Dave Hansen | e1785e8 | 2005-06-23 00:07:49 -0700 | [diff] [blame] | 1 | config SELECT_MEMORY_MODEL |
| 2 | def_bool y |
Kees Cook | a8826ee | 2013-01-16 18:54:17 -0800 | [diff] [blame] | 3 | depends on ARCH_SELECT_MEMORY_MODEL |
Dave Hansen | e1785e8 | 2005-06-23 00:07:49 -0700 | [diff] [blame] | 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" |
Anton Blanchard | c898ec1 | 2006-01-06 00:12:07 -0800 | [diff] [blame] | 14 | depends on !(ARCH_DISCONTIGMEM_ENABLE || ARCH_SPARSEMEM_ENABLE) || ARCH_FLATMEM_ENABLE |
Dave Hansen | 3a9da76 | 2005-06-23 00:07:42 -0700 | [diff] [blame] | 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. |
Geert Uytterhoeven | 18f6533 | 2013-09-15 12:01:33 +0200 | [diff] [blame] | 23 | DISCONTIGMEM is a more mature, better tested system, |
Andy Whitcroft | d41dee3 | 2005-06-23 00:07:54 -0700 | [diff] [blame] | 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 | f3519f9 | 2005-09-16 19:27:54 -0700 | [diff] [blame] | 32 | bool "Discontiguous Memory" |
Dave Hansen | 3a9da76 | 2005-06-23 00:07:42 -0700 | [diff] [blame] | 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 |
Philipp Marek | ad3d0a3 | 2007-10-20 02:46:58 +0200 | [diff] [blame] | 40 | can have degraded performance from the extra overhead that |
Dave Hansen | 785dcd4 | 2005-06-23 00:07:50 -0700 | [diff] [blame] | 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 |
Dave Hansen | f3519f9 | 2005-09-16 19:27:54 -0700 | [diff] [blame] | 55 | "Discontiguous Memory". This option provides some potential |
Andy Whitcroft | d41dee3 | 2005-06-23 00:07:54 -0700 | [diff] [blame] | 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 |
Russell King | 1a83e17 | 2009-10-26 16:50:12 -0700 | [diff] [blame] | 70 | depends on (!SELECT_MEMORY_MODEL && ARCH_SPARSEMEM_ENABLE) || SPARSEMEM_MANUAL |
Andy Whitcroft | d41dee3 | 2005-06-23 00:07:54 -0700 | [diff] [blame] | 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 |
Bob Picco | 802f192 | 2005-09-03 15:54:26 -0700 | [diff] [blame] | 92 | |
| 93 | # |
Bob Picco | 3e34726 | 2005-09-03 15:54:28 -0700 | [diff] [blame] | 94 | # SPARSEMEM_EXTREME (which is the default) does some bootmem |
Matt LaPlante | 84eb8d0 | 2006-10-03 22:53:09 +0200 | [diff] [blame] | 95 | # allocations when memory_present() is called. If this cannot |
Bob Picco | 3e34726 | 2005-09-03 15:54:28 -0700 | [diff] [blame] | 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 | # |
| 103 | config SPARSEMEM_STATIC |
Jan Beulich | 9ba1608 | 2008-10-15 22:01:38 -0700 | [diff] [blame] | 104 | bool |
Bob Picco | 3e34726 | 2005-09-03 15:54:28 -0700 | [diff] [blame] | 105 | |
| 106 | # |
Matt LaPlante | 44c0920 | 2006-10-03 22:34:14 +0200 | [diff] [blame] | 107 | # Architecture platforms which require a two level mem_section in SPARSEMEM |
Bob Picco | 802f192 | 2005-09-03 15:54:26 -0700 | [diff] [blame] | 108 | # must select this option. This is usually for architecture platforms with |
| 109 | # an extremely sparse physical address space. |
