Bug 92492 - [SNA] Input lag on QT based applications
Summary: [SNA] Input lag on QT based applications
Status: NEW
Alias: None
Product: xorg
Classification: Unclassified
Component: Driver/intel (show other bugs)
Version: unspecified
Hardware: x86-64 (AMD64) Linux (All)
: medium normal
Assignee: Chris Wilson
QA Contact: Intel GFX Bugs mailing list
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2015-10-16 10:00 UTC by Iván Perdomo
Modified: 2015-10-16 11:16 UTC (History)
0 users

See Also:
i915 platform:
i915 features:


Attachments
Xorg.0.log (24.45 KB, text/plain)
2015-10-16 10:00 UTC, Iván Perdomo
no flags Details

Note You need to log in before you can comment on or make changes to this bug.
Description Iván Perdomo 2015-10-16 10:00:11 UTC
Created attachment 118913 [details]
Xorg.0.log

Thinkpad X230
Kernel: 4.2.3-1-ARCH
Distribution: Arch Linux
Package version: xf86-video-intel 1:2.99.917+478+gdf72bc5-2


There is a lag when using keyboard and mouse on QT based applications (e.g. Skype, VirtualBox) but not in the rest of the system.

The lag is "solved" when using UXA acceleration - 
http://whitecape.org/stuff/30-uxa.conf
Comment 1 Chris Wilson 2015-10-16 10:23:18 UTC
Based on previous investigations, my immediate suspicion is that the Qt applications are effectively running unthrottled and build up a long render queue.

Looking at intel-gpu-top or even intel-gpu-overlay should show the GPU maxed out (or nearly), and netstat --unix should (if I am right about the backlog being large enough) show pending bytes from the client to X.
Comment 2 Iván Perdomo 2015-10-16 11:16:56 UTC
Hi,

How can I produce a log of the GPU usage so i can attach it to the bug report?

Thanks for the support


Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.