User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0) Gecko/20100101 Firefox/4.0 Build Identifier: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0) Gecko/20100101 Firefox/4.0 Memory leak after some hours. With only 5 tabs the memory goes above 1GB. Closing tabs doesn't release memory. With MemCleaner I can release 500mb+ only from Firefox. Addons: Firebug Reproducible: Always Steps to Reproduce: 1. Open Firefox 2. Open 15 tabs 3. Close 10 tabs Actual Results: Memory isn't released (leak) Expected Results: Memory to be released (unused) Shouldn't keep memory that is not going to be used or is lost. Windows 7 x64 Firefox 4 RC2 x86 Tabs: GMail, Facebook, Twitter, StackOverflow, Bugzilla, Google

(In reply to comment #0) > Memory leak after some hours. With only 5 tabs the memory goes above 1GB. > Closing tabs doesn't release memory. How long did you wait? Several Seconds/Minutes? Can you provide the Urls to those 15 Tabs?

URLs: - mail.google.com - facebook.com - twitter.com - stackoverflow.com - redimob.com.br - redimob.com.br - redimob.com.br - redimob.com.br + random URLs opened during the day. 5 hours later memory at 1,100,000

I can confirm at least a slow memory rise over a number of hours. I do not see the same values as given above likely because I am using my own general urls so it seems to have more widespread background. My rise is about 100MB per 8 hours of part idle part active use. brunolm7: I think providing a copy of about:memory when its using lots of memory may help in finding the problem or at least say that something needs to be done with bug 633653.

This report does not have enough details to be acted upon usefully. I'm marking it as a duplicate of bug 659855, which is the tracking bug for all memory leaks in Firefox 4 betas. Also, Firefox 5 has better memory behaviour than Firefox 4 (http://blog.mozilla.com/nnethercote/2011/05/25/firefox-5-has-fewer-leaks-than-firefox-4/). You can get a beta version of Firefox 5 from http://beta.mozilla.org.