Index: sys/kern/kern_intr.c
===================================================================
--- sys/kern/kern_intr.c
+++ sys/kern/kern_intr.c
@@ -189,12 +189,12 @@
 {
 	struct intr_handler *ih;
 	char *last;
-	int missed, space;
+	int missed, space, flags;
 
 	/* Start off with no entropy and just the name of the event. */
 	mtx_assert(&ie->ie_lock, MA_OWNED);
 	strlcpy(ie->ie_fullname, ie->ie_name, sizeof(ie->ie_fullname));
-	ie->ie_hflags = 0;
+	flags = 0;
 	missed = 0;
 	space = 1;
 
@@ -207,8 +207,9 @@
 			space = 0;
 		} else
 			missed++;
-		ie->ie_hflags |= ih->ih_flags;
+		flags |= ih->ih_flags;
 	}
+	ie->ie_hflags = flags;
 
 	/*
 	 * If there is only one handler and its name is too long, just copy in
@@ -1208,6 +1209,7 @@
 	struct thread *td;
 	struct proc *p;
 	int wake, epoch_count;
+	bool needs_epoch;
 
 	td = curthread;
 	p = td->td_proc;
@@ -1242,20 +1244,21 @@
 		 * that the load of ih_need in ithread_execute_handlers()
 		 * is ordered after the load of it_need here.
 		 */
-		if (ie->ie_hflags & IH_NET) {
+		needs_epoch = (ie->ie_hflags & IH_NET) != 0;
+		if (needs_epoch) {
 			epoch_count = 0;
 			NET_EPOCH_ENTER(et);
 		}
 		while (atomic_cmpset_acq_int(&ithd->it_need, 1, 0) != 0) {
 			ithread_execute_handlers(p, ie);
-			if ((ie->ie_hflags & IH_NET) &&
+			if (needs_epoch &&
 			    ++epoch_count >= intr_epoch_batch) {
 				NET_EPOCH_EXIT(et);
 				epoch_count = 0;
 				NET_EPOCH_ENTER(et);
 			}
 		}
-		if (ie->ie_hflags & IH_NET)
+		if (needs_epoch)
 			NET_EPOCH_EXIT(et);
 		WITNESS_WARN(WARN_PANIC, NULL, "suspending ithread");
 		mtx_assert(&Giant, MA_NOTOWNED);
Index: sys/sys/interrupt.h
===================================================================
--- sys/sys/interrupt.h
+++ sys/sys/interrupt.h
@@ -119,7 +119,7 @@
 	void		(*ie_post_filter)(void *);
 	int		(*ie_assign_cpu)(void *, int);
 	int		ie_flags;
-	int		ie_hflags;	/* Cumulative flags of all handlers. */
+	volatile int	ie_hflags;	/* Cumulative flags of all handlers. */
 	int		ie_count;	/* Loop counter. */
 	int		ie_warncnt;	/* Rate-check interrupt storm warns. */
 	struct timeval	ie_warntm;