1504461 - Firefox freezing with 100% CPU usage for 30-60 seconds when launching Chromium

Status: RESOLVED DUPLICATE of bug 1495900

(Firefox :: Untriaged, defect)

Description

[bytecommander]

User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:63.0) Gecko/20100101 Firefox/63.0

Steps to reproduce:

I can only reproduce this on one of my user accounts on my Ubuntu 16.04 system, 64 bit, Unity desktop, with Firefox 63 and Chromium 70 (same issue before with FF 62 and Cr 69) installed from the official repos.
Other, freshly created user accounts on my system, or the guest account seem not affected.

1. Start Firefox by clicking its icon on the launcher/dash. It can be either my regular profile, private mode, safe-mode with add-ons disabled, or a freshly created new profile without any add-ons or customization. Same issue in each case.

2. Start Chromium by clicking its icon on the launcher/dash. It can again either be the regular profile, incognito mode, or using a temporary profile without any add-ons or customization. Again, same issue in each case. It is not relevant whether there is already another Chromium window open or not.


Actual results:

Chromium starts up normal within a couple of seconds and is ready to use, showing no unusual behaviour.

Firefox instead, despite it has not been interacted with, starts to have all of its processes consume 100% CPU around a second after Chromium was launched. Its overall UI (tab list, menus, scrolling) as well as internal pages (about:xxx) keep working, but any website content is frozen and unresponsive. Switching tabs causes a spinning circle on white background to be shown instead of the rendered website.

After around 30-60 seconds, Firefox turns back to normal again. CPU usage is normal, all frozen parts become responsive again and there's no trace left of the freeze.

A Gecko Performance Profile has been created (using a fresh Firefox profile with only the profiler add-on and all default settings) and uploaded to https://perfht.ml/2zpTWsh - the CPU spike and freeze seems to align with the highlighted section in the Content Process graphs, from around 18-56 seconds.

This has also been posted as question on https://askubuntu.com/q/1076412/367990


Expected results:

Firefox should not be affected at all when Chromium gets launched. It should not suddenly spike in CPU usage and have its website content frozen temporarily.

Comment 1

[Alice0775 White]

probably, this is duplication of Bug 1495900.

Comment 2

[bytecommander]

(In reply to Alice0775 White from comment #1)
> probably, this is duplication of Bug 1495900.

Yeah, that sounds like the same issue to me. Strangely I was not able to find it during my research. Thanks for linking.