1e1785e85SDave Hansenconfig SELECT_MEMORY_MODEL 2e1785e85SDave Hansen def_bool y 3e1785e85SDave Hansen depends on EXPERIMENTAL || ARCH_SELECT_MEMORY_MODEL 4e1785e85SDave Hansen 53a9da765SDave Hansenchoice 63a9da765SDave Hansen prompt "Memory model" 7e1785e85SDave Hansen depends on SELECT_MEMORY_MODEL 8e1785e85SDave Hansen default DISCONTIGMEM_MANUAL if ARCH_DISCONTIGMEM_DEFAULT 9d41dee36SAndy Whitcroft default SPARSEMEM_MANUAL if ARCH_SPARSEMEM_DEFAULT 10e1785e85SDave Hansen default FLATMEM_MANUAL 113a9da765SDave Hansen 12e1785e85SDave Hansenconfig FLATMEM_MANUAL 133a9da765SDave Hansen bool "Flat Memory" 14c898ec16SAnton Blanchard depends on !(ARCH_DISCONTIGMEM_ENABLE || ARCH_SPARSEMEM_ENABLE) || ARCH_FLATMEM_ENABLE 153a9da765SDave Hansen help 163a9da765SDave Hansen This option allows you to change some of the ways that 173a9da765SDave Hansen Linux manages its memory internally. Most users will 183a9da765SDave Hansen only have one option here: FLATMEM. This is normal 193a9da765SDave Hansen and a correct option. 203a9da765SDave Hansen 21d41dee36SAndy Whitcroft Some users of more advanced features like NUMA and 22d41dee36SAndy Whitcroft memory hotplug may have different options here. 23d41dee36SAndy Whitcroft DISCONTIGMEM is an more mature, better tested system, 24d41dee36SAndy Whitcroft but is incompatible with memory hotplug and may suffer 25d41dee36SAndy Whitcroft decreased performance over SPARSEMEM. If unsure between 26d41dee36SAndy Whitcroft "Sparse Memory" and "Discontiguous Memory", choose 27d41dee36SAndy Whitcroft "Discontiguous Memory". 28d41dee36SAndy Whitcroft 29d41dee36SAndy Whitcroft If unsure, choose this option (Flat Memory) over any other. 303a9da765SDave Hansen 31e1785e85SDave Hansenconfig DISCONTIGMEM_MANUAL 32f3519f91SDave Hansen bool "Discontiguous Memory" 333a9da765SDave Hansen depends on ARCH_DISCONTIGMEM_ENABLE 343a9da765SDave Hansen help 35785dcd44SDave Hansen This option provides enhanced support for discontiguous 36785dcd44SDave Hansen memory systems, over FLATMEM. These systems have holes 37785dcd44SDave Hansen in their physical address spaces, and this option provides 38785dcd44SDave Hansen more efficient handling of these holes. However, the vast 39785dcd44SDave Hansen majority of hardware has quite flat address spaces, and 40785dcd44SDave Hansen can have degraded performance from extra overhead that 41785dcd44SDave Hansen this option imposes. 42785dcd44SDave Hansen 43785dcd44SDave Hansen Many NUMA configurations will have this as the only option. 44785dcd44SDave Hansen 453a9da765SDave Hansen If unsure, choose "Flat Memory" over this option. 463a9da765SDave Hansen 47d41dee36SAndy Whitcroftconfig SPARSEMEM_MANUAL 48d41dee36SAndy Whitcroft bool "Sparse Memory" 49d41dee36SAndy Whitcroft depends on ARCH_SPARSEMEM_ENABLE 50d41dee36SAndy Whitcroft help 51d41dee36SAndy Whitcroft This will be the only option for some systems, including 52d41dee36SAndy Whitcroft memory hotplug systems. This is normal. 53d41dee36SAndy Whitcroft 54d41dee36SAndy Whitcroft For many other systems, this will be an alternative to 55f3519f91SDave Hansen "Discontiguous Memory". This option provides some potential 56d41dee36SAndy Whitcroft performance benefits, along with decreased code complexity, 57d41dee36SAndy Whitcroft but it is newer, and more experimental. 