[PATCH/RFC 1/8] numa - Migrate-on-Fault - add Kconfig option

Migrate-on-fault - add migrate on fault Kconfig option

Add a "MIGRATE_ON_FAULT" Kconfig suboption to "MIGRATION" to
separately enable/disable MIGRATE_ON_FAULT handling.

Signed-off-by: Lee Schermerhorn <[email protected]>

 mm/Kconfig |   12 ++++++++++++
 1 file changed, 12 insertions(+)

Index: linux-2.6.36-mmotm-101103-1217/mm/Kconfig
===================================================================
--- linux-2.6.36-mmotm-101103-1217.orig/mm/Kconfig
+++ linux-2.6.36-mmotm-101103-1217/mm/Kconfig
@@ -198,6 +198,18 @@ config MIGRATION
 	  pages as migration can relocate pages to satisfy a huge page
 	  allocation instead of reclaiming.
 
+# I really want to "select SWAP" here, but that resulted in a circular
+# dependency with "HIBERNATION" back in 28-rc4[-mm*]
+config MIGRATE_ON_FAULT
+	bool "Migrate unmapped page on fault"
+	depends on MIGRATION
+	depends on SWAP
+	help
+	  Allows "misplaced" pages found in a page cache at fault time to be
+	  migrated to the node specified by the applicable policy when the
+	  page is not currently mapped by any tasks.  This allows a task to
+	  pull unmapped pages closer to itself when enabled for that task.
+
 config PHYS_ADDR_T_64BIT
 	def_bool 64BIT || ARCH_PHYS_ADDR_T_64BIT