PAGEFLAGS_EXTENDED and separate page flags for Head and Tail

[linux-2.6-omap-h63xx.git] / mm / Kconfig

diff --git a/mm/Kconfig b/mm/Kconfig
index 0016ebd4dcbac755450579197d317738727816a8..3aa819d628c112cc185f9545c7ae5e3fb8a5c310 100644 (file)
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -143,6 +143,18 @@ config MEMORY_HOTREMOVE
        depends on MEMORY_HOTPLUG && ARCH_ENABLE_MEMORY_HOTREMOVE
        depends on MIGRATION
 
+#
+# If we have space for more page flags then we can enable additional
+# optimizations and functionality.
+#
+# Regular Sparsemem takes page flag bits for the sectionid if it does not
+# use a virtual memmap. Disable extended page flags for 32 bit platforms
+# that require the use of a sectionid in the page flags.
+#
+config PAGEFLAGS_EXTENDED
+       def_bool y
+       depends on 64BIT || SPARSEMEM_VMEMMAP || !NUMA || !SPARSEMEM
+
 # Heavily threaded applications may benefit from splitting the mm-wide
 # page_table_lock, so that faults on different parts of the user address
 # space can be handled with less contention: split it at this NR_CPUS.