Index: sys/vm/uma_core.c
===================================================================
--- sys/vm/uma_core.c
+++ sys/vm/uma_core.c
@@ -3733,7 +3733,7 @@
 		stripe = howmany(max, vm_ndomains);
 #endif
 		dom = &keg->uk_domain[slab->us_domain];
-		while (slab->us_freecount && i < max) { 
+		do {
 			bucket[i++] = slab_alloc_item(keg, slab);
 			if (dom->ud_free_items <= keg->uk_reserve)
 				break;
@@ -3750,8 +3750,13 @@
 			    vm_ndomains > 1 && --stripe == 0)
 				break;
 #endif
-		}
+		} while (slab->us_freecount != 0 && i < max);
 		KEG_UNLOCK(keg, slab->us_domain);
+
+		/* Don't deplete reserves more than necessary. */
+		if ((flags & M_USE_RESERVE) != 0)
+			break;
+
 		/* Don't block if we allocated any successfully. */
 		flags &= ~M_WAITOK;
 		flags |= M_NOWAIT;