Index: sys/net/pktqueue.c
===================================================================
RCS file: /cvsroot/src/sys/net/pktqueue.c,v
retrieving revision 1.12
diff -u -p -r1.12 pktqueue.c
--- sys/net/pktqueue.c	11 Sep 2020 14:29:00 -0000	1.12
+++ sys/net/pktqueue.c	24 Mar 2021 07:54:47 -0000
@@ -52,21 +52,19 @@ __KERNEL_RCSID(0, "$NetBSD: pktqueue.c,v
 
 #include <net/pktqueue.h>
 
-/*
- * WARNING: update this if struct pktqueue changes.
- */
-#define	PKTQ_CLPAD	\
-    MAX(COHERENCY_UNIT, COHERENCY_UNIT - sizeof(kmutex_t) - sizeof(u_int))
-
 struct pktqueue {
 	/*
 	 * The lock used for a barrier mechanism.  The barrier counter,
 	 * as well as the drop counter, are managed atomically though.
 	 * Ensure this group is in a separate cache line.
 	 */
-	kmutex_t	pq_lock;
-	volatile u_int	pq_barrier;
-	uint8_t		_pad[PKTQ_CLPAD];
+	union {
+		struct {
+			kmutex_t	pq_lock;
+			volatile u_int	pq_barrier;
+		};
+		uint8_t		_pad[COHERENCY_UNIT];
+	};
 
 	/* The size of the queue, counters and the interrupt handler. */
 	u_int		pq_maxlen;