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Wild Penguin

Member

Registered: 2015-03-19

Posts: 399

Firefox memory leak since 119 (or 120)... [SOLVED (for now)]

Hi,

Since recently, I have a problem with Firefox. It will just start increase it's memory usage randomly until OOM killer triggers. It will take a few minutes once it's memory usage starts creeping up, ~10 minutes to consume all of my 32GiB - minus whatever other programs use. If I notice this before OOM kicks in, I can of course close firefox and restart it. Firefox seems responsive even whan starting to use memory (so there is no other way to notice this than looking at memory usage by chance, or until the OOM kills it).

So most of the time, everything is fine, firefox will behave and keep memory usage to a sensible number... until it doesn't. I have no idea how to trigger this at will, it seems somewhat random.

From logs I can see I didn't have this issue before 119, but I can also see I used to be able to use 119 without any apparent memory leaks (EDIT: still happens on 121.0-1).

Has anyone else had problems with Firefox recently? Any sensible workarounds / possible steps for fiixing? I could reset the profile, but I'd rather not as it already has a plethora of settings I need to re-do, many of which I've forgotten but will run into eventually.

By searching, I can find several reports about memory leaks in Firefox but nothing recent (seems like browsers are such huge projects / OSes on their own, that at least on Firefox, memory leaks are a re-occurring theme...)

Last edited by Wild Penguin (2024-01-08 12:08:40)

obap74

Member

Registered: 2021-03-18

Posts: 99

Re: Firefox memory leak since 119 (or 120)... [SOLVED (for now)]

I could reset the profile, but I'd rather not as it already has a plethora of settings I need to re-do, many of which I've forgotten but will run into eventually.

Indeed, but maybe the culprit is something in your profile. Can you reproduce the issue with a fresh profile?

You could also check about:processes (Shift+ESC) with your main profile to see if the memory hog is one of your tabs or extensions.

OpusOne

Member

Registered: 2023-05-31

Posts: 187

Re: Firefox memory leak since 119 (or 120)... [SOLVED (for now)]

I have noticed a significant difference in Firefox's memory management starting with v119, namely its internal garbage collection system.
I have had the symptom you describe once with v119, sudden increase in memory usage in Firefox, that would keep increasing until either I killed it or let OOM do. Haven't been able to find out what would trigger it.
But otherwise, I've seen v119 taking more CPU % on average when "idle" than with previous versions, and was able to pinpoint its GC by opening about:processes.

Things have appeared to be more tamed with v120, and v121 seems to eat less memory after it has run for hours/days than previous versions, so it looks like it has improved.
But they definitely made changes in memory management starting with v119 and I don't know the details of these changes. Maybe someone else does.

Wild Penguin

Member

Registered: 2015-03-19

Posts: 399

Re: Firefox memory leak since 119 (or 120)... [SOLVED (for now)]

For a while, I have just not seen this issue anymore. So it comes and goes, or hopefully, does not come again

I didn't try on a fresh profile as suggested, and that would have been tedious, as while doing that, I can not use the actual profile, and it would have been time-consuming to wait if it does happen on a fresh profile. A reproduction on a fresh profile would be of limited usefulness, but it would have made possible to do a more useful bug report, though.