| 110 | # |
Bob Picco | 3e34726 | 2005-09-03 15:54:28 -0700 | [diff] [blame] | 111 | config SPARSEMEM_EXTREME |
| 112 | def_bool y |
| 113 | depends on SPARSEMEM && !SPARSEMEM_STATIC |
Hugh Dickins | 4c21e2f | 2005-10-29 18:16:40 -0700 | [diff] [blame] | 114 | |
Andy Whitcroft | 29c7111 | 2007-10-16 01:24:14 -0700 | [diff] [blame] | 115 | config SPARSEMEM_VMEMMAP_ENABLE |
Jan Beulich | 9ba1608 | 2008-10-15 22:01:38 -0700 | [diff] [blame] | 116 | bool |
Andy Whitcroft | 29c7111 | 2007-10-16 01:24:14 -0700 | [diff] [blame] | 117 | |
Yinghai Lu | 9bdac91 | 2010-02-10 01:20:22 -0800 | [diff] [blame] | 118 | config SPARSEMEM_ALLOC_MEM_MAP_TOGETHER |
| 119 | def_bool y |
| 120 | depends on SPARSEMEM && X86_64 |
| 121 | |
Andy Whitcroft | 29c7111 | 2007-10-16 01:24:14 -0700 | [diff] [blame] | 122 | config SPARSEMEM_VMEMMAP |
Geoff Levand | a5ee6da | 2007-12-17 16:19:53 -0800 | [diff] [blame] | 123 | bool "Sparse Memory virtual memmap" |
| 124 | depends on SPARSEMEM && SPARSEMEM_VMEMMAP_ENABLE |
| 125 | default y |
| 126 | help |
| 127 | SPARSEMEM_VMEMMAP uses a virtually mapped memmap to optimise |
| 128 | pfn_to_page and page_to_pfn operations. This is the most |
| 129 | efficient option when sufficient kernel resources are available. |
Andy Whitcroft | 29c7111 | 2007-10-16 01:24:14 -0700 | [diff] [blame] | 130 | |
Yinghai Lu | 95f72d1 | 2010-07-12 14:36:09 +1000 | [diff] [blame] | 131 | config HAVE_MEMBLOCK |
Christoph Jaeger | 6341e62 | 2014-12-20 15:41:11 -0500 | [diff] [blame] | 132 | bool |
Yinghai Lu | 95f72d1 | 2010-07-12 14:36:09 +1000 | [diff] [blame] | 133 | |
Tejun Heo | 7c0caeb | 2011-07-14 11:43:42 +0200 | [diff] [blame] | 134 | config HAVE_MEMBLOCK_NODE_MAP |
Christoph Jaeger | 6341e62 | 2014-12-20 15:41:11 -0500 | [diff] [blame] | 135 | bool |
Tejun Heo | 7c0caeb | 2011-07-14 11:43:42 +0200 | [diff] [blame] | 136 | |
Philipp Hachtmann | 70210ed | 2014-01-29 18:16:01 +0100 | [diff] [blame] | 137 | config HAVE_MEMBLOCK_PHYS_MAP |
Christoph Jaeger | 6341e62 | 2014-12-20 15:41:11 -0500 | [diff] [blame] | 138 | bool |
Philipp Hachtmann | 70210ed | 2014-01-29 18:16:01 +0100 | [diff] [blame] | 139 | |
Steve Capper | 2667f50 | 2014-10-09 15:29:14 -0700 | [diff] [blame] | 140 | config HAVE_GENERIC_RCU_GUP |
Christoph Jaeger | 6341e62 | 2014-12-20 15:41:11 -0500 | [diff] [blame] | 141 | bool |
Steve Capper | 2667f50 | 2014-10-09 15:29:14 -0700 | [diff] [blame] | 142 | |
Tejun Heo | c378ddd | 2011-07-14 11:46:03 +0200 | [diff] [blame] | 143 | config ARCH_DISCARD_MEMBLOCK |
Christoph Jaeger | 6341e62 | 2014-12-20 15:41:11 -0500 | [diff] [blame] | 144 | bool |
Tejun Heo | c378ddd | 2011-07-14 11:46:03 +0200 | [diff] [blame] | 145 | |
Sam Ravnborg | 6661672 | 2011-10-31 17:08:20 -0700 | [diff] [blame] | 146 | config NO_BOOTMEM |
Christoph Jaeger | 6341e62 | 2014-12-20 15:41:11 -0500 | [diff] [blame] | 147 | bool |
Sam Ravnborg | 6661672 | 2011-10-31 17:08:20 -0700 | [diff] [blame] | 148 | |
