diff --git a/docs/develop/kernel/VM_Locking b/docs/develop/kernel/VM_Locking
index db2db6073f..02d58bdb5b 100644
--- a/docs/develop/kernel/VM_Locking
+++ b/docs/develop/kernel/VM_Locking
@@ -23,6 +23,7 @@ vm_area:
 		mappings: guarded by the global sMappingLock (currently a spinlock)
 		address_space_next: vm_address_space::sem
 		hash_next: sAreaHashLock
+		cache: guarded by vm_area_get_locked_cache()/sAreaCacheLock
 		cache_next|prev: cache_ref::lock
 
 vm_cache_ref:
diff --git a/docs/develop/kernel/VM_TODOs b/docs/develop/kernel/VM_TODOs
new file mode 100644
index 0000000000..60472f6723
--- /dev/null
+++ b/docs/develop/kernel/VM_TODOs
@@ -0,0 +1,2 @@
+- unmap the page of all areas from the cache when a newly added page shadows one
+  in a deeper cache