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Dave Hansene1785e82005-06-23 00:07:49 -07001config SELECT_MEMORY_MODEL
2 def_bool y
3 depends on EXPERIMENTAL || ARCH_SELECT_MEMORY_MODEL
4
Dave Hansen3a9da762005-06-23 00:07:42 -07005choice
6 prompt "Memory model"
Dave Hansene1785e82005-06-23 00:07:49 -07007 depends on SELECT_MEMORY_MODEL
8 default DISCONTIGMEM_MANUAL if ARCH_DISCONTIGMEM_DEFAULT
Andy Whitcroftd41dee32005-06-23 00:07:54 -07009 default SPARSEMEM_MANUAL if ARCH_SPARSEMEM_DEFAULT
Dave Hansene1785e82005-06-23 00:07:49 -070010 default FLATMEM_MANUAL
Dave Hansen3a9da762005-06-23 00:07:42 -070011
Dave Hansene1785e82005-06-23 00:07:49 -070012config FLATMEM_MANUAL
Dave Hansen3a9da762005-06-23 00:07:42 -070013 bool "Flat Memory"
Anton Blanchardc898ec12006-01-06 00:12:07 -080014 depends on !(ARCH_DISCONTIGMEM_ENABLE || ARCH_SPARSEMEM_ENABLE) || ARCH_FLATMEM_ENABLE
Dave Hansen3a9da762005-06-23 00:07:42 -070015 help
16 This option allows you to change some of the ways that
17 Linux manages its memory internally. Most users will
18 only have one option here: FLATMEM. This is normal
19 and a correct option.
20
Andy Whitcroftd41dee32005-06-23 00:07:54 -070021 Some users of more advanced features like NUMA and
22 memory hotplug may have different options here.
23 DISCONTIGMEM is an more mature, better tested system,
24 but is incompatible with memory hotplug and may suffer
25 decreased performance over SPARSEMEM. If unsure between
26 "Sparse Memory" and "Discontiguous Memory", choose
27 "Discontiguous Memory".
28
29 If unsure, choose this option (Flat Memory) over any other.
Dave Hansen3a9da762005-06-23 00:07:42 -070030
Dave Hansene1785e82005-06-23 00:07:49 -070031config DISCONTIGMEM_MANUAL
Dave Hansenf3519f92005-09-16 19:27:54 -070032 bool "Discontiguous Memory"
Dave Hansen3a9da762005-06-23 00:07:42 -070033 depends on ARCH_DISCONTIGMEM_ENABLE
34 help
Dave Hansen785dcd42005-06-23 00:07:50 -070035 This option provides enhanced support for discontiguous
36 memory systems, over FLATMEM. These systems have holes
37 in their physical address spaces, and this option provides
38 more efficient handling of these holes. However, the vast
39 majority of hardware has quite flat address spaces, and
40 can have degraded performance from extra overhead that
41 this option imposes.
42
43 Many NUMA configurations will have this as the only option.
44
Dave Hansen3a9da762005-06-23 00:07:42 -070045 If unsure, choose "Flat Memory" over this option.
46
Andy Whitcroftd41dee32005-06-23 00:07:54 -070047config SPARSEMEM_MANUAL
48 bool "Sparse Memory"
49 depends on ARCH_SPARSEMEM_ENABLE
50 help
51 This will be the only option for some systems, including
52 memory hotplug systems. This is normal.
53
54 For many other systems, this will be an alternative to
Dave Hansenf3519f92005-09-16 19:27:54 -070055 "Discontiguous Memory". This option provides some potential
Andy Whitcroftd41dee32005-06-23 00:07:54 -070056 performance benefits, along with decreased code complexity,
57 but it is newer, and more experimental.
58
59 If unsure, choose "Discontiguous Memory" or "Flat Memory"
60 over this option.
61
Dave Hansen3a9da762005-06-23 00:07:42 -070062endchoice
63
Dave Hansene1785e82005-06-23 00:07:49 -070064config DISCONTIGMEM
65 def_bool y
66 depends on (!SELECT_MEMORY_MODEL && ARCH_DISCONTIGMEM_ENABLE) || DISCONTIGMEM_MANUAL
67
Andy Whitcroftd41dee32005-06-23 00:07:54 -070068config SPARSEMEM
69 def_bool y
70 depends on SPARSEMEM_MANUAL
71
Dave Hansene1785e82005-06-23 00:07:49 -070072config FLATMEM
73 def_bool y
Andy Whitcroftd41dee32005-06-23 00:07:54 -070074 depends on (!DISCONTIGMEM && !SPARSEMEM) || FLATMEM_MANUAL
75
76config FLAT_NODE_MEM_MAP
77 def_bool y
78 depends on !SPARSEMEM
Dave Hansene1785e82005-06-23 00:07:49 -070079
Dave Hansen93b75042005-06-23 00:07:47 -070080#
81# Both the NUMA code and DISCONTIGMEM use arrays of pg_data_t's
82# to represent different areas of memory. This variable allows
83# those dependencies to exist individually.
