I’m not sure how this works on Linux exactly but in principle you don’t need to support overcommit to avoid that problem. On illumos for example anonymous memory allocations come from swap, which is a virtual resource that includes both disk and memory. You do still have this problem if something is using more than half of swap, but (1) that’s much larger, and (2) you can augment it with more disk space, which won’t actually be used unless stuff actually uses all the physical memory. This has its own tradeoffs but it’s useful to keep in mind that there are other ways to do things.