Why no oom kill?

see 1740156 - firefox nightly permits poorly coded site to consume all memory and irretrievably wedge the system

basically, go to portal.examfx.com and just let the login page sit there. in an hour or so it consumes all my 8g ram and 3g swap and irretrievably wedges my system.

i get to that login page frequently, whenever i step away for a few minutes the site logs me out. if i don’t get back in an hour or so i find a wedged system. Just once i got “Gah. Your tab just crashed.” which may have been an oom kill, but usually, no oom kill, and my system gets wedged.

same thing happens in (l)ubuntu or manjaro, i’m using firefox nightly on linux5.16rc4.211205.g0fcfb00-1, tho i expect no difference on other kernels or versions of firefox.

why no oom kill?

Challenge accepted.
See you in an hour or so.

$ free -m
               total        used        free      shared  buff/cache   available
Mem:            6855        3719        1440         227        1695        2683
Swap:           8023        1283        6740

There is. Enable the systemd-oomd service. There are quite a few other alternatives as well, most are available in the AUR.

Looks like that’s designed to kill an entire cgroup, so either my entire session, or at least still all of firefox, unless and until firefox implements giving tabs different cgroups. Does chromium, or another browser, do that?

Ok @gregrwm
Its been ~1hr and while I saw about 600mb used up … thats within the realm of me watching videos etc.

$ free -m
               total        used        free      shared  buff/cache   available
Mem:            6855        4325        1482         217        1048        2090
Swap:           8023        1267        6756

Certainly no crash yet though.

Well how about boot up manjaro-kde-21.2rc1-minimal-211211-linux515.iso, launch firefox, goto portal.examfx.com, and just let it sit. it wedged my system in less than half an hour.

4hrs now … :woman_shrugging:

$ free -m
               total        used        free      shared  buff/cache   available
Mem:            6855        4370         945         241        1539        2017
Swap:           8023        1251        6772

see Why no oom kill? - #6 by gregrwm

I’m not going to spend time checking if default ff does it too right now.
At the very least we can probably conclude for now that it may be configuration related.

i am curious what’s special about your setup that gives you a different result. My system differs very little from as it was installed.

To mind (without getting into about:config…)
I use both PSD (so ff runs in tmpfs) and of course ublock:origin … oh and a GIANT hosts file.

$ wc -l /etc/hosts
285266 /etc/hosts

Whether or not they address this specific issue i would be delighted to learn your recipe for /etc/hosts and about:config.

Sometimes it is an advantage to have older hardware.

When I go to that site, the fan of my laptop immediately begins to ramp up and when I check htop I see that one core (of four) is pretty much all the time working 100%
and memory consumption slowly but steadily rises,
all while I just see a pretty much blank page.

I can hear that something is off and I cannot ignore that noise level.
The site doesn’t show anything useful to me, just some links on the bottom, all producing “Error 1020” - so I close it.

I do have just ublock:origin for a content blocker.

sounds like your ublock:origin setup isn’t blocking whatever invokes this memory bug, tho might be blocking something causing the Error 1020. Yes the page pins one of my cores too.

i’ll try setting up more swap to see if that gives the kernel oom killer the chance it needs to act.

well i still dunno about the koomk but 8g of swap space sure gives ME lots more time to act before the system gets irretrievably wedged, and meanwhile the vicious loss of responsiveness due to thrashing sure gets my attention.

that site (that page) is empty for me and every link on the bottom leads to a Error 1020 access denied

## What happened?

This website is using a security service to protect itself from online attacks.

even with no extensions at all active



leads to that error directly.

strange site

this is however not relevant to why the oom kill does not happen - but I did not let it run that long to even get near that as the fan noise is telling me to just get out of there

10 hours and it couldnt do it. I just closed it …
I will maybe take an appraisal of ff configs if you want to peak at those…
as to hosts file there are many resources … but one that curates a number of lists together is update-hosts-git

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