84#
85config NEED_MULTIPLE_NODES
86 def_bool y
87 depends on DISCONTIGMEM || NUMA
Andy Whitcroftaf705362005-06-23 00:07:53 -070088
89config HAVE_MEMORY_PRESENT
90 def_bool y
Andy Whitcroftd41dee32005-06-23 00:07:54 -070091 depends on ARCH_HAVE_MEMORY_PRESENT || SPARSEMEM
Bob Picco802f1922005-09-03 15:54:26 -070092
93#
Bob Picco3e347262005-09-03 15:54:28 -070094# SPARSEMEM_EXTREME (which is the default) does some bootmem
Matt LaPlante84eb8d02006-10-03 22:53:09 +020095# allocations when memory_present() is called. If this cannot
Bob Picco3e347262005-09-03 15:54:28 -070096# be done on your architecture, select this option. However,
97# statically allocating the mem_section[] array can potentially
98# consume vast quantities of .bss, so be careful.
99#
100# This option will also potentially produce smaller runtime code
101# with gcc 3.4 and later.
102#
103config SPARSEMEM_STATIC
104 def_bool n
105
106#
Matt LaPlante44c09202006-10-03 22:34:14 +0200107# Architecture platforms which require a two level mem_section in SPARSEMEM
Bob Picco802f1922005-09-03 15:54:26 -0700108# must select this option. This is usually for architecture platforms with
109# an extremely sparse physical address space.
110#
Bob Picco3e347262005-09-03 15:54:28 -0700111config SPARSEMEM_EXTREME
112 def_bool y
113 depends on SPARSEMEM && !SPARSEMEM_STATIC
Hugh Dickins4c21e2f2005-10-29 18:16:40 -0700114
Dave Hansen3947be12005-10-29 18:16:54 -0700115# eventually, we can have this option just 'select SPARSEMEM'
116config MEMORY_HOTPLUG
117 bool "Allow for memory hot-add"
Keith Manntheyec69acb2006-09-30 23:27:05 -0700118 depends on SPARSEMEM || X86_64_ACPI_NUMA
119 depends on HOTPLUG && !SOFTWARE_SUSPEND && ARCH_ENABLE_MEMORY_HOTPLUG
Paul Mundt33d63bd2007-06-07 11:32:52 +0900120 depends on (IA64 || X86 || PPC64 || SUPERH)
Dave Hansen3947be12005-10-29 18:16:54 -0700121
122comment "Memory hotplug is currently incompatible with Software Suspend"
123 depends on SPARSEMEM && HOTPLUG && SOFTWARE_SUSPEND
124
Keith Manntheyec69acb2006-09-30 23:27:05 -0700125config MEMORY_HOTPLUG_SPARSE
126 def_bool y
127 depends on SPARSEMEM && MEMORY_HOTPLUG
128
Hugh Dickins4c21e2f2005-10-29 18:16:40 -0700129# Heavily threaded applications may benefit from splitting the mm-wide
130# page_table_lock, so that faults on different parts of the user address
131# space can be handled with less contention: split it at this NR_CPUS.
132# Default to 4 for wider testing, though 8 might be more appropriate.
133# ARM's adjust_pte (unused if VIPT) depends on mm-wide page_table_lock.
Hugh Dickins7b6ac9d2005-11-23 13:37:37 -0800134# PA-RISC 7xxx's spinlock_t would enlarge struct page from 32 to 44 bytes.
Hugh Dickins4c21e2f2005-10-29 18:16:40 -0700135#
136config SPLIT_PTLOCK_CPUS
137 int
138 default "4096" if ARM && !CPU_CACHE_VIPT
Hugh Dickins7b6ac9d2005-11-23 13:37:37 -0800139 default "4096" if PARISC && !PA20
Hugh Dickins4c21e2f2005-10-29 18:16:40 -0700140 default "4"
Christoph Lameter7cbe34c2006-01-08 01:00:49 -0800141
142#
143# support for page migration
144#
145config MIGRATION
Christoph Lameterb20a3502006-03-22 00:09:12 -0800146 bool "Page migration"
Christoph Lameter6c5240a2006-06-23 02:03:37 -0700147 def_bool y
148 depends on NUMA
Christoph Lameterb20a3502006-03-22 00:09:12 -0800149 help
150 Allows the migration of the physical location of pages of processes
151 while the virtual addresses are not changed. This is useful for
152 example on NUMA systems to put pages nearer to the processors accessing
153 the page.
Greg Kroah-Hartman6550e072006-06-12 17:11:31 -0700154
155config RESOURCES_64BIT
156 bool "64 bit Memory and IO resources (EXPERIMENTAL)" if (!64BIT && EXPERIMENTAL)
157 default 64BIT
158 help
159 This option allows memory and IO resources to be 64 bit.
Christoph Lameter4b51d662007-02-10 01:43:10 -0800160
161config ZONE_DMA_FLAG
162 int
163 default "0" if !ZONE_DMA
164 default "1"
165
Christoph Lameter6225e932007-05-06 14:49:50 -0700166config NR_QUICK
167 int
168 depends on QUICKLIST
Paul Mundt6c645ac2007-05-14 09:55:35 +0900169 default "2" if (SUPERH && !SUPERH64)
Christoph Lameter6225e932007-05-06 14:49:50 -0700170 default "1"