X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=mm%2FKconfig;h=4e9937ac3529ae391762f5071e938f8ac5497077;hb=13e4b57f6a4e23ceb99794a650d777e74831f4a6;hp=69caa9d8674ec3e770956537ce1bd883e15f88d8;hpb=3a9da7655d2d5b7f790a370328cf093440c80496;p=linux-2.6

diff --git a/mm/Kconfig b/mm/Kconfig
index 69caa9d867..4e9937ac35 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -1,10 +1,15 @@
+config SELECT_MEMORY_MODEL
+	def_bool y
+	depends on EXPERIMENTAL || ARCH_SELECT_MEMORY_MODEL
+
 choice
 	prompt "Memory model"
-	default FLATMEM
-	default SPARSEMEM if ARCH_SPARSEMEM_DEFAULT
-	default DISCONTIGMEM if ARCH_DISCONTIGMEM_DEFAULT
+	depends on SELECT_MEMORY_MODEL
+	default DISCONTIGMEM_MANUAL if ARCH_DISCONTIGMEM_DEFAULT
+	default SPARSEMEM_MANUAL if ARCH_SPARSEMEM_DEFAULT
+	default FLATMEM_MANUAL
 
-config FLATMEM
+config FLATMEM_MANUAL
 	bool "Flat Memory"
 	depends on !ARCH_DISCONTIGMEM_ENABLE || ARCH_FLATMEM_ENABLE
 	help
@@ -13,13 +18,96 @@ config FLATMEM
 	  only have one option here: FLATMEM.  This is normal
 	  and a correct option.
 
-	  If unsure, choose this option over any other.
+	  Some users of more advanced features like NUMA and
+	  memory hotplug may have different options here.
+	  DISCONTIGMEM is an more mature, better tested system,
+	  but is incompatible with memory hotplug and may suffer
+	  decreased performance over SPARSEMEM.  If unsure between
+	  "Sparse Memory" and "Discontiguous Memory", choose
+	  "Discontiguous Memory".
 
-config DISCONTIGMEM
+	  If unsure, choose this option (Flat Memory) over any other.
+
+config DISCONTIGMEM_MANUAL
 	bool "Discontigious Memory"
 	depends on ARCH_DISCONTIGMEM_ENABLE
 	help
+	  This option provides enhanced support for discontiguous
+	  memory systems, over FLATMEM.  These systems have holes
+	  in their physical address spaces, and this option provides
+	  more efficient handling of these holes.  However, the vast
+	  majority of hardware has quite flat address spaces, and
+	  can have degraded performance from extra overhead that
+	  this option imposes.
+
+	  Many NUMA configurations will have this as the only option.
+
 	  If unsure, choose "Flat Memory" over this option.
 
+config SPARSEMEM_MANUAL
+	bool "Sparse Memory"
+	depends on ARCH_SPARSEMEM_ENABLE
+	help
+	  This will be the only option for some systems, including
+	  memory hotplug systems.  This is normal.
+
+	  For many other systems, this will be an alternative to
+	  "Discontigious Memory".  This option provides some potential
+	  performance benefits, along with decreased code complexity,
+	  but it is newer, and more experimental.
+
+	  If unsure, choose "Discontiguous Memory" or "Flat Memory"
+	  over this option.
+
 endchoice
 
+config DISCONTIGMEM
+	def_bool y
+	depends on (!SELECT_MEMORY_MODEL && ARCH_DISCONTIGMEM_ENABLE) || DISCONTIGMEM_MANUAL
+
+config SPARSEMEM
+	def_bool y
+	depends on SPARSEMEM_MANUAL
+
+config FLATMEM
+	def_bool y
+	depends on (!DISCONTIGMEM && !SPARSEMEM) || FLATMEM_MANUAL
+
+config FLAT_NODE_MEM_MAP
+	def_bool y
+	depends on !SPARSEMEM
+
+#
+# Both the NUMA code and DISCONTIGMEM use arrays of pg_data_t's
+# to represent different areas of memory.  This variable allows
+# those dependencies to exist individually.
+#
+config NEED_MULTIPLE_NODES
+	def_bool y
+	depends on DISCONTIGMEM || NUMA
+
+config HAVE_MEMORY_PRESENT
+	def_bool y
+	depends on ARCH_HAVE_MEMORY_PRESENT || SPARSEMEM
+
+#
+# SPARSEMEM_EXTREME (which is the default) does some bootmem
+# allocations when memory_present() is called.  If this can not
+# be done on your architecture, select this option.  However,
+# statically allocating the mem_section[] array can potentially
+# consume vast quantities of .bss, so be careful.
+#
+# This option will also potentially produce smaller runtime code
+# with gcc 3.4 and later.
+#
+config SPARSEMEM_STATIC
+	def_bool n
+
+#
+# Architectecture platforms which require a two level mem_section in SPARSEMEM
+# must select this option. This is usually for architecture platforms with
+# an extremely sparse physical address space.
+#
+config SPARSEMEM_EXTREME
+	def_bool y
+	depends on SPARSEMEM && !SPARSEMEM_STATIC