Index: kern_timeout.c
===================================================================
--- kern_timeout.c	(revision 255636)
+++ kern_timeout.c	(working copy)
@@ -597,11 +597,13 @@ softclock_call_cc(struct callout *c, struct callou
 #endif
     int direct)
 {
+	struct rm_priotracker tracker;
 	void (*c_func)(void *);
 	void *c_arg;
 	struct lock_class *class;
 	struct lock_object *c_lock;
-	int c_flags, sharedlock;
+	uintptr_t sharedlock;
+	int c_flags;
 #ifdef SMP
 	struct callout_cpu *new_cc;
 	void (*new_func)(void *);
@@ -620,7 +622,13 @@ softclock_call_cc(struct callout *c, struct callou
 	    (CALLOUT_PENDING | CALLOUT_ACTIVE),
 	    ("softclock_call_cc: pend|act %p %x", c, c->c_flags));
 	class = (c->c_lock != NULL) ? LOCK_CLASS(c->c_lock) : NULL;
-	sharedlock = (c->c_flags & CALLOUT_SHAREDLOCK) ? 0 : 1;
+	sharedlock = 0;
+	if (c->c_flags & CALLOUT_SHAREDLOCK) {
+		if (class == &lock_class_rm)
+			sharedlock = (uintptr_t)&tracker;
+		else
+			sharedlock = 1;
+	}
 	c_lock = c->c_lock;
 	c_func = c->c_func;
 	c_arg = c->c_arg;