Xfwm 4.14 Compositor Troubleshooting Guide

ToZ · 2019-08-16 13:03:50

There have been numerous reported issues with the 4.14 release of xfwm related to transparency issues, compositing problems and blank screens. This post will provide some troubleshooting information to get the issue resolved.

There have been significant changes in the vblank code between 4.12 and 4.14 to help address and hopefully solve the screen tearing issues. xfwm4 now supports 3 vblank modes:

glx or auto - this is the default. Anecdotally, this seems to work well with intel cards and some nvidia/ati cards
xpresent - uses the xpresent libraries. Anecdotally, this seems to work well with newer ati/amd cards
off - this disables the vblank code. Anecdotally, this seems to work well with nvidia cards

To test which vblank mode works best for your system, simply restart xfwm and specify as a parameter which vblank mode to use:

xfwm4 --vblank=MODE --replace

...where "MODE" is one of: auto, glx , xpresent , or off.

If this fixes your problem, you can make it permanent via a vblank_mode setting:

xfconf-query -c xfwm4 -p /general/vblank_mode -t string -s "MODE" --create

...where "MODE" is one of: "auto", "glx", "xpresent", "off".

Note: if nothing is specified, glx is used.

Last edited by ToZ (2021-01-09 19:05:41)

sushi · 2019-10-14 06:42:36

Hi ToZ,

Thanks for this guide !

Here I have a fourth mode > "auto" . Is there any command to know which mode is use by "auto" ?

ToZ · 2019-10-14 11:33:47

Yes, you are right. "auto" is also valid and it uses the glx backend by default. I'll update my post.

Thanks.

sushi · 2019-10-14 12:25:45

My pleasure.

Thanks.

Racer-X · 2020-01-21 21:59:06

Changing vblank_mode from "auto" to "xpresent" resolved an issue for me. I as experiencing very high CPU loads only when I plugged an external monitor into the VGA port on my netbook and used it as a second monitor. Switching from "auto" to "xpresent" resolved the CPU overload.

My configuration:

$ sudo inxi -G
Graphics:  Device-1: Intel Mobile 945GSE Express Integrated Graphics driver: i915 v: kernel 
           Display: server: X.Org 1.20.5 driver: intel unloaded: fbdev,modesetting,vesa 
           resolution: 1024x600~60Hz, 1400x1050~60Hz 
           OpenGL: renderer: Mesa DRI Intel 945GME x86/MMX/SSE2 v: 1.4 Mesa 19.2.1

ibob · 2020-03-09 15:02:05

Ran into a performance problem when upgrading from 18.04 to 19.10: high CPU for Xorg when doing GUI related actions to the point that mouse was freezing. Example, switching workspaces took ~1sec. The problem was resolved with the suggested configuration change.

$ sudo inxi -G
Graphics:
  Device-1: Intel Haswell-ULT Integrated Graphics driver: i915 v: kernel 
  Display: server: X.Org 1.20.5 driver: modesetting unloaded: fbdev,vesa 
  resolution: 1920x1080~60Hz 
  OpenGL: renderer: Mesa DRI Intel Haswell Mobile v: 4.5 Mesa 19.2.8

sgx45edaz4 · 2020-04-02 20:43:28

Hi,

Not sure if this is the correct place to post this but if I run

xfwm4 --vblank=off --replace

to test with vblank_mode off, everything seems fine. However, if I make the change permanent by running

xfconf-query -c xfwm4 -p /general/vblank_mode -t string -s "off" --create

or

xfconf-query -c xfwm4 -p /general/vblank_mode -s off

when I restart and login, I have all black screens and I have to manually set it back to auto and reboot to fix it. My whole thinking in turning off vblank_mode in the first place was to disable the compositor's vsync because I am using Force Full Composition Pipeline in my Nvidia settings. My understanding is that having both FFCP and the compositor's vsync running is redundant and can cause extra lag, choppiness, etc. And, to my knowledge, vblank_mode is xfwm's implementation of vsync? However, I'm not understanding how simply disabling vblank_mode can cause the entire compositor to malfunction.

