104250 - Performance problems when loading/drawing a page with huge tables and massive number of images

Status: RESOLVED WORKSFORME

(Core :: Layout: Images, Video, and HTML Frames, defect)

Description

[Russ LeBar]

From Bugzilla Helper:
User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)
BuildID:    2001091520

We have a web-site that auto-refreshes every 10 seconds that makes extensive 
use of tables, along the lines of grid layout. Might be 50x50 or larger and 
some cells also have tables within them. Most of these cells have JPEG images 
in them. Some may be rescaled via "size" tags (there is a "smaller size" 
version). For the curious, we use his page to monitor our VSAT gear, including 
drill down diagrams for each satelite. It is a perl/cgi script and Apache is 
the web server.

Reproducible: Always
Steps to Reproduce:
1. Run a performance monitoring tool such as top.

2. Make sure Cache is set to compare the page "Every time I view the page"

3. Point Mozilla to a web page with huge tables and a massive number of images 
(JPEGs in our case, but might do it for PNG or GIF as well) that auto-refreshes 
every 10 seconds.

4. Watch Mozilla suck up CPU cycles, e.g. 33-35% of the CPU and/or cry. :-)

Actual Results:  According to top I saw 33% to 35% CPU usage. 35% usage was 
during the refresh period. This was on a Sun Ultra-10 running Solaris 8 with 
Maintenance Upadate 5 applied plus more recent recommended patches.

Running under the KDE 2.1.1 (downloaded from Patriotsoft).

Expected Results:  Needs to perform better. For example, Internet Explorer 6 
(on A Win2K box) and Netscape 4.78 on the same Solaris box mentioned above use 
much less CPU to draw the page (Netscape ws <10%).

Will try to attach some HTML code and images.

Comment 1

[Russ LeBar]

Attachment: This page reproduces the problem; saved from a view source via Netscape 4.78

Comment 2

[Russ LeBar]

Attachment: Zip file containing all images from the website problem is encountered on. Not all of these will be used in testingC.htm (previously attached).

Comment 3

[Russ LeBar]

Attachment: Yellow Dish image used in testingC.htm. Is in the attached zip file. Attached seperately in case the zip file is inconvenient.

Comment 4

[Russ LeBar]

Attachment: Empty.jpg image used in testingC.htm. Is in the zip file. Provided in case the zip file is inconvenient.

Comment 5

[Russ LeBar]

Attachment: This page reproduces the problem; saved from a view source via Netscape 4.78 then resaved vith Frontpage 2000. The massaging done to the source produces a layout that is not even close to what the actual web app looks like.

Comment 6

[Randell Jesup [:jesup] (needinfo me)]

Confirmed on FreeBSD.

A large part of this is almost certainly 71857.  However, there may be other
issues here hidden by that bug.  I did a jprof of this, and most of the time is
spent in creating and taking down http image requests, which would match 71857.

Comment 7

[Markus Hübner]

There are nice (adjustable per parameter) testcases at

table with pics
http://www.heise.de/ix/browser/tables/index.php?
what=grafik&my_trlimit=100&my_tdlimit=5

table with pics and text
http://www.heise.de/ix/browser/tables/index.php?
what=textgraf&my_trlimit=50&my_tdlimit=3

Comment 8

[Stuart Parmenter]

testing the sites listed here in a trunk build doesn't have any performance
problems.  marking worksforme