Function vm_page_alloc_contig_domain

freebsd/vm/vm_page.c:2257–2398

}

vm_page_t
vm_page_alloc_contig_domain(vm_object_t object, vm_pindex_t pindex, int domain,
    int req, u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment,
    vm_paddr_t boundary, vm_memattr_t memattr)
{
	struct vm_domain *vmd;
	vm_page_t m, m_ret, mpred;
	u_int busy_lock, flags, oflags;

	mpred = NULL;	/* XXX: pacify gcc */
	KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) &&
	    (object != NULL || (req & VM_ALLOC_SBUSY) == 0) &&
	    ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) !=
	    (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)),
	    ("vm_page_alloc_contig: inconsistent object(%p)/req(%x)", object,
	    req));
	KASSERT(object == NULL || (req & VM_ALLOC_WAITOK) == 0,
	    ("Can't sleep and retry object insertion."));
	if (object != NULL) {
		VM_OBJECT_ASSERT_WLOCKED(object);
		KASSERT((object->flags & OBJ_FICTITIOUS) == 0,
		    ("vm_page_alloc_contig: object %p has fictitious pages",
		    object));
	}
	KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero"));

	if (object != NULL) {
		mpred = vm_radix_lookup_le(&object->rtree, pindex);
		KASSERT(mpred == NULL || mpred->pindex != pindex,
		    ("vm_page_alloc_contig: pindex already allocated"));
	}

	/*
	 * Can we allocate the pages without the number of free pages falling
	 * below the lower bound for the allocation class?
	 */
	m_ret = NULL;
again:
#if VM_NRESERVLEVEL > 0
	/*
	 * Can we allocate the pages from a reservation?
	 */
	if (vm_object_reserv(object) &&
	    (m_ret = vm_reserv_alloc_contig(object, pindex, domain, req,
	    mpred, npages, low, high, alignment, boundary)) != NULL) {
		goto found;
	}
#endif
	vmd = VM_DOMAIN(domain);
	if (vm_domain_allocate(vmd, req, npages)) {
		/*
		 * allocate them from the free page queues.
		 */
		vm_domain_free_lock(vmd);
		m_ret = vm_phys_alloc_contig(domain, npages, low, high,
		    alignment, boundary);
		vm_domain_free_unlock(vmd);
		if (m_ret == NULL) {