> Second, you can easily exclude any process from being killed by the kernel's OOM killer: "echo -17 > /proc/PID/oom_adj"

Doing such with a large memory process is a sure way to cause a server to shut down and reboot when it runs out of memory. OOM killer is bad to large memory processes, but the alternative is worse.

Ideally you don't want to swap, you definitely don't want to preemptively swap, but even swapping is better than rebooting a server.