diff --git a/sys/kern/kern_lock.c b/sys/kern/kern_lock.c
index dcacd5c431ef..875b06178da5 100644
--- a/sys/kern/kern_lock.c
+++ b/sys/kern/kern_lock.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: kern_lock.c,v 1.99 2006/09/07 02:06:47 ad Exp $	*/
+/*	$NetBSD: kern_lock.c,v 1.100 2006/09/30 11:59:37 yamt Exp $	*/
 
 /*-
  * Copyright (c) 1999, 2000 The NetBSD Foundation, Inc.
@@ -76,7 +76,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_lock.c,v 1.99 2006/09/07 02:06:47 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_lock.c,v 1.100 2006/09/30 11:59:37 yamt Exp $");
 
 #include "opt_multiprocessor.h"
 #include "opt_lockdebug.h"
@@ -1556,8 +1556,18 @@ _kernel_lock_acquire_count(int hold_count)
 void
 _kernel_lock_assert_locked()
 {
+
+	KDASSERT(curcpu()->ci_data.cpu_biglock_count > 0);
 	simple_lock_assert_locked(&kernel_lock, "kernel_lock");
 }
+
+void
+_kernel_lock_assert_unlocked()
+{
+
+	KDASSERT(curcpu()->ci_data.cpu_biglock_count == 0);
+	simple_lock_assert_unlocked(&kernel_lock, "kernel_lock");
+}
 #endif
 
 int
diff --git a/sys/sys/systm.h b/sys/sys/systm.h
index 89e9a4a75e10..0f320c76fc61 100644
--- a/sys/sys/systm.h
+++ b/sys/sys/systm.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: systm.h,v 1.189 2006/09/24 06:51:39 dogcow Exp $	*/
+/*	$NetBSD: systm.h,v 1.190 2006/09/30 11:59:37 yamt Exp $	*/
 
 /*-
  * Copyright (c) 1982, 1988, 1991, 1993
@@ -498,9 +498,12 @@ void	_kernel_lock_acquire_count(int);
 
 #if defined(MULTIPROCESSOR) && defined(DEBUG)
 #define	KERNEL_LOCK_ASSERT_LOCKED()	_kernel_lock_assert_locked()
+#define	KERNEL_LOCK_ASSERT_UNLOCKED()	_kernel_lock_assert_unlocked()
 void _kernel_lock_assert_locked(void);
+void _kernel_lock_assert_unlocked(void);
 #else
 #define	KERNEL_LOCK_ASSERT_LOCKED()	/* nothing */
+#define	KERNEL_LOCK_ASSERT_UNLOCKED()	/* nothing */
 #endif
 
 #endif	/* !_SYS_SYSTM_H_ */