Index: doc/mm
===================================================================
--- doc/mm	(revision 45ba9cff91f85735ed40588cd0454ae9c2fa673c)
+++ doc/mm	(revision 20d50a15ee7f195ac1e5a2da974bef0722bb9d60)
@@ -2,6 +2,12 @@
 =================
 
-SPARTAN kernel deploys generic interface for 4-level page tables,
-no matter what the real underlying hardware architecture is.
+1. Virtual Address Translation
+
+1.1 Hierarchical 4-level per address space page tables
+
+SPARTAN kernel deploys generic interface for 4-level page tables
+for these architectures: amd64, ia32, mips32 and ppc32. In this
+setting, page tables are hierarchical and are not shared by
+address spaces (i.e. one set of page tables per address space).
 
 
@@ -51,2 +57,11 @@
 left out. TLB-only architectures are to define custom format for software page
 tables.
+
+
+
+1.2 Single global page hash table
+
+Generic page hash table interface is deployed on 64-bit architectures without
+implied hardware support for hierarchical page tables, i.e. ia64 and sparc64.
+There is only one global page hash table in the system shared by all address
+spaces.