Minchan Kim | ee6f509 | 2012-07-31 16:43:50 -0700 | [diff] [blame] | 149 | config MEMORY_ISOLATION |
Christoph Jaeger | 6341e62 | 2014-12-20 15:41:11 -0500 | [diff] [blame] | 150 | bool |
Minchan Kim | ee6f509 | 2012-07-31 16:43:50 -0700 | [diff] [blame] | 151 | |
Lai Jiangshan | 20b2f52 | 2012-12-12 13:52:00 -0800 | [diff] [blame] | 152 | config MOVABLE_NODE |
Christoph Jaeger | 6341e62 | 2014-12-20 15:41:11 -0500 | [diff] [blame] | 153 | bool "Enable to assign a node which has only movable memory" |
Lai Jiangshan | 20b2f52 | 2012-12-12 13:52:00 -0800 | [diff] [blame] | 154 | depends on HAVE_MEMBLOCK |
| 155 | depends on NO_BOOTMEM |
| 156 | depends on X86_64 |
| 157 | depends on NUMA |
Tang Chen | c297405 | 2012-12-18 14:21:33 -0800 | [diff] [blame] | 158 | default n |
| 159 | help |
| 160 | Allow a node to have only movable memory. Pages used by the kernel, |
| 161 | such as direct mapping pages cannot be migrated. So the corresponding |
Tang Chen | c532092 | 2013-11-12 15:08:10 -0800 | [diff] [blame] | 162 | memory device cannot be hotplugged. This option allows the following |
| 163 | two things: |
| 164 | - When the system is booting, node full of hotpluggable memory can |
| 165 | be arranged to have only movable memory so that the whole node can |
| 166 | be hot-removed. (need movable_node boot option specified). |
| 167 | - After the system is up, the option allows users to online all the |
| 168 | memory of a node as movable memory so that the whole node can be |
| 169 | hot-removed. |
| 170 | |
| 171 | Users who don't use the memory hotplug feature are fine with this |
| 172 | option on since they don't specify movable_node boot option or they |
| 173 | don't online memory as movable. |
Tang Chen | c297405 | 2012-12-18 14:21:33 -0800 | [diff] [blame] | 174 | |
| 175 | Say Y here if you want to hotplug a whole node. |
| 176 | Say N here if you want kernel to use memory on all nodes evenly. |
Lai Jiangshan | 20b2f52 | 2012-12-12 13:52:00 -0800 | [diff] [blame] | 177 | |
Yasuaki Ishimatsu | 46723bf | 2013-02-22 16:33:00 -0800 | [diff] [blame] | 178 | # |
| 179 | # Only be set on architectures that have completely implemented memory hotplug |
| 180 | # feature. If you are not sure, don't touch it. |
| 181 | # |
| 182 | config HAVE_BOOTMEM_INFO_NODE |
| 183 | def_bool n |
| 184 | |
Dave Hansen | 3947be1 | 2005-10-29 18:16:54 -0700 | [diff] [blame] | 185 | # eventually, we can have this option just 'select SPARSEMEM' |
| 186 | config MEMORY_HOTPLUG |
| 187 | bool "Allow for memory hot-add" |
Keith Mannthey | ec69acb | 2006-09-30 23:27:05 -0700 | [diff] [blame] | 188 | depends on SPARSEMEM || X86_64_ACPI_NUMA |
Stephen Rothwell | 40b3136 | 2013-05-21 13:49:35 +1000 | [diff] [blame] | 189 | depends on ARCH_ENABLE_MEMORY_HOTPLUG |
Kumar Gala | ed84a07 | 2009-10-16 07:21:36 +0000 | [diff] [blame] | 190 | depends on (IA64 || X86 || PPC_BOOK3S_64 || SUPERH || S390) |
Dave Hansen | 3947be1 | 2005-10-29 18:16:54 -0700 | [diff] [blame] | 191 | |
