diff --git a/sys/kern/kern_rwlock.c b/sys/kern/kern_rwlock.c
index 370d0d6..555a9db 100644
--- a/sys/kern/kern_rwlock.c
+++ b/sys/kern/kern_rwlock.c
@@ -378,7 +378,8 @@ __rw_rlock(volatile uintptr_t *c, const char *file, int line)
 	WITNESS_CHECKORDER(&rw->lock_object, LOP_NEWORDER, file, line, NULL);
 
 #ifdef KDTRACE_HOOKS
-	all_time -= lockstat_nsecs(&rw->lock_object);
+	if (__predict_false(lockstat_enabled))
+		all_time -= lockstat_nsecs(&rw->lock_object);
 	state = rw->rw_lock;
 #endif
 	for (;;) {
@@ -544,7 +545,8 @@ __rw_rlock(volatile uintptr_t *c, const char *file, int line)
 			    __func__, rw);
 	}
 #ifdef KDTRACE_HOOKS
-	all_time += lockstat_nsecs(&rw->lock_object);
+	if (__predict_false(lockstat_enabled))
+		all_time += lockstat_nsecs(&rw->lock_object);
 	if (sleep_time)
 		LOCKSTAT_RECORD4(rw__block, rw, sleep_time,
 		    LOCKSTAT_READER, (state & RW_LOCK_READ) == 0,