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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
Andy Whitcroft29c71112007-10-16 01:24:14 -0700115#
116# SPARSEMEM_VMEMMAP uses a virtually mapped mem_map to optimise pfn_to_page
117# and page_to_pfn. The most efficient option where kernel virtual space is
118# not under pressure.
119#
120config SPARSEMEM_VMEMMAP_ENABLE
121 def_bool n
122
123config SPARSEMEM_VMEMMAP
124 bool
125 depends on SPARSEMEM
126 default y if (SPARSEMEM_VMEMMAP_ENABLE)
127
Dave Hansen3947be12005-10-29 18:16:54 -0700128# eventually, we can have this option just 'select SPARSEMEM'
129config MEMORY_HOTPLUG
130 bool "Allow for memory hot-add"
Keith Manntheyec69acb2006-09-30 23:27:05 -0700131 depends on SPARSEMEM || X86_64_ACPI_NUMA
Rafael J. Wysockib0cb1a12007-07-29 23:24:36 +0200132 depends on HOTPLUG && !HIBERNATION && ARCH_ENABLE_MEMORY_HOTPLUG
Paul Mundt33d63bd2007-06-07 11:32:52 +0900133 depends on (IA64 || X86 || PPC64 || SUPERH)
Dave Hansen3947be12005-10-29 18:16:54 -0700134
135comment "Memory hotplug is currently incompatible with Software Suspend"
Rafael J. Wysockib0cb1a12007-07-29 23:24:36 +0200136 depends on SPARSEMEM && HOTPLUG && HIBERNATION
Dave Hansen3947be12005-10-29 18:16:54 -0700137
Keith Manntheyec69acb2006-09-30 23:27:05 -0700138config MEMORY_HOTPLUG_SPARSE
139 def_bool y
140 depends on SPARSEMEM && MEMORY_HOTPLUG
141
Hugh Dickins4c21e2f2005-10-29 18:16:40 -0700142# Heavily threaded applications may benefit from splitting the mm-wide
143# page_table_lock, so that faults on different parts of the user address
144# space can be handled with less contention: split it at this NR_CPUS.
145# Default to 4 for wider testing, though 8 might be more appropriate.
146# ARM's adjust_pte (unused if VIPT) depends on mm-wide page_table_lock.
Hugh Dickins7b6ac9d2005-11-23 13:37:37 -0800147# PA-RISC 7xxx's spinlock_t would enlarge struct page from 32 to 44 bytes.
Hugh Dickins4c21e2f2005-10-29 18:16:40 -0700148#
149config SPLIT_PTLOCK_CPUS
150 int
151 default "4096" if ARM && !CPU_CACHE_VIPT
Hugh Dickins7b6ac9d2005-11-23 13:37:37 -0800152 default "4096" if PARISC && !PA20
Jeremy Fitzhardinge67dd5a22007-10-05 17:19:35 -0700153 default "4096" if XEN
Hugh Dickins4c21e2f2005-10-29 18:16:40 -0700154 default "4"
Christoph Lameter7cbe34c2006-01-08 01:00:49 -0800155
156#
157# support for page migration
158#
159config MIGRATION
Christoph Lameterb20a3502006-03-22 00:09:12 -0800160 bool "Page migration"
Christoph Lameter6c5240a2006-06-23 02:03:37 -0700161 def_bool y
162 depends on NUMA
Christoph Lameterb20a3502006-03-22 00:09:12 -0800163 help
164 Allows the migration of the physical location of pages of processes
165 while the virtual addresses are not changed. This is useful for
166 example on NUMA systems to put pages nearer to the processors accessing
167 the page.
Greg Kroah-Hartman6550e072006-06-12 17:11:31 -0700168
169config RESOURCES_64BIT
170 bool "64 bit Memory and IO resources (EXPERIMENTAL)" if (!64BIT && EXPERIMENTAL)
171 default 64BIT
172 help
173 This option allows memory and IO resources to be 64 bit.
Christoph Lameter4b51d662007-02-10 01:43:10 -0800174
175config ZONE_DMA_FLAG
176 int
177 default "0" if !ZONE_DMA
178 default "1"
179
Christoph Lameter2a7326b2007-07-17 04:03:37 -0700180config BOUNCE
181 def_bool y
182 depends on BLOCK && MMU && (ZONE_DMA || HIGHMEM)
183
Christoph Lameter6225e932007-05-06 14:49:50 -0700184config NR_QUICK
185 int
186 depends on QUICKLIST
Paul Mundt6c645ac2007-05-14 09:55:35 +0900187 default "2" if (SUPERH && !SUPERH64)
Christoph Lameter6225e932007-05-06 14:49:50 -0700188 default "1"
Stephen Rothwellf057eac2007-07-15 23:40:05 -0700189
190config VIRT_TO_BUS
191 def_bool y
192 depends on !ARCH_NO_VIRT_TO_BUS