Keith Mannthey | ec69acb | 2006-09-30 23:27:05 -0700 | [diff] [blame] | 192 | config MEMORY_HOTPLUG_SPARSE |
| 193 | def_bool y |
| 194 | depends on SPARSEMEM && MEMORY_HOTPLUG |
| 195 | |
KAMEZAWA Hiroyuki | 0c0e619 | 2007-10-16 01:26:12 -0700 | [diff] [blame] | 196 | config MEMORY_HOTREMOVE |
| 197 | bool "Allow for memory hot remove" |
Yasuaki Ishimatsu | 46723bf | 2013-02-22 16:33:00 -0800 | [diff] [blame] | 198 | select MEMORY_ISOLATION |
Nathan Fontenot | f7e3334 | 2013-09-27 10:18:09 -0500 | [diff] [blame] | 199 | select HAVE_BOOTMEM_INFO_NODE if (X86_64 || PPC64) |
KAMEZAWA Hiroyuki | 0c0e619 | 2007-10-16 01:26:12 -0700 | [diff] [blame] | 200 | depends on MEMORY_HOTPLUG && ARCH_ENABLE_MEMORY_HOTREMOVE |
| 201 | depends on MIGRATION |
| 202 | |
Hugh Dickins | 4c21e2f | 2005-10-29 18:16:40 -0700 | [diff] [blame] | 203 | # Heavily threaded applications may benefit from splitting the mm-wide |
| 204 | # page_table_lock, so that faults on different parts of the user address |
| 205 | # space can be handled with less contention: split it at this NR_CPUS. |
| 206 | # Default to 4 for wider testing, though 8 might be more appropriate. |
| 207 | # ARM's adjust_pte (unused if VIPT) depends on mm-wide page_table_lock. |
Hugh Dickins | 7b6ac9d | 2005-11-23 13:37:37 -0800 | [diff] [blame] | 208 | # PA-RISC 7xxx's spinlock_t would enlarge struct page from 32 to 44 bytes. |
Hugh Dickins | a70caa8 | 2009-12-14 17:59:02 -0800 | [diff] [blame] | 209 | # DEBUG_SPINLOCK and DEBUG_LOCK_ALLOC spinlock_t also enlarge struct page. |
Hugh Dickins | 4c21e2f | 2005-10-29 18:16:40 -0700 | [diff] [blame] | 210 | # |
| 211 | config SPLIT_PTLOCK_CPUS |
| 212 | int |
Kirill A. Shutemov | 9164550 | 2014-04-07 15:37:14 -0700 | [diff] [blame] | 213 | default "999999" if !MMU |
Hugh Dickins | a70caa8 | 2009-12-14 17:59:02 -0800 | [diff] [blame] | 214 | default "999999" if ARM && !CPU_CACHE_VIPT |
| 215 | default "999999" if PARISC && !PA20 |
Hugh Dickins | 4c21e2f | 2005-10-29 18:16:40 -0700 | [diff] [blame] | 216 | default "4" |
Christoph Lameter | 7cbe34c | 2006-01-08 01:00:49 -0800 | [diff] [blame] | 217 | |
Kirill A. Shutemov | e009bb3 | 2013-11-14 14:31:07 -0800 | [diff] [blame] | 218 | config ARCH_ENABLE_SPLIT_PMD_PTLOCK |
Christoph Jaeger | 6341e62 | 2014-12-20 15:41:11 -0500 | [diff] [blame] | 219 | bool |
Kirill A. Shutemov | e009bb3 | 2013-11-14 14:31:07 -0800 | [diff] [blame] | 220 | |
Christoph Lameter | 7cbe34c | 2006-01-08 01:00:49 -0800 | [diff] [blame] | 221 | # |
Konstantin Khlebnikov | 09316c0 | 2014-10-09 15:29:32 -0700 | [diff] [blame] | 222 | # support for memory balloon |
| 223 | config MEMORY_BALLOON |
Christoph Jaeger | 6341e62 | 2014-12-20 15:41:11 -0500 | [diff] [blame] | 224 | bool |
Konstantin Khlebnikov | 09316c0 | 2014-10-09 15:29:32 -0700 | [diff] [blame] | 225 | |
| 226 | # |
Rafael Aquini | 18468d9 | 2012-12-11 16:02:38 -0800 | [diff] [blame] | 227 | # support for memory balloon compaction |
| 228 | config BALLOON_COMPACTION |
