111784 - Mozilla very slow in loading this page

Status: VERIFIED DUPLICATE of bug 98118

(Core :: Networking: HTTP, defect, P3)

Description

[David G King]

From Bugzilla Helper:
User-Agent: Mozilla/5.0 (Windows; U; Win98; en-US; rv:0.9.4) Gecko/20011019
Netscape6/6.2
BuildID:    0.9.6

After entering URL, Mozilla hangs and I need to use CTRL-ALT-DEL to end the
process. It loads fine with Netscape 6.2 and from looking at the page source, I
suspect it is a JavaScript problem (but that is a guess).

Reproducible: Always
Steps to Reproduce:
1. Ctrl-L
2. Enter www.worldrugbyshop.com
3. Press Enter

Actual Results:  Hang.

Expected Results:  Page load.

Comment 1

[R.K.Aa.]

WFM on a 8 h. old Linux build. I see a 10 sec. "freeze" before page suddenly
renders as a whole.

Comment 2

[Karl Johan Kleist]

WFM. Build ID: 2001 11 23 03. Windows 2000.

No hang, that is. However I note a few odd things:

- The page takes quite long thing to load. If I go to it, then to somewhere else,
  and then "go back", loading takes approx. 2 seconds during which the pointer
  toggles between normal and hourglass all the time. This is a long time for a
  page with a few small images on my 850 MHz / 256 MB machine.

- After hiding the window, when placing it on top again, layout takes a second.
  Normally, this is more or less instantaneous.

- "View Source" takes almost ten seconds.

Comment 3

[David G King]

The delay happens under Netscape 6.2 as well, however, the big and important 
differance is that the page is partially rendered before the delay happens.

Under 0.9.6 on Win 98se I see the pointer change from normal to hourglass for a
bit before that stops. The longest I've waited is about 2 mins (Cable modem, AMD
K62-500, 384Mb RAM).

Comment 4

[David G King]

More info.

0.9.6 doesn't hang. What happens is that it takes 3-4 minutes to load the page,
and  the page suddenly appears.

Important note, Netscape 6.2 (aka Mozilla 0.9.4.1) loads the entire page far
quicker (less than a minute). And, as I said before, it displays a partial page
almost instantly.

Comment 5

[David G King]

I've just tested using a new build 2001112603, and it works better. That is, a
partial page is rendered instantly, but the rest still takes almost 2 minutes to
load.

Comment 6

[Phil Schwartau]

Attachment: Try loading this off the Bugzilla server

Comment 7

[David G King]

That attachment took 4.5 minutes to load. It should be noted, for what it's
worth, that the "throbbing" M doesn't advance during the page load.

Comment 8

[David G King]

Just tried www.worldrugbyshop.com using Mozilla 2001112803 and it still takes
4.5 minutes to load. Any progress on this?

Comment 9

[Phil Schwartau]

Confirming bug, changing OS : Win98 ---> All, reassigning to Layout component.
My timings to load http://www.worldrugbyshop.com using recent Mozilla trunk 
binaries on WinNT, Linux, Mac9.1: 

25 seconds on WinNT, Linux
12 seconds on Linux

On my WinNT box, I have IE6 installed. It loads the site in 5 seconds.
I have determined this is not a JavaScript Engine issue, by modifying
the HTML to remove all the JavaScript. I will attach this below. 
Mozilla still takes 5 times longer to load it than IE6. In addition,
I notice what Svante observed in Comment #2:

- After hiding the window, when placing it on top again, layout takes a second.
  Normally, this is more or less instantaneous.

Comment 10

[Phil Schwartau]

Attachment: HTML with no JavaScript; still takes Moz a long time to load

Comment 11

[David G King]

I concur, it's not the Javascript, as your HTML (without JS) took the same time
as always to load....this time using a version of Mozilla that I'd pulled and
built this afternoon.

Comment 12

[Kevin McCluskey (gone)]

Adding perf keyword. Downgrading from critical to normal since it doesn't hang.

Comment 13

[rubydoo123]

using the build from 20011212 on win98, it took 18s to completely load. It took 
9s on IE6 and on 4.x it seems to load for just under a minute. The load time, 
although longer than in IE, is much improved from the initial report. Setting to 
P3

Comment 14

[David G King]

Using build 2001121303 it just took me 5.5 minutes to load from example from
Bugzilla.

Using the exact same procedure using IE 6.0, it took 6-7 seconds.

This is on an AMD K6-2 500 with 382Mb Ram and a cable modem.

Something is really really wrong here.

Comment 15

[Marc Attinasi]

It is taking forever to load from Bugzilla (or a local file), but every time I
break in the debugger to see what it is doing, it is just waiting for something.
 There is no LAYOUT happening in any thread.  I think this is probably a
netwerking issue, but I cannot prove it yet. It could also be a problem with
detecting when the document has completed loading, as it appears to be loaded
long before the throbber stops.  

BTW: fixing the bogux <style="blahblah"> tags does not change anything...

Comment 16

[David G King]

I have to agree with Marc in #15. I've noticed that all network activity stops
on my cable modem long before the page is rendered.

So, either this page is really complex (which I don't think it is), or as Marc
also suggests, Mozilla hasn't noticed that it has finished loading the page and
can start rendering.....assumming that a partial rendering during page load
isn't possible.

Comment 17

[David G King]

OK, some more info.

Under a fresh (read clean) install of 2002010403, I got the page to load from
bugzilla in about 20 secs.

As a test, I turned off the "Enable keep alive" in
Edit-Preferences-Debug-Networking, restarted Mozilla, cleared disk and memory
cache, and the load time dropped to 12 seconds.

This seems to support you thought about this being a networking issue, possibly
with the implementation of HTTP 1.1?

Comment 18

[Marc Attinasi]

Over to networkign to investigate.

Comment 19

[neeti]

http: looks like disabling Keep Alive reduces page load time

Comment 20

[Darin Fisher]

is anyone experiencing this problem with a recent nightly build?  and if so, are
you connecting via a proxy server to the internet?  thx!

Comment 21

[Darin Fisher]

just tested this using the 2002-02-04/21 linux build and the page seems to load
plenty fast.  roughly 5 seconds from cache and maybe 10 seconds via DSL. 
view->source on the other hand seems to still take longer than it should...
approximately 10 seconds.

so, i'm going to say that whatever bug was plaguing us has been fixed...
however, view->source is really really inefficient in parsing this page.

chak: can you take a look at this bug?  are you the viewsource owner?

Comment 22

[Chak Nanga]

Hi Darin : I did the initial implementation and have not worked on it much ever
since. bzbarsky knows a lot more than i do about viewsource: now.

Cc:ing Boris

Comment 23

[Boris Zbarsky [:bzbarsky]]

Attachment: jprof of loading this page's source

Note that view source spends 67% of its time in nsJISx4501LineBreaker::Next. 
That would be bug 98118.

Comment 24

[Darin Fisher]

bz: thx for the info... marking as DUP since that most likely explains what's
going on here.

*** This bug has been marked as a duplicate of 98118 ***

Comment 25

[John Unruh]

Verified dupe.