diff --git a/sys/sys/userret.h b/sys/sys/userret.h
index 58f0742e9539..01e43880ea3f 100644
--- a/sys/sys/userret.h
+++ b/sys/sys/userret.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: userret.h,v 1.22 2011/02/25 22:37:12 yamt Exp $	*/
+/*	$NetBSD: userret.h,v 1.23 2011/04/08 10:36:58 yamt Exp $	*/
 
 /*-
  * Copyright (c) 1998, 2000, 2003, 2006, 2008 The NetBSD Foundation, Inc.
@@ -94,6 +94,13 @@ mi_userret(struct lwp *l)
 	if (__predict_false(((l->l_flag & LW_USERRET) | p->p_timerpend) != 0))
 		lwp_userret(l);
 	l->l_kpriority = false;
+	/*
+	 * cpu_set_curpri(prio) is a MD optimized version of:
+	 *
+	 *	kpreempt_disable();
+	 *	curcpu()->ci_schedstate.spc_curpriority = prio;
+	 *	kpreempt_enable();
+	 */
 	cpu_set_curpri(l->l_priority);	/* XXX this needs to die */
 #else
 	ci = l->l_cpu;
diff --git a/sys/uvm/uvm_map.c b/sys/uvm/uvm_map.c
index 6f0fbcc72be3..904f6031e566 100644
--- a/sys/uvm/uvm_map.c
+++ b/sys/uvm/uvm_map.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: uvm_map.c,v 1.295 2011/02/02 15:25:27 chuck Exp $	*/
+/*	$NetBSD: uvm_map.c,v 1.296 2011/04/08 10:38:36 yamt Exp $	*/
 
 /*
  * Copyright (c) 1997 Charles D. Cranor and Washington University.
@@ -66,7 +66,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uvm_map.c,v 1.295 2011/02/02 15:25:27 chuck Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uvm_map.c,v 1.296 2011/04/08 10:38:36 yamt Exp $");
 
 #include "opt_ddb.h"
 #include "opt_uvmhist.h"
@@ -3398,11 +3398,12 @@ uvm_map_willneed(struct vm_map *map, vaddr_t start, vaddr_t end)
 		KASSERT(entry != &map->header);
 		KASSERT(start < entry->end);
 		/*
-		 * XXX IMPLEMENT ME.
-		 * Should invent a "weak" mode for uvm_fault()
-		 * which would only do the PGO_LOCKED pgo_get().
+		 * For now, we handle only the easy but commonly-requested case.
+		 * ie. start prefetching of backing uobj pages.
 		 *
-		 * for now, we handle only the easy but common case.
+		 * XXX It might be useful to pmap_enter() the already-in-core
+		 * pages by inventing a "weak" mode for uvm_fault() which would
+		 * only do the PGO_LOCKED pgo_get().
 		 */
 		if (UVM_ET_ISOBJ(entry) && amap == NULL && uobj != NULL) {
 			off_t offset;