| 229 | bool "Allow for balloon memory compaction/migration" |
| 230 | def_bool y |
Konstantin Khlebnikov | 09316c0 | 2014-10-09 15:29:32 -0700 | [diff] [blame] | 231 | depends on COMPACTION && MEMORY_BALLOON |
Rafael Aquini | 18468d9 | 2012-12-11 16:02:38 -0800 | [diff] [blame] | 232 | help |
| 233 | Memory fragmentation introduced by ballooning might reduce |
| 234 | significantly the number of 2MB contiguous memory blocks that can be |
| 235 | used within a guest, thus imposing performance penalties associated |
| 236 | with the reduced number of transparent huge pages that could be used |
| 237 | by the guest workload. Allowing the compaction & migration for memory |
| 238 | pages enlisted as being part of memory balloon devices avoids the |
| 239 | scenario aforementioned and helps improving memory defragmentation. |
| 240 | |
| 241 | # |
Mel Gorman | e9e96b3 | 2010-05-24 14:32:21 -0700 | [diff] [blame] | 242 | # support for memory compaction |
| 243 | config COMPACTION |
| 244 | bool "Allow for memory compaction" |
Rik van Riel | 05106e6 | 2012-10-08 16:33:03 -0700 | [diff] [blame] | 245 | def_bool y |
Mel Gorman | e9e96b3 | 2010-05-24 14:32:21 -0700 | [diff] [blame] | 246 | select MIGRATION |
Andrea Arcangeli | 33a9387 | 2011-01-25 15:07:25 -0800 | [diff] [blame] | 247 | depends on MMU |
Mel Gorman | e9e96b3 | 2010-05-24 14:32:21 -0700 | [diff] [blame] | 248 | help |
| 249 | Allows the compaction of memory for the allocation of huge pages. |
| 250 | |
| 251 | # |
Christoph Lameter | 7cbe34c | 2006-01-08 01:00:49 -0800 | [diff] [blame] | 252 | # support for page migration |
| 253 | # |
| 254 | config MIGRATION |
Christoph Lameter | b20a350 | 2006-03-22 00:09:12 -0800 | [diff] [blame] | 255 | bool "Page migration" |
Christoph Lameter | 6c5240a | 2006-06-23 02:03:37 -0700 | [diff] [blame] | 256 | def_bool y |
Chen Gang | de32a81 | 2013-09-12 15:14:08 -0700 | [diff] [blame] | 257 | depends on (NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE || COMPACTION || CMA) && MMU |
Christoph Lameter | b20a350 | 2006-03-22 00:09:12 -0800 | [diff] [blame] | 258 | help |
| 259 | Allows the migration of the physical location of pages of processes |
Mel Gorman | e9e96b3 | 2010-05-24 14:32:21 -0700 | [diff] [blame] | 260 | while the virtual addresses are not changed. This is useful in |
| 261 | two situations. The first is on NUMA systems to put pages nearer |
| 262 | to the processors accessing. The second is when allocating huge |
| 263 | pages as migration can relocate pages to satisfy a huge page |
| 264 | allocation instead of reclaiming. |
Greg Kroah-Hartman | 6550e07 | 2006-06-12 17:11:31 -0700 | [diff] [blame] | 265 | |
Naoya Horiguchi | c177c81 | 2014-06-04 16:05:35 -0700 | [diff] [blame] | 266 | config ARCH_ENABLE_HUGEPAGE_MIGRATION |
Christoph Jaeger | 6341e62 | 2014-12-20 15:41:11 -0500 | [diff] [blame] | 267 | bool |
Naoya Horiguchi | c177c81 | 2014-06-04 16:05:35 -0700 | [diff] [blame] | 268 | |
