Arch Linux

Koren

Member

Registered: 2018-10-01

Posts: 10

Plasma+Intel X11 Weird lag / performance problem on 2 computers

Hello,

I run Arch Linux on 2 identical computers, running with Intel graphics adapters.
Since a few weeks, i notice a very strange behaviour:

Whenever I start an application in Plasma (eigher via Konsole or via graphical UI), I have a 2s freeze and then the application starts fine.
During that short freeze, the mouse cursor cannot be moved and the whole machine is completely unresponsive.

This ONLY happens, when I have more than 1 screen connected to the computers and the compositor is active. When I either a) only use 1 screen
or b) disable compositing, that freeze does not happen.

In journalctl and dmesg, there is NO message at all in this moments. No hint on what the problem could be.

Hardware/System:

- Arch Linux updated to the latest packages (by 2018-10-01)
- Intel(R) Core(TM) i7-6600
- Intel HD Graphics 520
- 2 external screens are connected via HDMI/DP

Does anyone have a clue ? Or some hint how to get more information on what's going on here ?
Some Update in the last 2 weeks brought that problem. But I can't tell witch one it was.

best regards,

Koren

LordChaos73

Member

From: .nl

Registered: 2008-11-11

Posts: 183

Re: Plasma+Intel X11 Weird lag / performance problem on 2 computers

Are you using Wayland or X.org?

Sorry, should have read the topic more carefully.

No clues in /var.log/Xorg.0.log either?

Last edited by LordChaos73 (2018-10-01 17:53:38)

Koren

Member

Registered: 2018-10-01

Posts: 10

Re: Plasma+Intel X11 Weird lag / performance problem on 2 computers

Hi,

In the /var/log/Xorg.0.log I recieve this message, every time, the Freeze happens:

[   896.322] (II) event20 - Logitech USB Gaming Mouse: SYN_DROPPED event - some input events have been lost.

I already tried 3 different Mouses, but no change (except the Input device name ...):

[  1408.998] (II) event20 - Logitech USB Optical Mouse: SYN_DROPPED event - some input events have been lost.
[  1450.192] (II) event20 - Logitech USB Optical Mouse: SYN_DROPPED event - some input events have been lost.

arojas

Developer

From: Spain

Registered: 2011-10-09

Posts: 2,098

Re: Plasma+Intel X11 Weird lag / performance problem on 2 computers

It's a Qt issue. Fix should be available soon.

https://bugreports.qt.io/browse/QTBUG-70760