mm: add comment why mark_page_accessed() would be better than pte_mkyoung() in follow...

[safe/jmp/linux-2.6] / mm / Kconfig

diff --git a/mm/Kconfig b/mm/Kconfig
index bd80460..a5b7781 100644 (file)
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -37,7 +37,7 @@ config DISCONTIGMEM_MANUAL
          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
+         can have degraded performance from the extra overhead that
          this option imposes.
 
          Many NUMA configurations will have this as the only option.
@@ -92,7 +92,7 @@ config HAVE_MEMORY_PRESENT
 
 #
 # SPARSEMEM_EXTREME (which is the default) does some bootmem
-# allocations when memory_present() is called.  If this can not
+# allocations when memory_present() is called.  If this cannot
 # 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.
@@ -101,10 +101,10 @@ config HAVE_MEMORY_PRESENT
 # with gcc 3.4 and later.
 #
 config SPARSEMEM_STATIC
-       def_bool n
+       bool
 
 #
-# Architectecture platforms which require a two level mem_section in SPARSEMEM
+# Architecture 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.
 #
@@ -112,13 +112,48 @@ config SPARSEMEM_EXTREME
        def_bool y
        depends on SPARSEMEM && !SPARSEMEM_STATIC
 
+config SPARSEMEM_VMEMMAP_ENABLE
+       bool
+
+config SPARSEMEM_VMEMMAP
+       bool "Sparse Memory virtual memmap"
+       depends on SPARSEMEM && SPARSEMEM_VMEMMAP_ENABLE
+       default y
+       help
+        SPARSEMEM_VMEMMAP uses a virtually mapped memmap to optimise
+        pfn_to_page and page_to_pfn operations.  This is the most
+        efficient option when sufficient kernel resources are available.
+
 # eventually, we can have this option just 'select SPARSEMEM'
 config MEMORY_HOTPLUG
        bool "Allow for memory hot-add"
-       depends on SPARSEMEM && HOTPLUG && !SOFTWARE_SUSPEND
+       depends on SPARSEMEM || X86_64_ACPI_NUMA
+       depends on HOTPLUG && !HIBERNATION && ARCH_ENABLE_MEMORY_HOTPLUG
+       depends on (IA64 || X86 || PPC64 || SUPERH || S390)
 
 comment "Memory hotplug is currently incompatible with Software Suspend"
-       depends on SPARSEMEM && HOTPLUG && SOFTWARE_SUSPEND
+       depends on SPARSEMEM && HOTPLUG && HIBERNATION
+
+config MEMORY_HOTPLUG_SPARSE
+       def_bool y
+       depends on SPARSEMEM && MEMORY_HOTPLUG
+
+config MEMORY_HOTREMOVE
+       bool "Allow for memory hot remove"
+       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
@@ -138,10 +173,46 @@ config SPLIT_PTLOCK_CPUS
 #
 config MIGRATION
        bool "Page migration"
-       def_bool y if NUMA || SPARSEMEM || DISCONTIGMEM
-       depends on SWAP
+       def_bool y
+       depends on NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE
        help
          Allows the migration of the physical location of pages of processes
          while the virtual addresses are not changed. This is useful for
          example on NUMA systems to put pages nearer to the processors accessing
          the page.
+
+config PHYS_ADDR_T_64BIT
+       def_bool 64BIT || ARCH_PHYS_ADDR_T_64BIT
+
+config ZONE_DMA_FLAG
+       int
+       default "0" if !ZONE_DMA
+       default "1"
+
+config BOUNCE
+       def_bool y
+       depends on BLOCK && MMU && (ZONE_DMA || HIGHMEM)
+
+config NR_QUICK
+       int
+       depends on QUICKLIST
+       default "2" if SUPERH || AVR32
+       default "1"
+
+config VIRT_TO_BUS
+       def_bool y
+       depends on !ARCH_NO_VIRT_TO_BUS
+
+config UNEVICTABLE_LRU
+       bool "Add LRU list to track non-evictable pages"
+       default y
+       depends on MMU
+       help
+         Keeps unevictable pages off of the active and inactive pageout
+         lists, so kswapd will not waste CPU time or have its balancing
+         algorithms thrown off by scanning these pages.  Selecting this
+         will use one page flag and increase the code size a little,
+         say Y unless you know what you are doing.
+
+config MMU_NOTIFIER
+       bool