Jeremy Fitzhardinge | 600715d | 2008-09-11 01:31:45 -0700 | [diff] [blame] | 269 | config PHYS_ADDR_T_64BIT |
| 270 | def_bool 64BIT || ARCH_PHYS_ADDR_T_64BIT |
| 271 | |
Christoph Lameter | 4b51d66 | 2007-02-10 01:43:10 -0800 | [diff] [blame] | 272 | config ZONE_DMA_FLAG |
| 273 | int |
| 274 | default "0" if !ZONE_DMA |
| 275 | default "1" |
| 276 | |
Christoph Lameter | 2a7326b | 2007-07-17 04:03:37 -0700 | [diff] [blame] | 277 | config BOUNCE |
Vinayak Menon | 9ca24e2 | 2013-04-29 15:08:55 -0700 | [diff] [blame] | 278 | bool "Enable bounce buffers" |
| 279 | default y |
Christoph Lameter | 2a7326b | 2007-07-17 04:03:37 -0700 | [diff] [blame] | 280 | depends on BLOCK && MMU && (ZONE_DMA || HIGHMEM) |
Vinayak Menon | 9ca24e2 | 2013-04-29 15:08:55 -0700 | [diff] [blame] | 281 | help |
| 282 | Enable bounce buffers for devices that cannot access |
| 283 | the full range of memory available to the CPU. Enabled |
| 284 | by default when ZONE_DMA or HIGHMEM is selected, but you |
| 285 | may say n to override this. |
Christoph Lameter | 2a7326b | 2007-07-17 04:03:37 -0700 | [diff] [blame] | 286 | |
Darrick J. Wong | ffecfd1 | 2013-02-21 16:42:55 -0800 | [diff] [blame] | 287 | # On the 'tile' arch, USB OHCI needs the bounce pool since tilegx will often |
| 288 | # have more than 4GB of memory, but we don't currently use the IOTLB to present |
| 289 | # a 32-bit address to OHCI. So we need to use a bounce pool instead. |
Darrick J. Wong | ffecfd1 | 2013-02-21 16:42:55 -0800 | [diff] [blame] | 290 | config NEED_BOUNCE_POOL |
| 291 | bool |
Valentin Rothberg | debeb29 | 2015-07-23 13:18:06 +0200 | [diff] [blame] | 292 | default y if TILE && USB_OHCI_HCD |
Darrick J. Wong | ffecfd1 | 2013-02-21 16:42:55 -0800 | [diff] [blame] | 293 | |
Christoph Lameter | 6225e93 | 2007-05-06 14:49:50 -0700 | [diff] [blame] | 294 | config NR_QUICK |
| 295 | int |
| 296 | depends on QUICKLIST |
Paul Mundt | 0176bd3 | 2010-01-05 12:35:00 +0900 | [diff] [blame] | 297 | default "2" if AVR32 |
Christoph Lameter | 6225e93 | 2007-05-06 14:49:50 -0700 | [diff] [blame] | 298 | default "1" |
Stephen Rothwell | f057eac | 2007-07-15 23:40:05 -0700 | [diff] [blame] | 299 | |
| 300 | config VIRT_TO_BUS |
Stephen Rothwell | 4febd95 | 2013-03-07 15:48:16 +1100 | [diff] [blame] | 301 | bool |
| 302 | help |
| 303 | An architecture should select this if it implements the |
| 304 | deprecated interface virt_to_bus(). All new architectures |
| 305 | should probably not select this. |
| 306 | |
Andrea Arcangeli | cddb8a5 | 2008-07-28 15:46:29 -0700 | [diff] [blame] | 307 | |
| 308 | config MMU_NOTIFIER |
| 309 | bool |
Pranith Kumar | 83fe27e | 2014-12-05 11:24:45 -0500 | [diff] [blame] | 310 | select SRCU |
David Howells | fc4d5c2 | 2009-05-06 16:03:05 -0700 | [diff] [blame] | 311 | |
Hugh Dickins | f8af4da | 2009-09-21 17:01:57 -0700 | [diff] [blame] | 312 | config KSM |
| 313 | bool "Enable KSM for page merging" |
| 314 | depends on MMU |
| 315 | help |
| 316 | Enable Kernel Samepage Merging: KSM periodically scans those areas |