58d41dee36SAndy Whitcroft 59d41dee36SAndy Whitcroft If unsure, choose "Discontiguous Memory" or "Flat Memory" 60d41dee36SAndy Whitcroft over this option. 61d41dee36SAndy Whitcroft 623a9da765SDave Hansenendchoice 633a9da765SDave Hansen 64e1785e85SDave Hansenconfig DISCONTIGMEM 65e1785e85SDave Hansen def_bool y 66e1785e85SDave Hansen depends on (!SELECT_MEMORY_MODEL && ARCH_DISCONTIGMEM_ENABLE) || DISCONTIGMEM_MANUAL 67e1785e85SDave Hansen 68d41dee36SAndy Whitcroftconfig SPARSEMEM 69d41dee36SAndy Whitcroft def_bool y 70d41dee36SAndy Whitcroft depends on SPARSEMEM_MANUAL 71d41dee36SAndy Whitcroft 72e1785e85SDave Hansenconfig FLATMEM 73e1785e85SDave Hansen def_bool y 74d41dee36SAndy Whitcroft depends on (!DISCONTIGMEM && !SPARSEMEM) || FLATMEM_MANUAL 75d41dee36SAndy Whitcroft 76d41dee36SAndy Whitcroftconfig FLAT_NODE_MEM_MAP 77d41dee36SAndy Whitcroft def_bool y 78d41dee36SAndy Whitcroft depends on !SPARSEMEM 79e1785e85SDave Hansen 8093b7504eSDave Hansen# 8193b7504eSDave Hansen# Both the NUMA code and DISCONTIGMEM use arrays of pg_data_t's 8293b7504eSDave Hansen# to represent different areas of memory. This variable allows 8393b7504eSDave Hansen# those dependencies to exist individually. 8493b7504eSDave Hansen# 8593b7504eSDave Hansenconfig NEED_MULTIPLE_NODES 8693b7504eSDave Hansen def_bool y 8793b7504eSDave Hansen depends on DISCONTIGMEM || NUMA 88af705362SAndy Whitcroft 89af705362SAndy Whitcroftconfig HAVE_MEMORY_PRESENT 90af705362SAndy Whitcroft def_bool y 91d41dee36SAndy Whitcroft depends on ARCH_HAVE_MEMORY_PRESENT || SPARSEMEM 92802f192eSBob Picco 93802f192eSBob Picco# 943e347261SBob Picco# SPARSEMEM_EXTREME (which is the default) does some bootmem 953e347261SBob Picco# allocations when memory_present() is called. If this cannot 963e347261SBob Picco# be done on your architecture, select this option. However, 973e347261SBob Picco# statically allocating the mem_section[] array can potentially 983e347261SBob Picco# consume vast quantities of .bss, so be careful. 993e347261SBob Picco# 1003e347261SBob Picco# This option will also potentially produce smaller runtime code 1013e347261SBob Picco# with gcc 3.4 and later. 1023e347261SBob Picco# 1033e347261SBob Piccoconfig SPARSEMEM_STATIC 1043e347261SBob Picco def_bool n 1053e347261SBob Picco 1063e347261SBob Picco# 10744c09201SMatt LaPlante# Architecture platforms which require a two level mem_section in SPARSEMEM 108802f192eSBob Picco# must select this option. This is usually for architecture platforms with 109802f192eSBob Picco# an extremely sparse physical address space. 110802f192eSBob Picco# 1113e347261SBob Piccoconfig SPARSEMEM_EXTREME 1123e347261SBob Picco def_bool y 1133e347261SBob Picco depends on SPARSEMEM && !SPARSEMEM_STATIC 1144c21e2f2SHugh Dickins 1153947be19SDave Hansen# eventually, we can have this option just 'select SPARSEMEM' 1163947be19SDave Hansenconfig MEMORY_HOTPLUG 1173947be19SDave Hansen bool "Allow for memory hot-add" 118ec69acbbSKeith Mannthey depends on SPARSEMEM || X86_64_ACPI_NUMA 119b0cb1a19SRafael J. Wysocki depends on HOTPLUG && !HIBERNATION && ARCH_ENABLE_MEMORY_HOTPLUG 12033d63bd8SPaul