The pmap_zero_page function zero-fills an entire page using machine-dependent optimizations. The pmap_zero_page_area function is used to zero-fill an area of a page. The range specified must not cross a page boundary; it must be contained entirely within a single page.
The pmap_zero_page_idle interface is used by the vm_pagezero process. The system-wide Giant lock should not be required to be held in order to call this interface.
This function is required to be implemented for each architecture supported by