2 files changed, 15 insertions, 19 deletions

diff --git a/sys/vm/vm_domainset.c b/sys/vm/vm_domainset.c
index 9fa17da954f7..c25ed0cc2267 100644
--- a/sys/vm/vm_domainset.c
+++ b/sys/vm/vm_domainset.c
@@ -113,7 +113,6 @@ vm_domainset_iter_interleave(struct vm_domainset_iter *di, int *domain)
 	int d;
 
 	d = di->di_offset % di->di_domain->ds_cnt;
-	*di->di_iter = d;
 	*domain = di->di_domain->ds_order[d];
 }
 
@@ -260,9 +259,14 @@ vm_domainset_iter_page_init(struct vm_domainset_iter *di, struct vm_object *obj,
 	 * are immutable and unsynchronized.  Updates can race but pointer
 	 * loads are assumed to be atomic.
 	 */
-	if (obj != NULL && obj->domain.dr_policy != NULL)
+	if (obj != NULL && obj->domain.dr_policy != NULL) {
+		/*
+		 * This write lock protects non-atomic increments of the
+		 * iterator index in vm_domainset_iter_rr().
+		 */
+		VM_OBJECT_ASSERT_WLOCKED(obj);
 		dr = &obj->domain;
-	else
+	} else
 		dr = &curthread->td_domain;
 
 	vm_domainset_iter_init(di, dr->dr_policy, &dr->dr_iter, obj, pindex);
diff --git a/sys/vm/vm_glue.c b/sys/vm/vm_glue.c
index e0f1807a1b32..18d789c59281 100644
--- a/sys/vm/vm_glue.c
+++ b/sys/vm/vm_glue.c
@@ -441,19 +441,16 @@ vm_thread_kstack_arena_release(void *arena, vmem_addr_t addr, vmem_size_t size)
  * Create the kernel stack for a new thread.
  */
 static vm_offset_t
-vm_thread_stack_create(struct domainset *ds, int pages)
+vm_thread_stack_create(struct domainset *ds, int pages, int flags)
 {
 	vm_page_t ma[KSTACK_MAX_PAGES];
 	struct vm_domainset_iter di;
-	int req = VM_ALLOC_NORMAL;
-	vm_object_t obj;
+	int req;
 	vm_offset_t ks;
 	int domain, i;
 
-	obj = vm_thread_kstack_size_to_obj(pages);
-	if (vm_ndomains > 1)
-		obj->domain.dr_policy = ds;
-	vm_domainset_iter_page_init(&di, obj, 0, &domain, &req);
+	vm_domainset_iter_policy_init(&di, ds, &domain, &flags);
+	req = malloc2vm_flags(flags);
 	do {
 		/*
 		 * Get a kernel virtual address for this thread's kstack.
@@ -480,7 +477,7 @@ vm_thread_stack_create(struct domainset *ds, int pages)
 			vm_page_valid(ma[i]);
 		pmap_qenter(ks, ma, pages);
 		return (ks);
-	} while (vm_domainset_iter_page(&di, obj, &domain, NULL) == 0);
+	} while (vm_domainset_iter_policy(&di, &domain) == 0);
 
 	return (0);
 }
@@ -532,15 +529,9 @@ vm_thread_new(struct thread *td, int pages)
 	ks = 0;
 	if (pages == kstack_pages && kstack_cache != NULL)
 		ks = (vm_offset_t)uma_zalloc(kstack_cache, M_NOWAIT);
-
-	/*
-	 * Ensure that kstack objects can draw pages from any memory
-	 * domain.  Otherwise a local memory shortage can block a process
-	 * swap-in.
-	 */
 	if (ks == 0)
 		ks = vm_thread_stack_create(DOMAINSET_PREF(PCPU_GET(domain)),
-		    pages);
+		    pages, M_NOWAIT);
 	if (ks == 0)
 		return (0);
 
@@ -660,7 +651,8 @@ kstack_import(void *arg, void **store, int cnt, int domain, int flags)
 		ds = DOMAINSET_PREF(domain);
 
 	for (i = 0; i < cnt; i++) {
-		store[i] = (void *)vm_thread_stack_create(ds, kstack_pages);
+		store[i] = (void *)vm_thread_stack_create(ds, kstack_pages,
+		    flags);
 		if (store[i] == NULL)
 			break;
 	}