From "Artem S. Tashkinov" <> Subject Let's talk about the elephant in the room - the Linux kernel's inability to gracefully handle low memory pressure Date Sun, 4 Aug 2019 09:23:17 +0000 Hello,



There's this bug which has been bugging many people for many years

already and which is reproducible in less than a few minutes under the

latest and greatest kernel, 5.2.6. All the kernel parameters are set to

defaults.



Steps to reproduce:



1) Boot with mem=4G

2) Disable swap to make everything faster (sudo swapoff -a)

3) Launch a web browser, e.g. Chrome/Chromium or/and Firefox

4) Start opening tabs in either of them and watch your free RAM decrease



Once you hit a situation when opening a new tab requires more RAM than

is currently available, the system will stall hard. You will barely be

able to move the mouse pointer. Your disk LED will be flashing

incessantly (I'm not entirely sure why). You will not be able to run new

applications or close currently running ones.



This little crisis may continue for minutes or even longer. I think

that's not how the system should behave in this situation. I believe

something must be done about that to avoid this stall.



I'm almost sure some sysctl parameters could be changed to avoid this

situation but something tells me this could be done for everyone and

made default because some non tech-savvy users will just give up on

Linux if they ever get in a situation like this and they won't be keen

or even be able to Google for solutions.





Best regards,

Artem



