]> bbs.cooldavid.org Git - net-next-2.6.git/blame - mm/Kconfig
mpu401 warning fixes
[net-next-2.6.git] / mm / Kconfig
CommitLineData
e1785e85
DH
1config SELECT_MEMORY_MODEL
2 def_bool y
3 depends on EXPERIMENTAL || ARCH_SELECT_MEMORY_MODEL
4
3a9da765
DH
5choice
6 prompt "Memory model"
e1785e85
DH
7 depends on SELECT_MEMORY_MODEL
8 default DISCONTIGMEM_MANUAL if ARCH_DISCONTIGMEM_DEFAULT
d41dee36 9 default SPARSEMEM_MANUAL if ARCH_SPARSEMEM_DEFAULT
e1785e85 10 default FLATMEM_MANUAL
3a9da765 11
e1785e85 12config FLATMEM_MANUAL
3a9da765 13 bool "Flat Memory"
c898ec16 14 depends on !(ARCH_DISCONTIGMEM_ENABLE || ARCH_SPARSEMEM_ENABLE) || ARCH_FLATMEM_ENABLE
3a9da765
DH
15 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
d41dee36
AW
21 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.
3a9da765 30
e1785e85 31config DISCONTIGMEM_MANUAL
f3519f91 32 bool "Discontiguous Memory"
3a9da765
DH
33 depends on ARCH_DISCONTIGMEM_ENABLE
34 help
785dcd44
DH
35 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
3a9da765
DH
45 If unsure, choose "Flat Memory" over this option.
46
d41dee36
AW
47config 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
f3519f91 55 "Discontiguous Memory". This option provides some potential
d41dee36
AW
56 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
3a9da765
DH
62endchoice
63
e1785e85
DH
64config DISCONTIGMEM
65 def_bool y
66 depends on (!SELECT_MEMORY_MODEL && ARCH_DISCONTIGMEM_ENABLE) || DISCONTIGMEM_MANUAL
67
d41dee36
AW
68config SPARSEMEM
69 def_bool y
70 depends on SPARSEMEM_MANUAL
71
e1785e85
DH
72config FLATMEM
73 def_bool y
d41dee36
AW
74 depends on (!DISCONTIGMEM && !SPARSEMEM) || FLATMEM_MANUAL
75
76config FLAT_NODE_MEM_MAP
77 def_bool y
78 depends on !SPARSEMEM
e1785e85 79
93b7504e
DH
80#
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
af705362
AW
88
89config HAVE_MEMORY_PRESENT
90 def_bool y
d41dee36 91 depends on ARCH_HAVE_MEMORY_PRESENT || SPARSEMEM
802f192e 92
3e347261
BP
93#
94# SPARSEMEM_EXTREME (which is the default) does some bootmem
84eb8d06 95# allocations when memory_present() is called. If this cannot
3e347261
BP
96# 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
802f192e 106#
44c09201 107# Architecture platforms which require a two level mem_section in SPARSEMEM
802f192e
BP
108# must select this option. This is usually for architecture platforms with
109# an extremely sparse physical address space.
110#
3e347261
BP
111config SPARSEMEM_EXTREME
112 def_bool y
113 depends on SPARSEMEM && !SPARSEMEM_STATIC
4c21e2f2 114
3947be19
DH
115# eventually, we can have this option just 'select SPARSEMEM'
116config MEMORY_HOTPLUG
117 bool "Allow for memory hot-add"
ec69acbb
KM
118 depends on SPARSEMEM || X86_64_ACPI_NUMA
119 depends on HOTPLUG && !SOFTWARE_SUSPEND && ARCH_ENABLE_MEMORY_HOTPLUG
1f04bbd2 120 depends on (IA64 || X86 || PPC64)
3947be19
DH
121
122comment "Memory hotplug is currently incompatible with Software Suspend"
123 depends on SPARSEMEM && HOTPLUG && SOFTWARE_SUSPEND
124
ec69acbb
KM
125config MEMORY_HOTPLUG_SPARSE
126 def_bool y
127 depends on SPARSEMEM && MEMORY_HOTPLUG
128
4c21e2f2
HD
129# 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.
7b6ac9df 134# PA-RISC 7xxx's spinlock_t would enlarge struct page from 32 to 44 bytes.
4c21e2f2
HD
135#
136config SPLIT_PTLOCK_CPUS
137 int
138 default "4096" if ARM && !CPU_CACHE_VIPT
7b6ac9df 139 default "4096" if PARISC && !PA20
4c21e2f2 140 default "4"
7cbe34cf
CL
141
142#
143# support for page migration
144#
145config MIGRATION
b20a3503 146 bool "Page migration"
6c5240ae
CL
147 def_bool y
148 depends on NUMA
b20a3503
CL
149 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.
6550e07f
GKH
154
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.
4b51d669
CL
160
161config ZONE_DMA_FLAG
162 int
163 default "0" if !ZONE_DMA
164 default "1"
165
6225e937
CL
166config NR_QUICK
167 int
168 depends on QUICKLIST
6c645ac7 169 default "2" if (SUPERH && !SUPERH64)
6225e937 170 default "1"