Firefox memory leaks

[Morlan]

Why is Firefox 3.0.4 using 160MB RAM even after I´ve closed all tabs? It uses about 27MB on fresh start so what is it doing with the remainder 130MB? Is this normal?

 

[Morlan]

It'll drop eventually (or be unused but left in the middle of an allocation until the whole lot gets swapped out), but it isn't a leak - for one, if you opened the tabs again you should find the memory usage doesn't increase as much.

What was in the tabs? Plugins are notoriously bad for messing with memory usage.

Hi Tolien. The mem usage doesn´t drop. I took that screen grab after returning to my PC after a few hours (and the system wasn´t on standby).

I often use Adobe PS, Illus, Flash and DW all together, which take up a huge amount of RAM, but Firefox still sits there hogging a 160MB for nothing.

I haven´t experienced this problem in Safari or Chrome. I don´t use IE enough to compare.

I usually restart FF every hour to clear up memory. I love FF but the hogging of RAM really annoys me.

 

[Morlan]

Hi Tolien,

Thanks for helping me with this.

I started FF in Safe Mode. The homepage is about:blank

On fresh start, and leaving it for 10 mins, task manager reports 18.8MB mem usage.

Memory cache device

Number of entries: 30
Maximum storage size: 24576 KiB
Storage in use: 342 KiB
Inactive storage: 0 KiB

After an hour of surfing, and then closing all tabs and leaving the browser for 30 mins, the mem usage settles at around 160MB

Number of entries: 620
Maximum storage size: 24576 KiB
Storage in use: 134240 KiB
Inactive storage: 0 KiB

All of the entries are for .JPEG, .GIF, .PNG and .ICO, from websites I have visited in the past hour. The entries have expiry dates from 1970 all the way up to 2038. Many have no expiry dates. Are these dates defined in the websites´cookies?

My understanding is that when/if I revisit these websites, FF loads the images from cache. I visit Digg a lot, so the majority of entries are for sites that I will never visit again, so I would have expected FF to drop these entries from the cache as soon as I close the tab.

Is this normal behaviour? Any suggestions?

Many thanks