Of course, it's not a guarantee. But if your program is under heavy pressure from other programs, it won't continue to run in any reasonable sense either, even

Of course, it's not a guarantee. But if your program is under heavy pressure from other programs, it won't continue to run in any reasonable sense either, even without Linux's OOM-killer. Yes, you can show an error message, but then the only safe thing to do is quit. You won't even be able to clean up any on-disk swap files properly, let alone handle user interactions. Handling this is hard in desktop applications. For servers, you can have known workloads with better limits on each process.