Index: sys/vm/uma_core.c
===================================================================
--- sys/vm/uma_core.c
+++ sys/vm/uma_core.c
@@ -146,7 +146,11 @@
 
 /* kmem soft limit. */
 static unsigned long uma_kmem_limit = LONG_MAX;
-static volatile unsigned long uma_kmem_total;
+SYSCTL_ULONG(_vm, OID_AUTO, uma_kmem_limit, CTLFLAG_RD, &uma_kmem_limit, 0,
+    "UMA kernel memory soft limit");
+static unsigned long uma_kmem_total;
+SYSCTL_ULONG(_vm, OID_AUTO, uma_kmem_total, CTLFLAG_RD, &uma_kmem_total, 0,
+    "UMA kernel memory usage");
 
 /* Is the VM done starting up? */
 static enum { BOOT_COLD = 0, BOOT_STRAPPED, BOOT_PAGEALLOC, BOOT_BUCKETS,
@@ -3806,14 +3810,14 @@
 uma_size(void)
 {
 
-	return (uma_kmem_total);
+	return (atomic_load_long(&uma_kmem_total));
 }
 
 long
 uma_avail(void)
 {
 
-	return (uma_kmem_limit - uma_kmem_total);
+	return (uma_kmem_limit - uma_size());
 }
 
 void