 2013-04-17 15:41:51 UTC


*** This bug has been marked as a duplicate of bug 314803 ***