diff --git a/sys/kern/subr_intr.c b/sys/kern/subr_intr.c
--- a/sys/kern/subr_intr.c
+++ b/sys/kern/subr_intr.c
@@ -152,8 +152,7 @@
 /* Data for statistics reporting. */
 static u_long *intrcnt;
 static char *intrnames;
-static size_t sintrcnt;
-static size_t sintrnames;
+static u_int intrcnt_index;
 static int nintrcnt;
 static bitstr_t *intrcnt_bitmap;
 
@@ -188,8 +187,6 @@
 	    M_WAITOK | M_ZERO);
 	intrnames = mallocarray(nintrcnt, INTRNAME_LEN, M_INTRNG,
 	    M_WAITOK | M_ZERO);
-	sintrcnt = nintrcnt * sizeof(u_long);
-	sintrnames = nintrcnt * INTRNAME_LEN;
 
 	/* Allocate the bitmap tracking counter allocations. */
 	intrcnt_bitmap = bit_alloc(nintrcnt, M_INTRNG, M_WAITOK | M_ZERO);
@@ -283,6 +280,8 @@
 	if (index == -1)
 		panic("Failed to allocate 2 counters. Array exhausted?");
 	bit_nset(intrcnt_bitmap, index, index + 1);
+	if (index >= intrcnt_index)
+		intrcnt_index = index + 2;
 	isrc->isrc_index = index;
 	isrc->isrc_count = &intrcnt[index];
 	isrc_update_name(isrc, NULL);
@@ -325,6 +324,8 @@
 		panic("Failed to allocate %d counters. Array exhausted?",
 		    MAXCPU);
 	bit_nset(intrcnt_bitmap, index, index + MAXCPU - 1);
+	if (index >= intrcnt_index)
+		intrcnt_index = index + MAXCPU;
 	for (i = 0; i < MAXCPU; i++) {
 		snprintf(str, INTRNAME_LEN, "cpu%d:%s", i, name);
 		intrcnt_setname(str, index + i);
@@ -1783,7 +1784,8 @@
 static int
 sysctl_intrnames(SYSCTL_HANDLER_ARGS)
 {
-	return (sysctl_handle_opaque(oidp, intrnames, sintrnames, req));
+	return (sysctl_handle_opaque(oidp, intrnames,
+	    intrcnt_index * INTRNAME_LEN, req));
 }
 
 SYSCTL_PROC(_hw, OID_AUTO, intrnames,
@@ -1801,18 +1803,22 @@
 
 	if (req->flags & SCTL_MASK32) {
 		if (!req->oldptr)
-			return (sysctl_handle_opaque(oidp, NULL, sintrcnt / 2, req));
-		intrcnt32 = malloc(sintrcnt / 2, M_TEMP, M_NOWAIT);
+			return (sysctl_handle_opaque(oidp, NULL,
+			    intrcnt_index * sizeof(uint32_t), req));
+		intrcnt32 = malloc(intrcnt_index * sizeof(uint32_t), M_TEMP,
+		    M_NOWAIT);
 		if (intrcnt32 == NULL)
 			return (ENOMEM);
-		for (i = 0; i < sintrcnt / sizeof (u_long); i++)
+		for (i = 0; i < intrcnt_index; i++)
 			intrcnt32[i] = intrcnt[i];
-		error = sysctl_handle_opaque(oidp, intrcnt32, sintrcnt / 2, req);
+		error = sysctl_handle_opaque(oidp, intrcnt32,
+		    intrcnt_index * sizeof(uint32_t), req);
 		free(intrcnt32, M_TEMP);
 		return (error);
 	}
 #endif
-	return (sysctl_handle_opaque(oidp, intrcnt, sintrcnt, req));
+	return (sysctl_handle_opaque(oidp, intrcnt,
+	    intrcnt_index * sizeof(u_long), req));
 }
 
 SYSCTL_PROC(_hw, OID_AUTO, intrcnt,
@@ -1826,19 +1832,11 @@
  */
 DB_SHOW_COMMAND_FLAGS(intrcnt, db_show_intrcnt, DB_CMD_MEMSAFE)
 {
-	u_long *i;
-	char *cp;
-	u_int j;
+	u_int i;
 