Mundt depends on (IA64 || X86 || PPC64 || SUPERH) 1213947be19SDave Hansen 1223947be19SDave Hansencomment "Memory hotplug is currently incompatible with Software Suspend" 123b0cb1a19SRafael J. Wysocki depends on SPARSEMEM && HOTPLUG && HIBERNATION 1243947be19SDave Hansen 125ec69acbbSKeith Manntheyconfig MEMORY_HOTPLUG_SPARSE 126ec69acbbSKeith Mannthey def_bool y 127ec69acbbSKeith Mannthey depends on SPARSEMEM && MEMORY_HOTPLUG 128ec69acbbSKeith Mannthey 1294c21e2f2SHugh Dickins# Heavily threaded applications may benefit from splitting the mm-wide 1304c21e2f2SHugh Dickins# page_table_lock, so that faults on different parts of the user address 1314c21e2f2SHugh Dickins# space can be handled with less contention: split it at this NR_CPUS. 1324c21e2f2SHugh Dickins# Default to 4 for wider testing, though 8 might be more appropriate. 1334c21e2f2SHugh Dickins# ARM's adjust_pte (unused if VIPT) depends on mm-wide page_table_lock. 1347b6ac9dfSHugh Dickins# PA-RISC 7xxx's spinlock_t would enlarge struct page from 32 to 44 bytes. 1354c21e2f2SHugh Dickins# 1364c21e2f2SHugh Dickinsconfig SPLIT_PTLOCK_CPUS 1374c21e2f2SHugh Dickins int 1384c21e2f2SHugh Dickins default "4096" if ARM && !CPU_CACHE_VIPT 1397b6ac9dfSHugh Dickins default "4096" if PARISC && !PA20 1404c21e2f2SHugh Dickins default "4" 1417cbe34cfSChristoph Lameter 1427cbe34cfSChristoph Lameter# 1437cbe34cfSChristoph Lameter# support for page migration 1447cbe34cfSChristoph Lameter# 1457cbe34cfSChristoph Lameterconfig MIGRATION 146b20a3503SChristoph Lameter bool "Page migration" 1476c5240aeSChristoph Lameter def_bool y 1486c5240aeSChristoph Lameter depends on NUMA 149b20a3503SChristoph Lameter help 150b20a3503SChristoph Lameter Allows the migration of the physical location of pages of processes 151b20a3503SChristoph Lameter while the virtual addresses are not changed. This is useful for 152b20a3503SChristoph Lameter example on NUMA systems to put pages nearer to the processors accessing 153b20a3503SChristoph Lameter the page. 1546550e07fSGreg Kroah-Hartman 1556550e07fSGreg Kroah-Hartmanconfig RESOURCES_64BIT 1566550e07fSGreg Kroah-Hartman bool "64 bit Memory and IO resources (EXPERIMENTAL)" if (!64BIT && EXPERIMENTAL) 1576550e07fSGreg Kroah-Hartman default 64BIT 1586550e07fSGreg Kroah-Hartman help 1596550e07fSGreg Kroah-Hartman This option allows memory and IO resources to be 64 bit. 1604b51d669SChristoph Lameter 1614b51d669SChristoph Lameterconfig ZONE_DMA_FLAG 1624b51d669SChristoph Lameter int 1634b51d669SChristoph Lameter default "0" if !ZONE_DMA 1644b51d669SChristoph Lameter default "1" 1654b51d669SChristoph Lameter 1662a7326b5SChristoph Lameterconfig BOUNCE 1672a7326b5SChristoph Lameter def_bool y 1682a7326b5SChristoph Lameter depends on BLOCK && MMU && (ZONE_DMA || HIGHMEM) 1692a7326b5SChristoph Lameter 1706225e937SChristoph Lameterconfig NR_QUICK 1716225e937SChristoph Lameter int 1726225e937SChristoph Lameter depends on QUICKLIST 1736c645ac7SPaul Mundt default "2" if (SUPERH && !SUPERH64) 1746225e937SChristoph Lameter default "1" 175f057eac0SStephen Rothwell 176f057eac0SStephen Rothwellconfig VIRT_TO_BUS 177f057eac0SStephen Rothwell def_bool y 178f057eac0SStephen Rothwell depends on !ARCH_NO_VIRT_TO_BUS 179