Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/Documentation/vm/index.rst b/Documentation/vm/index.rst
index c4ded22..e8d943b 100644
--- a/Documentation/vm/index.rst
+++ b/Documentation/vm/index.rst
@@ -2,7 +2,9 @@
 Linux Memory Management Documentation
 =====================================
 
-This is a collection of documents about Linux memory management (mm) subsystem.
+This is a collection of documents about the Linux memory management (mm)
+subsystem.  If you are looking for advice on simply allocating memory,
+see the :ref:`memory_allocation`.
 
 User guides for MM features
 ===========================
@@ -35,6 +37,7 @@
    hwpoison
    hugetlbfs_reserv
    ksm
+   memory-model
    mmu_notifier
    numa
    overcommit-accounting