-	cp = intrnames;
-	j = 0;
-	for (i = intrcnt; j < (sintrcnt / sizeof(u_long)) && !db_pager_quit;
-	    i++, j++) {
-		if (*cp == '\0')
-			break;
-		if (*i != 0)
-			db_printf("%s\t%lu\n", cp, *i);
-		cp += strlen(cp) + 1;
-	}
+	for (i = 0; i < intrcnt_index && !db_pager_quit; ++i)
+		if (intrcnt[i] != 0)
+			db_printf("%s\t%lu\n", intrnames + i * INTRNAME_LEN,
+			    intrcnt[i]);
 }
 #endif
diff --git a/sys/powerpc/powerpc/intr_machdep.c b/sys/powerpc/powerpc/intr_machdep.c
--- a/sys/powerpc/powerpc/intr_machdep.c
+++ b/sys/powerpc/powerpc/intr_machdep.c
@@ -117,7 +117,6 @@
 	int	base;
 };
 
-static u_int intrcnt_index = 0;
 static struct mtx intr_table_lock;
 static struct powerpc_intr **powerpc_intrs;
 static struct pic piclist[MAX_PICS];
@@ -133,8 +132,7 @@
 #define	INTRNAME_LEN	(MAXCOMLEN + 1)
 static u_long *intrcnt;
 static char *intrnames;
-static size_t sintrcnt = sizeof(intrcnt);
-static size_t sintrnames = sizeof(intrnames);
+static u_int intrcnt_index;
 static int nintrcnt;
 
 /*
@@ -183,8 +181,6 @@
 	    M_ZERO);
 	intrnames = mallocarray(nintrcnt, INTRNAME_LEN, M_INTR, M_WAITOK |
 	    M_ZERO);
-	sintrcnt = nintrcnt * sizeof(u_long);
-	sintrnames = nintrcnt * INTRNAME_LEN;
 
 	intrcnt_setname("???", 0);
 	intrcnt_index = 1;
@@ -703,7 +699,8 @@
 static int
 sysctl_intrnames(SYSCTL_HANDLER_ARGS)
 {
-	return (sysctl_handle_opaque(oidp, intrnames, sintrnames, req));
+	return (sysctl_handle_opaque(oidp, intrnames,
+	    intrcnt_index * INTRNAME_LEN, req));
 }
 
 SYSCTL_PROC(_hw, OID_AUTO, intrnames,
@@ -721,18 +718,22 @@
 
 	if (req->flags & SCTL_MASK32) {
 		if (!req->oldptr)
-			return (sysctl_handle_opaque(oidp, NULL, sintrcnt / 2, req));
-		intrcnt32 = malloc(sintrcnt / 2, M_TEMP, M_NOWAIT);
+			return (sysctl_handle_opaque(oidp, NULL,
+			    intrcnt_index * sizeof(uint32_t), req));
+		intrcnt32 = malloc(intrcnt_index * sizeof(uint32_t), M_TEMP,
+		    M_NOWAIT);
 		if (intrcnt32 == NULL)
 			return (ENOMEM);
-		for (i = 0; i < sintrcnt / sizeof (u_long); i++)
+		for (i = 0; i < intrcnt_index; i++)
 			intrcnt32[i] = intrcnt[i];
-		error = sysctl_handle_opaque(oidp, intrcnt32, sintrcnt / 2, req);
+		error = sysctl_handle_opaque(oidp, intrcnt32,
+		    intrcnt_index * sizeof(uint32_t), req);
 		free(intrcnt32, M_TEMP);
 		return (error);
 	}
 #endif
-	return (sysctl_handle_opaque(oidp, intrcnt, sintrcnt, req));
+	return (sysctl_handle_opaque(oidp, intrcnt,
+	    intrcnt_index * sizeof(u_long), req));
 }
 
 SYSCTL_PROC(_hw, OID_AUTO, intrcnt,
@@ -746,19 +747,11 @@
  */
 DB_SHOW_COMMAND_FLAGS(intrcnt, db_show_intrcnt, DB_CMD_MEMSAFE)
 {
-	u_long *i;
-	char *cp;
-	u_int j;
-
-	cp = intrnames;
-	j = 0;
-	for (i = intrcnt; j < (sintrcnt / sizeof(u_long)) && !db_pager_quit;
-	    i++, j++) {
-		if (*cp == '\0')
-			break;
-		if (*i != 0)
-			db_printf("%s\t%lu\n", cp, *i);
-		cp += strlen(cp) + 1;
-	}
+	u_int i;
+
+	for (i = 0; i < intrcnt_index && !db_pager_quit; ++i)
+		if (intrcnt[i] != 0)
+			db_printf("%s\t%lu\n", intrnames + i * INTRNAME_LEN,
+			    intrcnt[i]);
 }
 #endif
diff --git a/sys/x86/x86/intr_machdep.c b/sys/x86/x86/intr_machdep.c
--- a/sys/x86/x86/intr_machdep.c
+++ b/sys/x86/x86/intr_machdep.c
@@ -76,7 +76,6 @@
 
 typedef void (*mask_fn)(void *);
 
