130228 - Slow scrolling with very big background image

Status: RESOLVED DUPLICATE of bug 130027

(Core Graveyard :: GFX, defect)

Description

[Andrea Aime]

From Bugzilla Helper:
User-Agent: Mozilla/5.0 (Windows; U; WinNT4.0; en-US; rv:0.9.9+) Gecko/20020310
BuildID:    2002031008

Browsing a demo CD I found lots of pages with
a big (non fixed) background, something like
a 1500 x 6000 gif image. IE 5 and Konqueror
handles this without a glitch, and even Mozilla
on Linux scrolls with decent performance (althought
a bit slower than konqueror) but Mozilla on my
NT box is just plain slow, scrolling happens with 100%
CPU utilization and it's a really painful experience

Reproducible: Always
Steps to Reproduce:
1. Use Mozilla under NT 4.0
2. Open the attached page
3. Scroll

Actual Results:  Painfully slow scrolling

Expected Results:  Smooth scrolling like in every other page

Comment 1

[Andrea Aime]

Attachment: Exaple page that shows the slow scrolling behaviour

Comment 2

[Adam Hauner]

Adding URL on page with same problem. 

Comment 3

[Andrea Aime]

Yes, I can confirm the slow scrolling on
http://www.digitalriver.com/dr/v2/ec_MAIN.Entry10?
V1=338456&PN=1&SP=10023&xid=21763&DSP=&CUR=840&PGRP=0&CACHE_ID=52704
... but the page displays correctly, I don't see the problem 
mentioned in bug 129987...

Comment 4

[Adam Hauner]

Oops, I posted bad URL. Page from bug 129987 has same problem with slow
scrolling, black text on black background (bug 129987) is of course irelevant to
this bug. I hope, that clickable URL is better for understanding problem of bug
than attached zipfile.

Comment 5

[Boris Zbarsky [:bzbarsky]]

actually, the best thing is an uncompressed testcase attached to the bug. 
clickable urls tend to change and not exhibit bugs anymore...

Comment 6

[Daniel Steinberger]

** is there a reason, this one is still UNCONFIRMED? ** (since I can confirm on
2002031403/WinXP)

i can't believe the heavy regression this bug causes. in the 0.9.9 branch,
things are quite smooth. but with 2002031403 every second page i visit (well,
almost) gets awfully slow. how could this occur? wasn't the 0.9.9 -> 1.0 checkin
stuff restricted to 'mainly bugfixes, bugfixes and.. uhm.. more bugfixes' as
well as 'polish and perf'-work ??
this one is _heavy_ regression (adding keyword) and IMHO would deserve 'blocker'
status, or does anyone want to tell me, < 0.5fps on scolling (eye measurement)
such a 'simple' page (on an athlon 1GHz with 1GB of RAM) would be OK for Mozilla
v1.0 (or even a nightly trunk build), when it wasn'T present in 0.9.9?

bz: i found this image stuff to cause my page reflow slowness, too.

Comment 7

[Adam Hauner]

Confirming regarding user's comments

Comment 8

[WD]

See also:

http://www.devx.com
http://www.proactiv.com

Comment 9

[Jacek Chmiel]

I confirm this to be a serious bug.
Take a look at http://www.devx.com.
Scrolling is unacceptable slow (Windows XP, GeForce2Ti, 1GHz celeron, 512MB RAM).
It was ok with Mozilla 0.9.9 - with post-0.9.9 builds it's too slow making
browser practically unusable with some pages. Severity should be increased to
MAJOR in my opinion. I cannot imagine version 1.0 with this bug existing.

Comment 10

[Adam Hauner]

Nominating for M1.

Comment 11

[Kevin McCluskey (gone)]

patblt call on WINNT with a large image is very slow.

*** This bug has been marked as a duplicate of 130027 ***