424529 - Performance Regression on Javascript controlled Page-Scroll from Firefox 1.06 Linux to Firefox 2.0.12 Linux

Status: RESOLVED WONTFIX

(Core Graveyard :: GFX, defect)

Description

[Tobias Caspers]

User-Agent:       Mozilla/5.0 (X11; U; Linux i686; de; rv:1.8.1.12) Gecko/20080201 Firefox/2.0.0.12
Build Identifier: Mozilla/5.0 (X11; U; Linux i686; de; rv:1.8.1.12) Gecko/20080201 Firefox/2.0.0.12

I worte a Greasemonkey Script which included a kind of automatic Page-Scroll controlled by Javascript.
(Inspired by a demo of the jquery javascript framework, see below...)

Using that Script on both Windows and Linux, I discovered a significant worse scrolling performance on Linux: On Linux, it scrolls much slower and jerkier than on windows.

I made a quick and dirty demonstration page you can use without Greasemonkey:
http://home.arcor.de/bazonbloch/scrolltest/whyisscrollingonlinuxslowerthanonwindows.htm

(Another page showing the same effect, but without measuring, is a demopage of the jquery javascript framework: http://flesler.webs.com/jQuery.ScrollTo/ )

Use the arrows to trigger autoscroll there, the time it takes is measured automatically.

Showing that on Mozillazine Forums http://forums.mozillazine.org/viewtopic.php?t=640539 , it was discovered, that even on different Firefox Versions for windows this page showed different performance.

Unfortunately, newer builds are slower:

On my computer:
Mozilla/5.0 (Windows; U; Windows NT 5.1; de; rv:1.8.1.12) Gecko/20080201 Firefox/2.0.0.12 scrolls fast and smooth:
about 1220ms
Mozilla/5.0 (X11; U; Linux i686; de-DE; rv:1.7.10) Gecko/20050911 Firefox/1.0.6 (Debian package 1.0.6-5) scrolls slow and smooth:
about 2000ms
Mozilla/5.0 (X11; U; Linux i686; de; rv:1.8.1.12) Gecko/20080201 Firefox/2.0.0.12 scrolls slow and jerky:
about 3000ms.

On the Computer of Mozillazine User "Cusser"
2.0.0.12 on Windows XP is smooth and fast: about 1200ms
3.0b5pre on Windows XP is jerky and slow: about 2300ms


Reproducible: Always

Steps to Reproduce:
1. Go to http://home.arcor.de/bazonbloch/scrolltest/whyisscrollingonlinuxslowerthanonwindows.htm with different versions of Firefox.
2. Hit the Arrows and notice scrolltime and smoothness of scrolling.

Actual Results:  
Firefox 2.0.12 Windows: 1200ms, smooth
Firefox 1.06 Linux: 1800ms, smooth
Firefox 3.0b5pre Windows: 2300ms, jerky
Firefox 2.0.12 Linux: 3000ms, jerky

Expected Results:  
Newer Builds should not be slower than older builds on the same hardware,
Linux Builds should not be so much slower than Windows Builds on the same hardware.

This test was performed in safe-mode and with extensions enabled, that made no difference.

Used Linux Systems were Ubuntu 7.10 and Knoppix 4.0.

Thread about that in Mozillazine Forums:
http://forums.mozillazine.org/viewtopic.php?t=640539

Comment 1

[Tobias Caspers]

Changed OS to Linux only according to http://forums.mozillazine.org/viewtopic.php?p=3306512#3306512

So in this Bug, only the performance regression from 1.06 Linux to 2.0.12 Linux should be regarded, the regresseion from 2.0.12 Windows to 3.0b5pre wil be filed in another bug

Comment 2

[Tobias Caspers]

Now I testesd it with Minefield for Linux Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9pre) Gecko/2008032804 Minefield/3.0pre and it's even worse:

Scrolling on the testpage takes about 8300ms!
(remember: actual Firefox 2.0.12 Windows on same hardware: 1200ms)

Comment 3

[Tobias Caspers]

Just to let you know:
New Tests on same hardware:
Mozilla/5.0 (X11; U; Linux i686; de; rv:1.9.0.10) Gecko/2009042513 Ubuntu/8.04 (hardy) Firefox/3.0.10:
2600ms

Mozilla/5.0 (X11; U; Linux i686; de; rv:1.9.1b4) Gecko/20090423 Firefox/3.5b4
2300ms

So at least it got better again... :-)
(anyway it's still faster on windows)

Comment 4

[Gordon P. Hemsley [:GPHemsley]]

This bug has been buried in the graveyard and has not been updated in over 5 years. It is probably safe to assume that it will never be fixed, so resolving as WONTFIX.

[Mass-change filter: graveyard-wontfix-2014-09-24]