| Dave Hansen | e1785e8 | 2005-06-23 00:07:49 -0700 | [diff] [blame] | 1 | config SELECT_MEMORY_MODEL |
| 2 | def_bool y |
| 3 | depends on EXPERIMENTAL || ARCH_SELECT_MEMORY_MODEL |
| 4 | |
| Dave Hansen | 3a9da76 | 2005-06-23 00:07:42 -0700 | [diff] [blame] | 5 | choice |
| 6 | prompt "Memory model" |
| Dave Hansen | e1785e8 | 2005-06-23 00:07:49 -0700 | [diff] [blame] | 7 | depends on SELECT_MEMORY_MODEL |
| 8 | default DISCONTIGMEM_MANUAL if ARCH_DISCONTIGMEM_DEFAULT |
| Andy Whitcroft | d41dee3 | 2005-06-23 00:07:54 -0700 | [diff] [blame] | 9 | default SPARSEMEM_MANUAL if ARCH_SPARSEMEM_DEFAULT |
| Dave Hansen | e1785e8 | 2005-06-23 00:07:49 -0700 | [diff] [blame] | 10 | default FLATMEM_MANUAL |
| Dave Hansen | 3a9da76 | 2005-06-23 00:07:42 -0700 | [diff] [blame] | 11 | |
| Dave Hansen | e1785e8 | 2005-06-23 00:07:49 -0700 | [diff] [blame] | 12 | config FLATMEM_MANUAL |
| Dave Hansen | 3a9da76 | 2005-06-23 00:07:42 -0700 | [diff] [blame] | 13 | bool "Flat Memory" |
| 14 | depends on !ARCH_DISCONTIGMEM_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 | |
| Andy Whitcroft | d41dee3 | 2005-06-23 00:07:54 -0700 | [diff] [blame] | 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. |
| Dave Hansen | 3a9da76 | 2005-06-23 00:07:42 -0700 | [diff] [blame] | 30 | |
| Dave Hansen | e1785e8 | 2005-06-23 00:07:49 -0700 | [diff] [blame] | 31 | config DISCONTIGMEM_MANUAL |
| Dave Hansen | 3a9da76 | 2005-06-23 00:07:42 -0700 | [diff] [blame] | 32 | bool "Discontigious Memory" |
| 33 | depends on ARCH_DISCONTIGMEM_ENABLE |
| 34 | help |
| Dave Hansen | 785dcd4 | 2005-06-23 00:07:50 -0700 | [diff] [blame] | 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 | |
| Dave Hansen | 3a9da76 | 2005-06-23 00:07:42 -0700 | [diff] [blame] | 45 | If unsure, choose "Flat Memory" over this option. |
| 46 | |
| Andy Whitcroft | d41dee3 | 2005-06-23 00:07:54 -0700 | [diff] [blame] | 47 | config 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 | "Discontigious 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 | |
| Dave Hansen | 3a9da76 | 2005-06-23 00:07:42 -0700 | [diff] [blame] | 62 | endchoice |
| 63 | |
| Dave Hansen | e1785e8 | 2005-06-23 00:07:49 -0700 | [diff] [blame] | 64 | config DISCONTIGMEM |
| 65 | def_bool y |
| 66 | depends on (!SELECT_MEMORY_MODEL && ARCH_DISCONTIGMEM_ENABLE) || DISCONTIGMEM_MANUAL |
| 67 | |
| Andy Whitcroft | d41dee3 | 2005-06-23 00:07:54 -0700 | [diff] [blame] | 68 | config SPARSEMEM |
| 69 | def_bool y |
| 70 | depends on SPARSEMEM_MANUAL |
| 71 | |
| Dave Hansen | e1785e8 | 2005-06-23 00:07:49 -0700 | [diff] [blame] | 72 | config FLATMEM |
| 73 | def_bool y |
| Andy Whitcroft | d41dee3 | 2005-06-23 00:07:54 -0700 | [diff] [blame] | 74 | depends on (!DISCONTIGMEM && !SPARSEMEM) || FLATMEM_MANUAL |
| 75 | |
| 76 | config FLAT_NODE_MEM_MAP |
| 77 | def_bool y |
| 78 | depends on !SPARSEMEM |
| Dave Hansen | e1785e8 | 2005-06-23 00:07:49 -0700 | [diff] [blame] | 79 | |
| Dave Hansen | 93b7504 | 2005-06-23 00:07:47 -0700 | [diff] [blame] | 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 | # |
| 85 | config NEED_MULTIPLE_NODES |
| 86 | def_bool y |
| 87 | depends on DISCONTIGMEM || NUMA |
| Andy Whitcroft | af70536 | 2005-06-23 00:07:53 -0700 | [diff] [blame] | 88 | |
| 89 | config HAVE_MEMORY_PRESENT |
| 90 | def_bool y |
| Andy Whitcroft | d41dee3 | 2005-06-23 00:07:54 -0700 | [diff] [blame] | 91 | depends on ARCH_HAVE_MEMORY_PRESENT || SPARSEMEM |