-static int intrcnt_index;
 static struct intsrc **interrupt_sources;
 #ifdef SMP
 static struct intsrc **interrupt_sorted;
@@ -98,8 +97,7 @@
 #define	INTRNAME_LEN	(MAXCOMLEN + 1)
 static u_long *intrcnt;
 static char *intrnames;
-static size_t sintrcnt = sizeof(intrcnt);
-static size_t sintrnames = sizeof(intrnames);
+static u_int intrcnt_index;
 static int nintrcnt;
 
 static MALLOC_DEFINE(M_INTR, "intr", "Interrupt Sources");
@@ -192,8 +190,6 @@
 	    M_ZERO);
 	intrnames = mallocarray(nintrcnt, INTRNAME_LEN, M_INTR, M_WAITOK |
 	    M_ZERO);
-	sintrcnt = nintrcnt * sizeof(u_long);
-	sintrnames = nintrcnt * INTRNAME_LEN;
 
 	intrcnt_setname("???", 0);
 	intrcnt_index = 1;
@@ -854,7 +850,8 @@
 static int
 sysctl_intrnames(SYSCTL_HANDLER_ARGS)
 {
-	return (sysctl_handle_opaque(oidp, intrnames, sintrnames, req));
+	return (sysctl_handle_opaque(oidp, intrnames,
+	    intrcnt_index * INTRNAME_LEN, req));
 }
 
 SYSCTL_PROC(_hw, OID_AUTO, intrnames,
@@ -872,18 +869,22 @@
 
 	if (req->flags & SCTL_MASK32) {
 		if (!req->oldptr)
-			return (sysctl_handle_opaque(oidp, NULL, sintrcnt / 2, req));
-		intrcnt32 = malloc(sintrcnt / 2, M_TEMP, M_NOWAIT);
+			return (sysctl_handle_opaque(oidp, NULL,
+			    intrcnt_index * sizeof(uint32_t), req));
+		intrcnt32 = malloc(intrcnt_index * sizeof(uint32_t), M_TEMP,
+		    M_NOWAIT);
 		if (intrcnt32 == NULL)
 			return (ENOMEM);
-		for (i = 0; i < sintrcnt / sizeof (u_long); i++)
+		for (i = 0; i < intrcnt_index; i++)
 			intrcnt32[i] = intrcnt[i];
-		error = sysctl_handle_opaque(oidp, intrcnt32, sintrcnt / 2, req);
+		error = sysctl_handle_opaque(oidp, intrcnt32,
+		    intrcnt_index * sizeof(uint32_t), req);
 		free(intrcnt32, M_TEMP);
 		return (error);
 	}
 #endif
-	return (sysctl_handle_opaque(oidp, intrcnt, sintrcnt, req));
+	return (sysctl_handle_opaque(oidp, intrcnt,
+	    intrcnt_index * sizeof(u_long), req));
 }
 
 SYSCTL_PROC(_hw, OID_AUTO, intrcnt,
@@ -897,19 +898,11 @@
  */
 DB_SHOW_COMMAND_FLAGS(intrcnt, db_show_intrcnt, DB_CMD_MEMSAFE)
 {
-	u_long *i;
-	char *cp;
-	u_int j;
-
-	cp = intrnames;
-	j = 0;
-	for (i = intrcnt; j < (sintrcnt / sizeof(u_long)) && !db_pager_quit;
-	    i++, j++) {
-		if (*cp == '\0')
-			break;
-		if (*i != 0)
-			db_printf("%s\t%lu\n", cp, *i);
-		cp += strlen(cp) + 1;
-	}
+	u_int i;
+
+	for (i = 0; i < intrcnt_index && !db_pager_quit; ++i)
+		if (intrcnt[i] != 0)
+			db_printf("%s\t%lu\n", intrnames + i * INTRNAME_LEN,
+			    intrcnt[i]);
 }
 #endif