26028 - extremely long delay after loading page

Status: VERIFIED DUPLICATE of bug 29641

(Core :: Layout, defect, P3)

Description

[Chris Waterson]

pav and I were playing around with the above web page, which is a 3,000 element
server-generated HTML directory listing. We saw that the document would layout
out fairly quickly (about 30sec on an opt win32 build 300Mhz PII), during which
time the UI is marginally responsive (e.g., you can mouse over menus and stuff).
But then, WHAM! The UI would lock up for another 50 to 60 seconds.

We broke into the code, and as best as we two layout neophytes could tell, it
looked like the final content appended (received from the close </pre> tag) was
triggering a complete reconstruction of all the frames, possibly in some
degenerate way that was causing block frames to reflow themselves multiple times.

We tried this with nisheeth's fancy prefs as well, and got basically the same
results.

Any clue as to what might be going on here?

Comment 1

[troy]

My guess would be the dreaded WipeContainingBlock() or ReframeContainingBlock() 
frame construction code that Kipp added just before leaving. It's simple enough 
to tell, just set a breakpoint in those two places and see if we hit it.

If so, just give the bug to me

Comment 2

[Tomi Leppikangas]

I see similar problems with page
http://www.student.oulu.fi/stats/Jan.wwwstats.html

I notised that prefs makes big difference to this, if i set:
user_pref("content.notify.backoffcount", 2);
user_pref("content.notify.interval", 250000);
user_pref("content.notify.ontimer", true);

Page loads under minute, no reflowin thought. I debugged a  bit with bigger
backoff count, and notised that nsRegionGTK::Union gets called zillion times
at end of page load. I attach a patch that i used for debugging (just
one line prinf).

It prints something like this at end of page loaad when ui gets stuck:

nsRegionGTK::Union(8, 571618, 1, 1)
nsRegionGTK::Union(8, 571632, 1, 1)
nsRegionGTK::Union(8, 571646, 1, 1)
nsRegionGTK::Union(8, 571660, 1, 1)
nsRegionGTK::Union(8, 571674, 1, 1)
nsRegionGTK::Union(8, 571688, 1, 1)
nsRegionGTK::Union(8, 571702, 1, 1)
nsRegionGTK::Union(8, 571716, 1, 1)
nsRegionGTK::Union(8, 571730, 1, 1)
nsRegionGTK::Union(8, 571744, 1, 1)
nsRegionGTK::Union(8, 571758, 1, 1)
.
.
.

Comment 3

[Tomi Leppikangas]

Attachment: Patch to see calls to nsRegionGTK::Union

Comment 4

[Oliver Klee]

Is this still a problem with the latest nightlies?

Comment 5

[Chris Waterson]

Ok, this is a dup of bug 29641. (Sorry it took me so long to figure that out!)

*** This bug has been marked as a duplicate of 29641 ***

Comment 6

[Chad Austin]

verified dup

(page in URL no longer exists)