52402 - Image cache grows without bounds

Status: VERIFIED INVALID

(Core :: Graphics: ImageLib, defect, P3)

Description

[Simon Fraser [no longer active]]

Currently the image cache seems to grow without bounds; I see no code that would, 
on adding a new image to the cache, flush older cache entries to keep the image 
cache within the specified size.

This really hurts Mac, because the heap gets filled up with GWorld data and we 
crash.

Comment 1

[Simon Fraser [no longer active]]

Note that cache entries _do_ get removed when their image containers are deleted 
on page teardown, so this bug does not lead to a continual increase in memory 
usage. However, opening lots of windows with many images does cause the cache to 
grow unbounded, and of course chrome images are never flushed right now.

Comment 2

[Jim Roskind]

To try to answer the dogfood question, is this "Leak" activity a dominant reason
for a crash, and hence a real dominant reason to not use Nav?

Comment 3

[Simon Fraser [no longer active]]

Yes, this leak is a direct cause of 'out of memory' crashes on Mac. Other changes 
make the Mac less susceptible to out of memory conditions, but they only got 
checked in today. We need some stress testing to see if this bug needs fixing.

Comment 4

[Jim Roskind]

Based on Simon's comment, it sounds like we need some stress re-testing to see 
the impact of this problem.  It is not clear that this is a stopper, so I'm 
marking it dogfood-minus.
It would be good to get the testing info, and use that as input to the beta3 
triage. 

Comment 5

[Simon Fraser [no longer active]]

This bug causes Mac to crash by running out of memory. It needs fixing.

Comment 6

[Gagan]

part of this should get covered by pnunn's recent fix for blocking huge images
from being cached. bug 47660. But I agree that this is important to fix. (though
not a P2)

Comment 7

[hirata masakazu]

I have been seeing the chached images mixed up and displayed in wrong pages (bug 
50357).  Is this bug related to that one?  50357 has been left as unconfirmed for 
some time now.

Comment 8

[Paul Wyskoczka]

Updating QA Contact

Comment 9

[Phil Peterson]

Not holding PR3 for this, marking nsbeta3-. Please nominate for rtm if we really
need to fix this before shipping Seamonkey.

Comment 10

[pnunn]

il_cache.bytes keeps track of bytes currently in
use by imgcache. 
il_cache.max_bytes keeps track of the largest size requested 
for allocation in the image cache. It is a 'high water' mark.
This value DOES NOT mean the imgcache is growing without bounds.
If a very large image is requested, currently there is no code
that prevents its addition to the image cache. It would cause
a purging of the cache to unload images. This means the cache
can temporarily go over its 2M upper limit.

marking Invalid.
-pn

Comment 11

[pnunn]

Please note: The mac's memory problems should be addressed
by bug#47660. 

Comment 12

[Terri Preston]

As per pnunn's comments, I am marking verified