Memory overcommit

Memory overcommit

You're right, it is sometimes preferable to have applications be killed rather than being unable to log into the machine. But even here the OOM killer seems like a useful sticking plaster rather than fixing the real problem. It would be better to have 5% of physical memory reserved for root (or for an interactive 'task manager' that lets you kill misbehaving apps), in the same way that 5% of disk space was traditionally reserved.

If the I/O scheduler were a bit smarter, then the swapping activities of processes would count against their I/O usage, so a single bloated Firefox process would not be able to monopolize the disk to the exclusion of everything else. Similarly there could be more fairness in physical RAM allocation, so it wouldn't be possible for one app to consume all the physical memory pushing everything else into swap; it would be limited to say 80%. (This is reasonable for desktop systems, of course for servers or number-crunching you don't care so much about interactive performance so you'd increase that figure.)