Linux will free memory that's backed by files, and load it again when it's needed. Under heavy memory pressure this has the same effect as swap thrashing, even

Linux will free memory that's backed by files, and load it again when it's needed. Under heavy memory pressure this has the same effect as swap thrashing, even if you have swap disabled. The kernel's out-of-memory killer does not help, because it's designed to work only as a last resort, and the system is still technically making progress despite being unusable in practice. AFAIK no other mainstream OS has this problem. The solution is running a userspace out-of-memory killer, e.g. earlyoom.