Bug 501182 - Very slow trapezoid rasterization
Very slow trapezoid rasterization
Product: Fedora
Classification: Fedora
Component: xorg-x11-drv-intel (Show other bugs)
All Linux
low Severity medium
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Assigned To: Kristian Høgsberg
Fedora Extras Quality Assurance
Depends On:
  Show dependency treegraph
Reported: 2009-05-17 12:01 EDT by Clemens Eisserer
Modified: 2009-06-12 19:36 EDT (History)
2 users (show)

See Also:
Fixed In Version:
Doc Type: Bug Fix
Doc Text:
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Clone Of:
Last Closed: 2009-06-12 19:36:53 EDT
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RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

Attachments (Terms of Use)
sysprof profile of OOo moving simple chart arround (1.01 MB, text/plain)
2009-05-17 12:04 EDT, Clemens Eisserer
no flags Details
FireFox performance comparison of XAA, EXA and UXA (15.02 KB, application/octet-stream)
2009-05-18 15:32 EDT, Clemens Eisserer
no flags Details

External Trackers
Tracker ID Priority Status Summary Last Updated
FreeDesktop.org 21376 None None None Never

  None (edit)
Description Clemens Eisserer 2009-05-17 12:01:49 EDT
Description of problem:

All applications which render a lot of trapezoids are quite slow when using UXA+KMS. I guess this is caused by the fix for bug 490839.

Version-Release number of selected component (if applicable):
intel 2.7.0-4
xorg 1.6.1

How reproducible:
Always. Some applications suffer less, some a lot (OpenOffice 3.1, FireFox for some pages).

Steps to Reproduce:
1. Open an openoffice(3.1)-document 
1.2. Move e.g. a chart arround
2. Open a trapezoid-heavy page in firefox.
Actual results:
Very slow rendering of trapezoids, profilers show almost all time spent in pixman_rasterize_edges.
Because the amount of trapezoids is the same for EXA/XAA/UXA the only conclusion I can make is that memory access is uncached and therefor slowing that code down.

Expected results:
At least as fast as EXA

Additional info:

I reported this bug already upstream, however I am not sure its really their fault:
Comment 1 Clemens Eisserer 2009-05-17 12:04:14 EDT
Created attachment 344335 [details]
sysprof profile of OOo moving simple chart arround
Comment 2 Clemens Eisserer 2009-05-18 15:31:35 EDT
I did some firefox performance measurements using Trender.
XAA/EXA was on Fedora8 with intel-2.2.1
UXA was on Fedora 10 with KMS

The steady slowdown is concerning  :-/
Comment 3 Clemens Eisserer 2009-05-18 15:32:51 EDT
Created attachment 344509 [details]
FireFox performance comparison of XAA, EXA and UXA
Comment 4 Bug Zapper 2009-06-09 11:59:04 EDT
This bug appears to have been reported against 'rawhide' during the Fedora 11 development cycle.
Changing version to '11'.

More information and reason for this action is here:
Comment 5 Clemens Eisserer 2009-06-12 19:36:53 EDT
This is an intel-bug, caused by rendering trapezoid to pixmaps instead of system memory. Should be fixed in 2.8 (pre releases).

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