For reference, I am running 3 monitors and have an Nvidia GTX 770 card. I am also running a fresh install of XFCE 4.14 on Arch Linux. My config is below:

Graphics:  Device-1: NVIDIA GK104 [GeForce GTX 770] driver: nvidia v: 440.64 
           Display: x11 server: X.Org 1.20.8 driver: nvidia unloaded: modesetting 
           resolution: 1920x1080~60Hz, 1920x1080~60Hz, 1920x1080~60Hz 
           OpenGL: renderer: GeForce GTX 770/PCIe/SSE2 v: 4.6.0 NVIDIA 440.64

Last edited by sgx45edaz4 (2020-04-02 21:21:23)

ToZ · 2020-04-02 21:40:33

Hello and welcome.

I would suggest that you create a bug report against the xfwm4 product to bring it to the developer's attention. He may be best to advise.

jbierkens · 2020-04-24 15:33:35

Thanks, this is very helpful, same applies to me.

Setting --vblank=off makes the window manager perform much better.

Seems like a bug to me, so I filed a bug report here.
https://bugzilla.xfce.org/show_bug.cgi?id=16753

Signy · 2020-10-25 08:47:39

I had troubles with compositor too and it seems to me that "glx" and "auto" is not the same.
I use panning mode:

xrandr --output DVI-D-0 --mode 1920x1080 --fb 2580x1080 --panning 2580x1080

and when I switched copositor on, my screen was broken:

the screen was divided into rows with height approx. 100px,
the first row was OK, every other row was moved approx. 100px to the right (relatively to the previous row).

After testing it turned out that for me are possible modes: glx or off. Modes auto or xpresent are broken.

My system is Xubuntu 20.04 on AMD Ryzen 5 2400G.
But it is not clean installation - the system started maybe as Xubuntu 14.04 and was upgraded during years. Originally it was installed on an Intel quadcore with its internal graphics. I changed processor+graphics to AMD Ryzen 5 2400G (while running Xubuntu 18.04) couple years ago - so there might remain an old settings from previous installation on Intel processor.

$ sudo inxi -G
Graphics:
  Device-1: AMD Raven Ridge [Radeon Vega Series / Radeon Vega Mobile Series] 
  driver: amdgpu v: kernel 
  Display: server: X.Org 1.20.8 driver: amdgpu,ati 
  unloaded: fbdev,modesetting,vesa resolution: 1920x1080~60Hz 
  OpenGL: renderer: AMD RAVEN (DRM 3.35.0 5.4.45-050445-generic LLVM 10.0.0) 
  v: 4.6 Mesa 20.0.8

I want to thank to ToZ for this forum, it helped me a lot and now I can use compositor...

Last edited by Signy (2020-10-25 08:48:31)

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#1 2019-08-16 13:03:50

Xfwm 4.14 Compositor Troubleshooting Guide

#2 2019-10-14 06:42:36

Re: Xfwm 4.14 Compositor Troubleshooting Guide

#3 2019-10-14 11:33:47

Re: Xfwm 4.14 Compositor Troubleshooting Guide

#4 2019-10-14 12:25:45

Re: Xfwm 4.14 Compositor Troubleshooting Guide

#5 2020-01-21 21:59:06

Re: Xfwm 4.14 Compositor Troubleshooting Guide

#6 2020-03-09 15:02:05

Re: Xfwm 4.14 Compositor Troubleshooting Guide

#7 2020-04-02 20:43:28

Re: Xfwm 4.14 Compositor Troubleshooting Guide

#8 2020-04-02 21:40:33

Re: Xfwm 4.14 Compositor Troubleshooting Guide

#9 2020-04-24 15:33:35

Re: Xfwm 4.14 Compositor Troubleshooting Guide

#10 2020-10-25 08:47:39

Re: Xfwm 4.14 Compositor Troubleshooting Guide

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