diff --git a/sys/kern/kern_malloc.c b/sys/kern/kern_malloc.c
index 3790a98..f2fe95f 100644
--- a/sys/kern/kern_malloc.c
+++ b/sys/kern/kern_malloc.c
@@ -240,6 +240,22 @@ SYSCTL_INT(_debug_malloc, OID_AUTO, failure_count, CTLFLAG_RD,
     &malloc_failure_count, 0, "Number of imposed M_NOWAIT malloc failures");
 #endif
 
+static void
+add_kmem_map_size_sysctl(void)
+{
+
+	if (sizeof(kmem_map->size) == sizeof(int))
+		SYSCTL_ADD_UINT(NULL,  SYSCTL_STATIC_CHILDREN(_vm), OID_AUTO,
+		    "kmem_map_size", CTLFLAG_RD, &kmem_map->size, 0,
+		    "Current size of kmem_map");
+	else
+		SYSCTL_ADD_ULONG(NULL,  SYSCTL_STATIC_CHILDREN(_vm), OID_AUTO,
+		    "kmem_map_size", CTLFLAG_RD, &kmem_map->size,
+		    "Current size of kmem_map");
+}
+SYSINIT(add_kmem_map_size_sysctl, SI_SUB_RUN_SCHEDULER, SI_ORDER_MIDDLE,
+    add_kmem_map_size_sysctl, NULL);
+
 /*
  * malloc(9) uma zone separation -- sub-page buffer overruns in one
  * malloc type will affect only a subset of other malloc types.