> every process is supervised by some other process which will restart it on failure

I'm curious if this works in practice for you. The current OOM algorithm in Linux sums up the memory usage of a process and all its children. So there are good chances that the restarter process is killed first, and then the main software is killed too (when OOM killer realizes the last kill didn't free enough memory).

This is exactly the problem we're facing at work here: on a computational cluster, users sometimes start wild code that consumes all the memory, but the OOM decides to kill the batch-queue daemon first, because it's the root of all misbehaving processes. We have to explcitly set `oom_adj` on the important daemons to prevent the machines from becoming unresponsive because of a bad OOM decision.