config SELECT_MEMORY_MODEL	def_bool y	depends on EXPERIMENTAL || ARCH_SELECT_MEMORY_MODEL choice	prompt "Memory model"	depends on SELECT_MEMORY_MODEL	default DISCONTIGMEM_MANUAL if ARCH_DISCONTIGMEM_DEFAULT	default SPARSEMEM_MANUAL if ARCH_SPARSEMEM_DEFAULT	default FLATMEM_MANUAL config FLATMEM_MANUAL	bool "Flat Memory"	depends on !(ARCH_DISCONTIGMEM_ENABLE || ARCH_SPARSEMEM_ENABLE) || ARCH_FLATMEM_ENABLE	help	  This option allows you to change some of the ways that	  Linux manages its memory internally.  Most users will	  only have one option here: FLATMEM.  This is normal	  and a correct option. 	  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". 	  If unsure, choose this option (Flat Memory) over any other. config DISCONTIGMEM_MANUAL	bool "Discontiguous 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	  "Discontiguous 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 # eventually, we can have this option just 'select SPARSEMEM'config MEMORY_HOTPLUG	bool "Allow for memory hot-add"	depends on SPARSEMEM && HOTPLUG && !SOFTWARE_SUSPEND comment "Memory hotplug is currently incompatible with Software Suspend"	depends on SPARSEMEM && HOTPLUG && SOFTWARE_SUSPEND # 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.# Default to 4 for wider testing, though 8 might be more appropriate.# ARM's adjust_pte (unused if VIPT) depends on mm-wide page_table_lock.# PA-RISC 7xxx's spinlock_t would enlarge struct page from 32 to 44 bytes.#config SPLIT_PTLOCK_CPUS	int	default "4096" if ARM && !CPU_CACHE_VIPT	default "4096" if PARISC && !PA20	default "4" ## support for page migration#config MIGRATION	bool "Page migration"	def_bool y if NUMA	depends on SWAP && NUMA	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.