Function vm_domain_alloc_fail

freebsd/vm/vm_page.c:3291–3310

* vm_domain_alloc_fail: * * Called when a page allocation function fails. Informs the * pagedaemon and performs the requested wait. Requires the * domain_free and object lock on entry. Returns with the * object lock held and free lock released. Returns an error when * retry is necessary. * */

 *
 */
static int
vm_domain_alloc_fail(struct vm_domain *vmd, vm_object_t object, int req)
{

	vm_domain_free_assert_unlocked(vmd);

	atomic_add_int(&vmd->vmd_pageout_deficit,
	    max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1));
	if (req & (VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL)) {
		if (object != NULL) 
			VM_OBJECT_WUNLOCK(object);
		vm_wait_domain(vmd->vmd_domain);
		if (object != NULL) 
			VM_OBJECT_WLOCK(object);
		if (req & VM_ALLOC_WAITOK)
			return (EAGAIN);
	}

	return (0);
}

/*
 *	vm_waitpfault: