Index: sys/kern/kern_timeout.c
===================================================================
--- sys/kern/kern_timeout.c	(revision 215415)
+++ sys/kern/kern_timeout.c	(working copy)
@@ -581,8 +581,8 @@
  * callout_deactivate() - marks the callout as having been serviced
  */
 int
-callout_reset_on(struct callout *c, int to_ticks, void (*ftn)(void *),
-    void *arg, int cpu)
+_callout_reset_on(struct callout *c, int to_ticks, void (*ftn)(void *),
+    void *arg, int cpu, int tracing)
 {
 	struct callout_cpu *cc;
 	int cancelled = 0;
@@ -608,6 +608,7 @@
 			 * Someone has called callout_drain to kill this
 			 * callout.  Don't reschedule.
 			 */
+			if (tracing)
 			CTR4(KTR_CALLOUT, "%s %p func %p arg %p",
 			    cancelled ? "cancelled" : "failed to cancel",
 			    c, c->c_func, c->c_arg);
@@ -644,6 +645,7 @@
 	c->c_time = cc->cc_ticks + to_ticks;
 	TAILQ_INSERT_TAIL(&cc->cc_callwheel[c->c_time & callwheelmask], 
 			  c, c_links.tqe);
+	if (tracing)
 	CTR5(KTR_CALLOUT, "%sscheduled %p func %p arg %p in %d",
 	    cancelled ? "re" : "", c, c->c_func, c->c_arg, to_ticks);
 	CC_UNLOCK(cc);
@@ -667,9 +669,10 @@
 }
 
 int
-_callout_stop_safe(c, safe)
+_callout_stop_safe(c, safe, tracing)
 	struct	callout *c;
 	int	safe;
+	int	tracing;
 {
 	struct callout_cpu *cc;
 	struct lock_class *class;
@@ -706,6 +709,7 @@
 		 * callout, then we can't stop it, so just bail.
 		 */
 		if (cc->cc_curr != c) {
+			if (tracing)
 			CTR3(KTR_CALLOUT, "failed to stop %p func %p arg %p",
 			    c, c->c_func, c->c_arg);
 			CC_UNLOCK(cc);
@@ -768,13 +772,15 @@
 			 * softclock().
 			 */
 			cc->cc_cancel = 1;
+			if (tracing)
 			CTR3(KTR_CALLOUT, "cancelled %p func %p arg %p",
 			    c, c->c_func, c->c_arg);
 			CC_UNLOCK(cc);
 			KASSERT(!sq_locked, ("sleepqueue chain locked"));
 			return (1);
 		}
-		CTR3(KTR_CALLOUT, "failed to stop %p func %p arg %p",
+		if (tracing)
+		CTR3(KTR_CALLOUT, "2failed to stop %p func %p arg %p",
 		    c, c->c_func, c->c_arg);
 		CC_UNLOCK(cc);
 		KASSERT(!sq_locked, ("sleepqueue chain still locked"));
@@ -791,6 +797,7 @@
 	TAILQ_REMOVE(&cc->cc_callwheel[c->c_time & callwheelmask], c,
 	    c_links.tqe);
 
+	if (tracing)
 	CTR3(KTR_CALLOUT, "cancelled %p func %p arg %p",
 	    c, c->c_func, c->c_arg);
 
Index: sys/kern/kern_event.c
===================================================================
--- sys/kern/kern_event.c	(revision 215415)
+++ sys/kern/kern_event.c	(working copy)
@@ -519,8 +519,8 @@
 
 	if ((kn->kn_flags & EV_ONESHOT) != EV_ONESHOT) {
 		calloutp = (struct callout *)kn->kn_hook;
-		callout_reset_curcpu(calloutp, timertoticks(kn->kn_sdata),
-		    filt_timerexpire, kn);
+		_callout_reset_on(calloutp, timertoticks(kn->kn_sdata),
+		    filt_timerexpire, kn, calloutp->c_cpu, 1);
 	}
 }
 
@@ -545,8 +545,8 @@
 	calloutp = malloc(sizeof(*calloutp), M_KQUEUE, M_WAITOK);
 	callout_init(calloutp, CALLOUT_MPSAFE);
 	kn->kn_hook = calloutp;
-	callout_reset_curcpu(calloutp, timertoticks(kn->kn_sdata),
-	    filt_timerexpire, kn);
+	_callout_reset_on(calloutp, timertoticks(kn->kn_sdata),
+	    filt_timerexpire, kn, calloutp->c_cpu, 1);
 
 	return (0);
 }
@@ -558,7 +558,7 @@
 	struct callout *calloutp;
 
 	calloutp = (struct callout *)kn->kn_hook;
-	callout_drain(calloutp);
+	_callout_stop_safe(calloutp, 1, 1);
 	free(calloutp, M_KQUEUE);
 	atomic_add_int(&kq_ncallouts, -1);
 	kn->kn_status |= KN_DETACHED;	/* knlist_remove usually clears it */
Index: sys/sys/callout.h
===================================================================
--- sys/sys/callout.h	(revision 215415)
+++ sys/sys/callout.h	(working copy)
@@ -74,7 +74,7 @@
 
 #define	callout_active(c)	((c)->c_flags & CALLOUT_ACTIVE)
 #define	callout_deactivate(c)	((c)->c_flags &= ~CALLOUT_ACTIVE)
-#define	callout_drain(c)	_callout_stop_safe(c, 1)
+#define	callout_drain(c)	_callout_stop_safe(c, 1, 0)
 void	callout_init(struct callout *, int);
 void	_callout_init_lock(struct callout *, struct lock_object *, int);
 #define	callout_init_mtx(c, mtx, flags)					\
@@ -84,7 +84,10 @@
 	_callout_init_lock((c), ((rw) != NULL) ? &(rw)->lock_object :	\
 	   NULL, (flags))
 #define	callout_pending(c)	((c)->c_flags & CALLOUT_PENDING)
-int	callout_reset_on(struct callout *, int, void (*)(void *), void *, int);
+int	_callout_reset_on(struct callout *, int, void (*)(void *), void *, int,
+	int);
+#define	callout_reset_on(c, on_tick, fn, arg, cpu)			\
+	_callout_reset_on((c), (on_tick), (fn), (arg), (cpu), 0)
 #define	callout_reset(c, on_tick, fn, arg)				\
     callout_reset_on((c), (on_tick), (fn), (arg), (c)->c_cpu)
 #define	callout_reset_curcpu(c, on_tick, fn, arg)			\
@@ -93,8 +96,8 @@
 int	callout_schedule_on(struct callout *, int, int);
 #define	callout_schedule_curcpu(c, on_tick)				\
     callout_schedule_on((c), (on_tick), PCPU_GET(cpuid))
-#define	callout_stop(c)		_callout_stop_safe(c, 0)
-int	_callout_stop_safe(struct callout *, int);
+#define	callout_stop(c)		_callout_stop_safe(c, 0, 0)
+int	_callout_stop_safe(struct callout *, int, int);
 void	callout_tick(void);