Robert William Fuller wrote: > Linux doesn't commit mapped memory until it's faulted. As for other > platforms, who knows?
Correction: most Linux installations don't commit mapped memory until it's faulted. A few do, as a matter of policy (it depends on kernel settings), so that applications won't randomly crash when too much memory is faulted, but will return 0 from malloc() earlier. For those few systems, use MAP_NORESERVE if you still need to allocate the address space. -- Jamie