See testcase, after a while you get an alert that measures the time the marquee took to perform a scrolling operation. With a branch build I get 3953ms as result. With current trunk build, I get 20330ms as result. A regression range would be helpful.

Regression range is http://bonsai.mozilla.org/cvsquery.cgi?module=PhoenixTinderbox&date=explicit&mindate=1196822580&maxdate=1196824139 Caused by Bug 375304 ?

Thanks, yeah, or caused by bug 406568, no idea. In any case, caused by the same person, so blaming is easy ;)

Pretty slow on Mac too. I'll take this one.

Hi all, This was brought to my attention and even though it used to work perfectly, I've moved onto using the much frowned upon <MARQUEE> tag, which works fine for our purposes. The original script was from Dynamic Drive http://www.dynamicdrive.com/dynamicindex2/cmarquee.htm which actually works fine in FF3, but for some reason wasn't fine with other javascript on the page. I actually rewrote the entire proc myself and had the same problem which left me with having multiple onload events as a potential problem... I have this code for the menuing system (still in use and fine)- if (window.addEventListener) window.addEventListener("load", onloadfunction, false) else if (window.attachEvent) window.attachEvent("onload", onloadfunction) else if (document.getElementById) window.onload=onloadfunction and this for the old scroller window.onload=populate Kinda messy but it used to work perfectly... but once again with only one piece of Javascript it's fine.

The previous testcase didn't show the performance issue anymore. However this one still does.

This page should not show anything red.

I think testcase2 is a separate issue that regressed since the 1.9.0 branch split off. Using Linux, I see these results: * testcase1 (attachment 349854 [details]): - takes 16000ms on both today's mozilla-central nightly and Firefox 3.0.4 - takes 2700ms on Firefox2.0.0.17 * testcase2 (attachment 349858 [details]): - is red on today's mozilla-central nightly - is all white on both Firefox 3.0.4 and Firefox2.0.0.17

is http://www.voanews.com/english/2009-01-31-voa8.cfm an example of this? 40-50% cpu in FF 3.1b3, 6% in IE.

Comment on attachment 349858 [details] testcase2 Testcase2 doesn't show anything red anymore, so I guess that has been fixed.

Ok, this is a lot better in current trunk build than it was in a build from 2006, so I think this is worksforme.