294324 - scrolling performance regression

Status: RESOLVED FIXED

(Core :: Web Painting, defect)

Description

[Peter van der Woude [:Peter6]]

Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.8b2) Gecko/20050515
Firefox/1.0+ ID:2005051512

repro:
1.Open FF
2.open http://tinderbox.mozilla.org/showbuilds.cgi?tree=Firefox (or any larger page)
3.put mouse on right scrollbar and pull down

this regressed between the 
firefox-1.0+.en-US.win32_20050515_1255pdt and
firefox-1.0+.en-US.win32_20050515_1642pdt builds

http://bonsai.mozilla.org/cvsquery.cgi?treeid=default&module=PhoenixTinderbox&branch=HEAD&branchtype=match&filetype=match&whotype=match&sortby=Date&hours=2&date=explicit&mindate=2005-05-15+12%3A55%3A00&maxdate=2005-05-15+16%3A05%3A00&cvsroot=%2Fcvsroot

prime suspect bug 293453

Comment 1

[Steve England [:stevee]]

Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.8b2) Gecko/20050515
Firefox/1.0+ ID:2005051518
Scrolling is fast and responsive for me on that page with a new profile and both
with smooth scrolling on and off. Using the mouse wheel, or dragging the
vertical scrollbar, or clicking on the scrollbar arrows all results in fast and
smooth scrolling.

Comment 2

[Steve England [:stevee]]

Actually...

Although scrolling remains smooth for me (AthlonXP 2400) CPU usage has increased
dramatically. And IIRC peter has a Duron 700 so any regression will be more
obvious for him.

With Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.8b2) Gecko/20050515
Firefox/1.0+ ID:2005051506 and scrolling up and down on news.bbc.co.uk I get
spikes to <20% CPU time used.

But with Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.8b2)
Gecko/20050515 Firefox/1.0+ ID:2005051518 and scrolling up and down on
news.bbc.co.uk I get 99% CPU time used constantly.

Comment 3

[Fred Collier]

I've got an old, slow machine. This will drive me to IE if it continues.

Mozilla/5.0 (Windows; U; Win95; en-US; rv:1.8b2) Gecko/20050516 Firefox/1.0+

Comment 4

[Ria Klaassen (not reading all bugmail)]

On this WinXP system with an AMD Athlon 2000+ I have problems as well.
This site used to scroll perfect with Smoothwheel, but now it trembles like a
jelly pudding when scrolling down: http://www.prikpagina.nl/list.php?num=571

Comment 5

[Ria Klaassen (not reading all bugmail)]

14 May official nightly still worked fine...

Comment 6

[Pardal Freudenthal (:ShareBird)]

The problem I noticed wich I'd call a scrolling issue regression isn't related
to any specific site. I've seen the mouse scroll wheel becomes unresponsive
sometimes with a lot of CPU usage.

Comment 7

[Tuukka Tolvanen (sp3000)]

I'm also getting much less fps scrolling on linux gtk2 fx 2005-05-16-08Z
compared to 2005-05-05-13Z (K7-600). If we define "fast scroll" vs "slow scroll"
as "scrolling fast enough that the whole content has to be redrawn at each
step", it feels like slow scroll and fast scroll on 2005-05-16-08Z give about
the same fps as fast scroll on 2005-05-05-13Z.

Comment 8

[Tuukka Tolvanen (sp3000)]

speaking of overflow children or somesuch (bug 293453 comment 2), I can
reproduce similarly choppy scrolling in an earlier build by placing the
autoscroll anchor near content edge so it's partially under the scrollbar or
other edge.

Comment 9

[Ria Klaassen (not reading all bugmail)]

I tried it out on a WinXP computer with an AMD Duron 900 MHz processor and I can
say that scrolling is horribly slow on nearly every site I tried. Also on this
computer is Smoothwheel installed and Firefox scrolls with delays and jumps. I
saw a high processor usage but never 100% (mostly between 20% and 70%)

This computer worked perfectly normal before.

Comment 10

[Dennis Jacobfeuerborn]

I see the same problem on: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8b2)
Gecko/20050516 Firefox/1.0+ running on Linux.

Here are my observastions:
When I go to http://www.larian.com/nextgen.php the page scrolls *extremely*
slowly and FF eats pretty much all available CPU cycles. So I saved the complete
page and opened the local version. The result was the the page scrolled just
fine however I also noticed that apparently the background had not been saved by
FF (bug?). After downloading the background manually and adding the background
attribute to the body-tag of the saved page the scolling problem appeared again.

Comment 11

[Mike Connor [:mconnor]]

roc, bz, any ideas here?  There's definitely a CPU spike here, I can get one of
my  processors to hit almost 100%, which is really excessive...

Comment 12

[Boris Zbarsky [:bzbarsky]]

Chances are, we're invalidating too much.  I'll try to check when I get home, I
guess; in the meantime if someone has a debug build, paint flashing is your friend.

Comment 13

[anonymous]

(In reply to comment #10)
> I see the same problem on: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8b2)
> Gecko/20050516 Firefox/1.0+ running on Linux.
> 
> Here are my observastions:
> When I go to http://www.larian.com/nextgen.php the page scrolls *extremely*
> slowly and FF eats pretty much all available CPU cycles. So I saved the complete
> page and opened the local version. The result was the the page scrolled just
> fine however I also noticed that apparently the background had not been saved by
> FF (bug?). After downloading the background manually and adding the background
> attribute to the body-tag of the saved page the scolling problem appeared again.

Scrolls fast for me, but cpu usage is around 50% just when scrolling.

P4/266mhz
1gig ram
radeon 9800pro
Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8b2) Gecko/20050516
Firefox/1.0+ ID:2005051617

Comment 14

[Boris Zbarsky [:bzbarsky]]

> paint flashing is your friend.

Indeed.  In a build without the patch for bug 293453 we repaint the
newly-exposed strip and the scrollbar.  In a build with that patch we repaint
the entire viewport.

Comment 15

[José Jeria]

*** Bug 294462 has been marked as a duplicate of this bug. ***

Comment 16

[logan]

400MHz celeron in Linux, man that's horrible.. Pages keep scrollin up/down long
after I stop. :)

Comment 17

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Attachment: fix

Frames that are clipped by a scrolling view should not be marked as transparent
just because they're overflowing.

Comment 18

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Comment on attachment 183858 [details] [diff] [review]
fix

scrolling performance regression fix, low risk

Comment 19

[Dennis Jacobfeuerborn]

Patch fixed the problem for me though scrolling is still a lot slower on the
page I mentioned and the CPU usage of X shoots up into the 90% range on
scrolling. Could it be that FF hits a particular slow codepath of XOrgs radeon
driver?

Comment 20

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Some pages scroll slowly, and always have. We're not going to fix all of them now.

Comment 21

[Mike Shaver (:shaver emeritus)]

Comment on attachment 183858 [details] [diff] [review]
fix

a=shaver, please commit quickly.

Comment 22

[Mike Connor [:mconnor]]

checked in so we get this in nightlies.