Scrolling performance very slow on URL with latest trunk. Don't know exact regression bug with FF2.0 it works fast. Steps: 1) open URL 2) scroll UP/down with mouse wheel. CPU 1.8GHz, 1Gb Ram, ATI fglrx, Linux.

Over half the time is under nsTextFrame::PaintText. Can you hunt down a regression range for this? That would make it easier to tell what's going on... It would also help to have either a minimal testcase or at least a testcase attached to this bug. Are we invalidating/repainting too much or something? Nominating, but I don't think this should block necessarily. I do think it should be wanted (next or 1.9).

First range: http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/2007/04/2007-04-30-04-trunk/ and http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/2007/05/2007-05-01-04-trunk/

Ah, border rendering. For what it's worth, a minimal testcase would likely help quite a bit here... Specifically, what border styles are causing the slowness?

Looks like dashed borders are no better than dotted ones. This page has a lot of long dashed borders, while a major border rewrite bug is slow scrolling with long dotted borders.

That's a likely possibility, yes. I can't find the bug on slow dotted borders linked from bug 368247, though... What's the number?

Setting to wanted based on comment 1. Unless vlad wants to crank a fix out :-P

There are a bunch of bugs on this currently, none of which are perfectly clean, and this was first, so updating summary, fixing fields, etc. (see also bug 379834, where a much worse case of this problem with a different cause was fixed)

Ah, shoot, didn't see bug 424423 until just now because it wasn't marked a regression from 368247. Marking this depending on that, though it's probably a dupe.

Why did you change URL on https://bugzilla.mozilla.org/attachment.cgi?id=291413 ? Current URL works on trunk faster than on FF2... for me better testcase http://erased.info/post15530 or https://bugzilla.mozilla.org/attachment.cgi?id=310196

romaxa, please just attach whatever page is showing issues to the bug. Linking to sites which may not be around (or might change) tomorrow, is not a good way to get bugs fixed....

romaxa: Sorry, for me attachment 291413 [details] is slower on trunk than 2.0, but only a little bit so you're right it probably doesn't show the same problem. Switching url field to attachment 310196 [details], which won't disappear.

Today I installed Firefox 3 from the previous Firefox 2 stable version. I'm very sad to say that I'm having this same problem affecting my site: http://darkmatters.org There is heavy use of png which I am guessing is the catalyst to this problem. Like Roman this is likely a transparency issue though I can't even guess as to why FF2 works fine but FF3 does not. Scroll lag on my site is very severe in FF3.

Schot, I'm not seeing any dotted or dashed borders on that site. Am I just missing them? If there aren't any, then you're NOT seeing this bug, but another bug. You should file it (and cc me on it).

My mistake Borris. The problem I was having was resolved by changing my background from fixed to repeat. It seems the combination of a fixed Background + the use of transparency or png is causing the slow down/lag I had experienced. I did end up finding the proper reported bug: https://bugzilla.mozilla.org/show_bug.cgi?id=418948

This should be significantly better now after bug 424423 was fixed; can someone who's seeing the problem check with a nightly?

> can someone who's seeing the problem check with a nightly? nothing better with firefox 3.5 on ubuntu. Tested Google Chrome & Opera (scrolling = instant)

(In reply to comment #20) > nothing better with firefox 3.5 on ubuntu. Tested Google Chrome & Opera > (scrolling = instant) Firefox 3.5 != latest nightly; the latest nightly contains Firefox 3.next (Namoroka)-specific code.

"latest nightly" as of when comment 19 was made is over a year ago. 3.5 contains the patch referenced in comment 19.

Firefox 3.5 != latest nightly; ok sry seems that i got something wrong. Thought that this patch must have been included in 3.5. Do you think current nightly will show better scrolling performance?

That patch was in fact included in 3.5; see comment 22.

Isn't this a DUPE of bug 266702?

Here's an example where scrolling is unusably janky on OSX, with a retina screen: http://www.2ality.com/2015/03/es6-generators.html When I plugged in my external non-retina monitor to reduce, the jank is almost gone entirely--but it's still not as smooth as Chrome. There's a single CSS class in this reduced version of that blog page: .post-outer { border: dotted 1px #ccbb99; box-shadow: 0 0 0 rgba(0, 0, 0, .1); }