Index: sys/kern/kern_mutex.c
===================================================================
--- sys/kern/kern_mutex.c
+++ sys/kern/kern_mutex.c
@@ -895,6 +895,8 @@
 	doing_lockprof = 1;
 #elif defined(KDTRACE_HOOKS)
 	doing_lockprof = lockstat_enabled;
+#endif
+#ifdef KDTRACE_HOOKS
 	if (__predict_false(doing_lockprof))
 		spin_time -= lockstat_nsecs(&td->td_lock->lock_object);
 #endif