Function vm_page_is_valid

freebsd/vm/vm_page.c:5321–5328

* vm_page_is_valid: * * Is (partial) page valid? Note that the case where size == 0 * will return FALSE in the degenerate case where the page is * entirely invalid, and TRUE otherwise. * * Some callers envoke this routine without the busy lock held and * handle races via higher level locks. Typical callers should * hold a busy lock to prevent invalidation. */

 *	hold a busy lock to prevent invalidation.
 */
int
vm_page_is_valid(vm_page_t m, int base, int size)
{
	vm_page_bits_t bits;

	bits = vm_page_bits(base, size);
	return (m->valid != 0 && (m->valid & bits) == bits);
}

/*
 * Returns true if all of the specified predicates are true for the entire