Bug 300901

Summary:	kwin drags when starting up
Product:	[Plasma] kwin	Reporter:	Saurabh Asthana <faplap>
Component:	general	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED WORKSFORME
Severity:	normal	Flags:	mgraesslin: Intel+
Priority:	NOR
Version:	unspecified
Target Milestone:	---
Platform:	Ubuntu
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:
Attachments:	qdbus org.kde.kwin /Kwin supportInformation

Description Saurabh Asthana 2012-05-31 00:58:48 UTC

Whenever I login to KDE, kwin is extremely slow - opening the kickoff menu, spawning windows, switching between windows, all take up to tens of seconds.

However, I can fix this by opening Settings/Desktop Effects and selecting 'Advanced'. There I change the rendering engine from OpenGL to XRender - KDE pops up a confirmation dialog and I refuse, reverting back to openGL. Now everything works fine. No lag at all.

Reproducible: Always




I am using Oxygen decorations with openGL and desktop effects enabled. I have an onboard intel graphics chip from five years ago.

Comment 1 Martin Flöser 2012-05-31 06:37:48 UTC

try to disable OpenGL 2 shaders with such an old GPU

Comment 2 Thomas Lübking 2012-05-31 08:20:01 UTC

all lags seem related to active window changes
->also try another decoration (not aurorae themes, but eg. try "laptop")

if that helps: in "oxygen-settings" you can deactivate animations - does that help?

Comment 3 Thomas Lübking 2012-08-26 10:56:43 UTC

Is this still an issue (with 4.9)

In this case please provide the output of
qdbus org.kde.kwin /KWin supportInformtaion
while things are slow AND after improvements through the workaround

Comment 4 Saurabh Asthana 2012-09-08 02:32:12 UTC

Created attachment 73737 [details]
qdbus org.kde.kwin /Kwin supportInformation

Comment 5 Saurabh Asthana 2012-09-08 02:33:55 UTC

Not sure if it's still the same bug, but now my workaround no longer seems to cut the mustard, and OpenGL rendering is always slow. I've isolated it down to the blur effect (disabled in the above supportInformation log); disabling this seems to ease the problem.

Comment 6 Martin Flöser 2012-09-08 07:14:27 UTC

By default the Blur shader is disabled for your hardware, so that seems just fine. I would also recommend to disable the usage of OpenGL 2 shaders. Given that with default settings the problem does not exist, I dare to set to worksforme.

I just created a new bug 306436 to automatically use the OpenGL 1 backend for your hardware.

Comment 7 Saurabh Asthana 2012-09-08 20:59:43 UTC

I don't have a huge problem with that, but I'll point out that the Blur shader worked just fine in the past with this hardware, so it seems like the problem is not insurmountable. Just maybe not worth it.

Comment 8 Thomas Lübking 2012-09-08 21:20:20 UTC

ARB program bluring will be faster than GLSL blurring in that GPU.
Do not use GLSL or use kwin_gles

Also the intel driver from time to time simply lies about several capabilities.
Reduce the blur strength by hand - at some point it might suddenly be fast again.
Nevertheless, NOT using "OpenGL 2 shaders" is the sane option for that chip (blurring will still work as manymost other effects)