Comment by jeffbee
21 hours ago
Unfortunately Linux makes it difficult to fully get away from swapping because any file-backed page is eligible to be evicted, and even if you have "disabled swap" the kernel will cheerfully page-out your program, even if it needs to be immediately paged in again to continue. The only way to stop it from doing so is to remap all executable mappings into anonymous memory, a thing which is possible but which the loader and linker do not make easy.
This type of thrashing was the most common OOM issue I saw on my servers, the system would effectively deadlock until I pulled the plug. In my setup this seemed to be caused by slow-ish disks, and using a small amount of zram made things more CPU-bound / less IO-bound. I haven’t seen the problem since, the OOM killer does what I expect.
Tbh hadn't heard about zram in Linux until now, I'll try it
I ran into this last night and learned about it. At 3am.