Overcommitting means providing more virtual memory to be mapped than is available in physical memory. It works by mapping memory as readonly, mapped to a zero p

Overcommitting means providing more virtual memory to be mapped than is available in physical memory. It works by mapping memory as readonly, mapped to a zero page, and "committing" a real physical page when a write occurs to a page for the first time. The act of asking for virtual memory and mapping it is considered allocation. Linux overcommits virtual memory. Some OS, like Windows, actually commit physical pages to back virtual memory when you ask try to map new virtual memory. I think you know these things and it's mostly just a semantics argument, but this is the widely agreed definition.