There is no need to have an extra global variable storing the MMU page
size.

Index: sys/kern/kern_sysctl.c
===================================================================
RCS file: /OpenBSD/src/sys/kern/kern_sysctl.c,v
retrieving revision 1.411
diff -u -p -r1.411 kern_sysctl.c
--- sys/kern/kern_sysctl.c	22 Jan 2023 12:05:44 -0000	1.411
+++ sys/kern/kern_sysctl.c	25 Mar 2024 19:44:12 -0000
@@ -664,13 +664,12 @@ int hw_power = 1;
 
 /* morally const values reported by sysctl_bounded_arr */
 static int byte_order = BYTE_ORDER;
-static int page_size = PAGE_SIZE;
 
 const struct sysctl_bounded_args hw_vars[] = {
 	{HW_NCPU, &ncpus, SYSCTL_INT_READONLY},
 	{HW_NCPUFOUND, &ncpusfound, SYSCTL_INT_READONLY},
 	{HW_BYTEORDER, &byte_order, SYSCTL_INT_READONLY},
-	{HW_PAGESIZE, &page_size, SYSCTL_INT_READONLY},
+	{HW_PAGESIZE, &uvmexp.pagesize, SYSCTL_INT_READONLY},
 	{HW_DISKCOUNT, &disk_count, SYSCTL_INT_READONLY},
 	{HW_POWER, &hw_power, SYSCTL_INT_READONLY},
 };