554301 - Improve memory management (and consumption) greatly

Status: RESOLVED INCOMPLETE

(Firefox :: General, enhancement)

Description

[specialusername]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.2) Gecko/20100316 Firefox/3.6.2
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.2) Gecko/20100316 Firefox/3.6.2

FFox uses a LOT of memory, I have a have a habit to open many tabs and FFox uses sometimes 300MB of RAM and it doesn't decrease the value even when I close all the tabs except last one. Otherwise, great browser.

Reproducible: Always

Steps to Reproduce:
1. Open ffox
2. Open 10 or more tabs
3. Click CTRL-ALT-DEL and see how much memory it's using
4. Close all tabse and see how much memory it still uses


Expected Results:  
Much better memory management.

Comment 1

[specialusername]

"I have a have" = "I have a"*

Comment 2

[Jo Hermans]

If you're assuming that closing a tab should immediately release a lot of memory, then you're wrong. The tab itself is nothing - the memory used by the page (bfcache for instance) is not released with this action, but with others (timers, reference counts, garbage collection, ...) And, most importantly, it depends on the content of the pages - your bug has no specific testcase with repeatable results.

Memory usage is best measured in the special page <about:memory>. Don't use Task Manger for that, that only shows the OS side of it. Firefox can only release memory back to the OS when it's not fragmented, so often it has to wait until more memory is freed and then a very large bunch of memory can be freed all at once (often dozens of megabytes together). What people call memory leaks is often just fragmented memory, for which *nobody* has ever found a definitive solution. Firefox uses the jemalloc library, which is already a very good improvement (much betete than malloc/free), but it can never be perfect.

Closing this bug as incomplete, not that this isn't important, but because it doesn't help the developers at all with a specific problem (there are thousands of similar bugs).

Comment 3

[specialusername]

Thank you for the info.

Comment 4

[specialusername]

Yet, I have to add, FFox "eats" a LOT of memory. Nevermind, go ahead with higher priority jobs.

Comment 5

[specialusername]

This might be some kind of solution:
http://blog.codefront.net/2008/09/10/optimize-firefoxs-memory-usage-by-tweaking-session-preferences/

For me, it's enough for now.

Comment 6

[Jo Hermans]

Changing back to INCOMPLETE, since nothing is fixed here.