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massive memory increase when zooming on what 3 words website




a year ago
a year ago


(Reporter: JMoVS, Unassigned)


48 Branch
Mac OS X

Firefox Tracking Flags

(Not tracked)



(1 attachment)



a year ago
User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:48.0) Gecko/20100101 Firefox/48.0
Build ID: 20160817112116

Steps to reproduce:

 I went to https://map.what3words.com/ehepaar.gefragt.zins , switched the view to "Sattelite" and double-clicked with my mouse 3 times on the image.

Actual results:

 It then started to show the mac os beachball and a look at activity monitor showed that firefox was quickly accumulating memory (54 GB) before my system went out of program memory and simply said "we halted it, do something about it!"

As this is a memory bug and I only know that memory is sometimes security wise very dangerous, I marked this as secuirty relevant for now, correct me if I'm wrong.

Expected results:

No memory blowup up to 54GB.


a year ago
OS: Unspecified → Mac OS X
Hardware: Unspecified → x86_64

Comment 1

a year ago
Not a security bug.
Group: firefox-core-security

Comment 2

a year ago
JMoVS, I tried to reproduce this on a recent Windows nightly but was unable to see a problem. So this could be mac-specific, or related to something else about your setup.

Could you try some of the following steps to help us narrow the problem down, decide priority, and find the right engineering team to help out?:

* Try reproducing this using Firefox safe mode: https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode?redirectlocale=en-US&redirectslug=Safe+Mode If it can't be reproduced in safe mode:
** the problem could be caused by an addon you have installed. You could try disabling all your addons and re-enabling them one by one to see if one of them causes the problem
** the problem could be related to graphics acceleration. In Firefox / Preferences / Advanced / General you could try unchecking "Use hardware acceleration when available" (you will have to restart Firefox)

Otherwise, we measure Firefox memory usage by using a builtin tool "about:memory". When you're seeing the memory problem but before Firefox stops working, could you follow the instructions at https://developer.mozilla.org/en-US/docs/Mozilla/Performance/about:memory to save a memory report file and attach it to this bug report?
Flags: needinfo?(firefox-bugzilla)

Comment 3

a year ago
I tried reproducing it in Safe mode but was partially successful. I loaded up the website, did the steps as provided in the "how to reproduce" section and the website simply stopped being responsive. I was able to switch tabs, open about:memory (attached), but I was not able to show the website again. I was able to "switch" to its tab, it just wasn't displaying the web page at all then.

Comment 4

a year ago
Created attachment 8790273 [details]
Mmeory report from safe mode and not-repsonding website

Comment 5

a year ago
That memory report doesn't show anything unusual; about 20MB for that page, which is well within "normal" for a page of this sort.

When the page is not responding, does Firefox still eat a bunch of memory? If so, we're missing calculating it.

If not, it's likely there are several problems here: perhaps an addon is eating memory, and the site itself is doing a lot of scripting/hanging.

If Firefox with e10s mode stays responsive, and hopefully shows a slow-script dialog, that's about the best we can hope for, and next steps would be with the site itself.

I'm going to close this WORKSFORME, but if you have other evidence that this is a Firefox bug, instead of an addon or website issue, please let me know and we can reopen.
Last Resolved: a year ago
Flags: needinfo?(firefox-bugzilla)
Resolution: --- → WORKSFORME
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