There's a switch you can toggle that will turn off the OOM (vm.overcommit_memory). The downside is memory allocations that would oversubscribe memory will imme

There's a switch you can toggle that will turn off the OOM (vm.overcommit_memory). The downside is memory allocations that would oversubscribe memory will immediately fail. That means processes won't be able to allocate tens of gigabytes of virtual memory anymore. If I understand the limitation correctly, this also means that all process's allocated virtual memory can no longer exceed the amount of physical+swap memory in the machine. I think this probably interacts badly with COW memory semantics for child processes: even though children and parent reuse address space, the kernel can't know whether the child will write to the memory it inherited from its parent's memory map. I think if the kernel is being too careful, all "shared" memory would have to be accounted separately, which would severely limit the number of processes you could have open. (Is that really what happens? That seems awfully limiting. I hope I'm wrong.)