Index: sys/vm/vm_page.c
===================================================================
--- sys/vm/vm_page.c
+++ sys/vm/vm_page.c
@@ -1633,6 +1633,7 @@
 	 * vm_page_cache().
 	 */
 	mtx_lock_flags(&vm_page_queue_free_mtx, MTX_RECURSE);
+	m = NULL;
 	if (vm_cnt.v_free_count + vm_cnt.v_cache_count > vm_cnt.v_free_reserved ||
 	    (req_class == VM_ALLOC_SYSTEM &&
 	    vm_cnt.v_free_count + vm_cnt.v_cache_count > vm_cnt.v_interrupt_free_min) ||
@@ -1677,7 +1678,19 @@
 			}
 #endif
 		}
-	} else {
+	}
+
+	/*
+	 * Can't allocate or attempted to and couldn't allocate a page
+	 * given the current VM policy.  Give up.
+	 *
+	 * Note - yes, this is one of the current shortcomings of the
+	 * VM domain design - there's a global set of vm_cnt counters,
+	 * and it's quite possible things will get unhappy with this.
+	 * However without it'll kernel panic below - the code didn't
+	 * check m == NULL here and would continue.
+	 */
+	if (m == NULL) {
 		/*
 		 * Not allocatable, give up.
 		 */