User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:75.0) Gecko/20100101 Firefox/75.0

Steps to reproduce:

Computer hasn't been shut down since yesterday but somehow Firefox has accumulated at least 14GB of RAM but about:performance doesn't even list that much being used by tabs

I've attached a memory report of this happening before as well

This is the about:performance screenshot mentioned earlier

Resetting severity to default of --.

Hi
Its hard to replicate this, im using windows10 64bit and the latest Firefox release release 75

can you check if issue still happens on the latest nightly build?
Please retest issue on latest nightly build, can be downloaded from here: https://nightly.mozilla.org/ and retest the problem.

With a new profile: you have the steps here:https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles?redirectlocale=en-US&redirectslug=Managing-profiles#w_starting-the-profile-manager

Lastly test if the issue is reproducible in safe mode, here is a link that can help you:
https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode

Regards
Pablo

Not sure how to reproduce this, just sometimes I would leave my computer on for a couple days and come back to see it used a bunch of RAM

Because this bug's Severity has not been changed from the default since it was filed, and it's Priority is -- (Backlog,) indicating it has has not been previously triaged, the bug's Severity is being updated to -- (default, untriaged.)

Hi
can you please try with the latest Firefox Nightly with a clean profile and let me know if you still experience the problem?

Please retest issue on latest nightly build, can be downloaded from here: https://nightly.mozilla.org/

With a new profile: you have the steps here:https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles?redirectlocale=en-US&redirectslug=Managing-profiles#w_starting-the-profile-manager

thanks.
Pablo

Hi Andrew

Do you know what is the correct component for this bug? there is a memory report attached but there is no clear way on how to reproduce it.

thanks

Wow, I see 21,973.47 MB (97.62%) ── heap-unclassified in the memory report for one of the content processes. That's a lot of memory!

I also see a lot of DevTools related memory in the main process:
2,023.94 MB (17.52%) -- realm([System Principal], DevTools (UI loader))
754.23 MB (06.53%) ++ realm([System Principal], DevTools (Module loader))

So maybe the content process heap-unclassified is also related to DevTools? If nothing else, probably understanding why the main process is using around 3GB for DevTools would be good, so I'll move it there.

Might close as duplicate of Bug 1682212, which seems to have reproducible STRs

Let's keep the discussion on Bug 1682212 which has good STRs.