1config SELECT_MEMORY_MODEL 2 def_bool y 3 depends on EXPERIMENTAL || ARCH_SELECT_MEMORY_MODEL 4 5choice 6 prompt "Memory model" 7 depends on SELECT_MEMORY_MODEL 8 default DISCONTIGMEM_MANUAL if ARCH_DISCONTIGMEM_DEFAULT 9 default SPARSEMEM_MANUAL if ARCH_SPARSEMEM_DEFAULT 10 default FLATMEM_MANUAL 11 12config FLATMEM_MANUAL 13 bool "Flat Memory" 14 depends on !(ARCH_DISCONTIGMEM_ENABLE || ARCH_SPARSEMEM_ENABLE) || ARCH_FLATMEM_ENABLE 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 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. 30 31config DISCONTIGMEM_MANUAL 32 bool "Discontiguous Memory" 33 depends on ARCH_DISCONTIGMEM_ENABLE 34 help 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 the extra overhead that 41 this option imposes. 42 43 Many NUMA configurations will have this as the only option. 44 45 If unsure, choose "Flat Memory" over this option. 46 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 55 "Discontiguous Memory". This option provides some potential 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 62endchoice 63 64config DISCONTIGMEM 65 def_bool y 66 depends on (!SELECT_MEMORY_MODEL && ARCH_DISCONTIGMEM_ENABLE) || DISCONTIGMEM_MANUAL 67 68config SPARSEMEM 69 def_bool y 70 depends on SPARSEMEM_MANUAL 71 72config FLATMEM 73 def_bool y 74 depends on (!DISCONTIGMEM && !SPARSEMEM) || FLATMEM_MANUAL 75 76config FLAT_NODE_MEM_MAP 77 def_bool y 78 depends on !SPARSEMEM 79 80config HAVE_GET_USER_PAGES_FAST 81 bool 82 83# 84# Both the NUMA code and DISCONTIGMEM use arrays of pg_data_t's 85# to represent different areas of memory. This variable allows 86# those dependencies to exist individually. 87# 88config NEED_MULTIPLE_NODES 89 def_bool y 90 depends on DISCONTIGMEM || NUMA 91 92config HAVE_MEMORY_PRESENT 93 def_bool y 94 depends on ARCH_HAVE_MEMORY_PRESENT || SPARSEMEM 95 96# 97# SPARSEMEM_EXTREME (which is the default) does some bootmem 98# allocations when memory_present() is called. If this cannot 99# be done on your architecture, select this option. However, 100# statically allocating the mem_section[] array can potentially 101# consume vast quantities of .bss, so be careful. 102# 103# This option will also potentially produce smaller runtime code 104# with gcc 3.4 and later. 105# 106config SPARSEMEM_STATIC 107 def_bool n 108 109# 110# Architecture platforms which require a two level mem_section in SPARSEMEM 111# must select this option. This is usually for architecture platforms with 112# an extremely sparse physical address space. 113# 114config SPARSEMEM_EXTREME 115 def_bool y 116 depends on SPARSEMEM && !SPARSEMEM_STATIC 117 118config SPARSEMEM_VMEMMAP_ENABLE 119 def_bool n 120 121config SPARSEMEM_VMEMMAP 122 bool "Sparse Memory virtual memmap" 123 depends on SPARSEMEM && SPARSEMEM_VMEMMAP_ENABLE 124 default y 125 help 126 SPARSEMEM_VMEMMAP uses a virtually mapped memmap to optimise 127 pfn_to_page and page_to_pfn operations. This is the most 128 efficient option when sufficient kernel resources are available. 129 130# eventually, we can have this option just 'select SPARSEMEM' 131config MEMORY_HOTPLUG 132 bool "Allow for memory hot-add" 133 depends on SPARSEMEM || X86_64_ACPI_NUMA 134 depends on HOTPLUG && !HIBERNATION && ARCH_ENABLE_MEMORY_HOTPLUG 135 depends on (IA64 || X86 || PPC64 || SUPERH || S390) 136 137comment "Memory hotplug is currently incompatible with Software Suspend" 138 depends on SPARSEMEM && HOTPLUG && HIBERNATION 139 140config MEMORY_HOTPLUG_SPARSE 141 def_bool y 142 depends on SPARSEMEM && MEMORY_HOTPLUG 143 144config MEMORY_HOTREMOVE 145 bool "Allow for memory hot remove" 146 depends on MEMORY_HOTPLUG && ARCH_ENABLE_MEMORY_HOTREMOVE 147 depends on MIGRATION 148 149# 150# If we have space for more page flags then we can enable additional 151# optimizations and functionality. 152# 153# Regular Sparsemem takes page flag bits for the sectionid if it does not 154# use a virtual memmap. Disable extended page flags for 32 bit platforms 155# that require the use of a sectionid in the page flags. 156# 157config PAGEFLAGS_EXTENDED 158 def_bool y 159 depends on 64BIT || SPARSEMEM_VMEMMAP || !NUMA || !SPARSEMEM 160 161# Heavily threaded applications may benefit from splitting the mm-wide 162# page_table_lock, so that faults on different parts of the user address 163# space can be handled with less contention: split it at this NR_CPUS. 164# Default to 4 for wider testing, though 8 might be more appropriate. 165# ARM's adjust_pte (unused if VIPT) depends on mm-wide page_table_lock. 166# PA-RISC 7xxx's spinlock_t would enlarge struct page from 32 to 44 bytes. 167# 168config SPLIT_PTLOCK_CPUS 169 int 170 default "4096" if ARM && !CPU_CACHE_VIPT 171 default "4096" if PARISC && !PA20 172 default "4" 173 174# 175# support for page migration 176# 177config MIGRATION 178 bool "Page migration" 179 def_bool y 180 depends on NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE 181 help 182 Allows the migration of the physical location of pages of processes 183 while the virtual addresses are not changed. This is useful for 184 example on NUMA systems to put pages nearer to the processors accessing 185 the page. 186 187config RESOURCES_64BIT 188 bool "64 bit Memory and IO resources (EXPERIMENTAL)" if (!64BIT && EXPERIMENTAL) 189 default 64BIT 190 help 191 This option allows memory and IO resources to be 64 bit. 192 193config ZONE_DMA_FLAG 194 int 195 default "0" if !ZONE_DMA 196 default "1" 197 198config BOUNCE 199 def_bool y 200 depends on BLOCK && MMU && (ZONE_DMA || HIGHMEM) 201 202config NR_QUICK 203 int 204 depends on QUICKLIST 205 default "2" if SUPERH || AVR32 206 default "1" 207 208config VIRT_TO_BUS 209 def_bool y 210 depends on !ARCH_NO_VIRT_TO_BUS 211 212config MMU_NOTIFIER 213 bool 214