Memory Leak 58.0.1 (64-bit)




16 days ago
2 days ago


(Reporter: Alex, Unassigned)


58 Branch

Firefox Tracking Flags

(Not tracked)


(Whiteboard: [MemShrink])


(3 attachments)

240.00 KB, application/x-gzip
449.69 KB, image/png
258.49 KB, application/x-gzip


16 days ago
Created attachment 8948849 [details]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:58.0) Gecko/20100101 Firefox/58.0
Build ID: 20180128191252

Steps to reproduce:

To reproduce, you need to use Firefox (Version 58.0.1 64-bit) for around 3-4 hours. Open multiple tabs and have sites like YouTube or a stock ticker open (sites that aren't static) so you're continuously loading new data.

Actual results:

After about 3-4 hours Firefox's RAM and CPU usage hit 90-100%. The browser is no longer able to load new webpages or refresh existing ones. They will load indefinitely. This has affected all three of my Windows 10 computers using Firefox as well as all of my coworkers using Firefox as their main browser.

Expected results:

Firefox should not try to allocate all of my computer's resources.


15 days ago
Whiteboard: [MemShrink]
User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:58.0) Gecko/20100101 Firefox/58.0

I've tested this issue Windows 10 x64 with the latest Firefox release (58.0.2) and the latest Nightly (60.0a1-20180209005628) and haven't managed to reproduce the issue.
After loading multiple tabs (20) youtube, vimeo pages and also other webpages like facebook, twiiter, etc. The RAM memory and CPU usage was below 20%. No hangs, latency or other issues occured.

Can you please specify the number of tabs you have had loaded?

Could you also please retest this using the latest Firefox release and latest Nightly build and report back the results? When doing this, please use a new clean Firefox profile, maybe even safe mode, to eliminate custom settings as a possible cause (

Comment 2

10 days ago
Thanks Emil. The number of tabs varies. It's generally 10+

I'm testing on safe mode now. I'll report back as soon as I know if this fixes it. If I do run into this again, is there any specific info you would need?
Flags: needinfo?(likalex3)

Comment 3

8 days ago
Created attachment 8951411 [details]

Comment 4

8 days ago
Running in safe mode prevents FF from freezing, but it still gradually eats through my RAM and CPU until it hits 100%. This is in safe mode. I tried on my home desktop and laptop with the same results.
Flags: needinfo?(likalex3)
Comment hidden (metoo)
(In reply to Arseny from comment #5)
> I reported this in another branch already but want to repeat it here: I am
> having the same problem with 58.0.2 I am on Win 7 64bit. At different times
> I have 30-50 tabs opened (mostly text pages with minimum graphic content)
> and adblock origin active (no other addons, default profile etc). Leaving
> this overnight leads to massive amounts of RAM taken by firefox (one process
> being a gig or few gigs, others ~400-300mb each). If left open it sooner or
> later eats all RAM available slowing PC to a crawl. If I close firefox and
> then reopen it restoring all tabs it only takes ~600mb total (250mb one
> firefox process and others are about 100mb each).

Please file a separate bug.
The memory report seems to be broken. Can you take a memory report before you see issues, wait until things get bad and take another memory report we'll be able to diff them and see what's going on. Also if you feel comfortable can you provide a link to the stock ticker you are using?
Flags: needinfo?(likalex3)

Comment 8

2 days ago
Yep, not a problem.

Just a quick update to go along with my memory report. I decided to switch to an another laptop. I performed a factory restore of Windows 10 and a clean install of FF x64. The CPU and RAM issue returned immediately, despite the clean install. I've used safe mode and regular browsing mode.

Each time FF eats up all my CPU and RAM I'm browsing a different set of sites. I haven't used the stock ticker since Monday, just to see what happens.

The only constant that comes to mind is that I'm using FF x64. I have not tried the x86 version yet.

The stock ticker I use is Yahoo! Finance

Please let me know if you need anything else.
Flags: needinfo?(likalex3)

Comment 9

2 days ago
Created attachment 8952887 [details]

Comment 10

2 days ago
Also feel free to shoot over any troubleshooting steps you think might help. I used to work in IT, so nothing is too technical.
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