| 317 | of an application's address space that an app has advised may be |
| 318 | mergeable. When it finds pages of identical content, it replaces |
Hugh Dickins | d0f209f | 2009-12-14 17:59:34 -0800 | [diff] [blame] | 319 | the many instances by a single page with that content, so |
Hugh Dickins | f8af4da | 2009-09-21 17:01:57 -0700 | [diff] [blame] | 320 | saving memory until one or another app needs to modify the content. |
| 321 | Recommended for use with KVM, or with other duplicative applications. |
Hugh Dickins | c73602a | 2009-10-07 16:32:22 -0700 | [diff] [blame] | 322 | See Documentation/vm/ksm.txt for more information: KSM is inactive |
| 323 | until a program has madvised that an area is MADV_MERGEABLE, and |
| 324 | root has set /sys/kernel/mm/ksm/run to 1 (if CONFIG_SYSFS is set). |
Hugh Dickins | f8af4da | 2009-09-21 17:01:57 -0700 | [diff] [blame] | 325 | |
Christoph Lameter | e0a94c2 | 2009-06-03 16:04:31 -0400 | [diff] [blame] | 326 | config DEFAULT_MMAP_MIN_ADDR |
| 327 | int "Low address space to protect from user allocation" |
David Howells | 6e14154 | 2009-12-15 19:27:45 +0000 | [diff] [blame] | 328 | depends on MMU |
Christoph Lameter | e0a94c2 | 2009-06-03 16:04:31 -0400 | [diff] [blame] | 329 | default 4096 |
| 330 | help |
| 331 | This is the portion of low virtual memory which should be protected |
| 332 | from userspace allocation. Keeping a user from writing to low pages |
| 333 | can help reduce the impact of kernel NULL pointer bugs. |
| 334 | |
| 335 | For most ia64, ppc64 and x86 users with lots of address space |
| 336 | a value of 65536 is reasonable and should cause no problems. |
| 337 | On arm and other archs it should not be higher than 32768. |
Eric Paris | 788084a | 2009-07-31 12:54:11 -0400 | [diff] [blame] | 338 | Programs which use vm86 functionality or have some need to map |
| 339 | this low address space will need CAP_SYS_RAWIO or disable this |
| 340 | protection by setting the value to 0. |
Christoph Lameter | e0a94c2 | 2009-06-03 16:04:31 -0400 | [diff] [blame] | 341 | |
| 342 | This value can be changed after boot using the |
| 343 | /proc/sys/vm/mmap_min_addr tunable. |
| 344 | |
Linus Torvalds | d949f36 | 2009-09-26 09:35:07 -0700 | [diff] [blame] | 345 | config ARCH_SUPPORTS_MEMORY_FAILURE |
| 346 | bool |
Christoph Lameter | e0a94c2 | 2009-06-03 16:04:31 -0400 | [diff] [blame] | 347 | |
Andi Kleen | 6a46079 | 2009-09-16 11:50:15 +0200 | [diff] [blame] | 348 | config MEMORY_FAILURE |
| 349 | depends on MMU |
Linus Torvalds | d949f36 | 2009-09-26 09:35:07 -0700 | [diff] [blame] | 350 | depends on ARCH_SUPPORTS_MEMORY_FAILURE |
Andi Kleen | 6a46079 | 2009-09-16 11:50:15 +0200 | [diff] [blame] | 351 | bool "Enable recovery from hardware memory errors" |
Minchan Kim | ee6f509 | 2012-07-31 16:43:50 -0700 | [diff] [blame] | 352 | select MEMORY_ISOLATION |
Xie XiuQi | 97f0b13 | 2015-06-24 16:57:36 -0700 | [diff] [blame] | 353 | select RAS |
Andi Kleen | 6a46079 | 2009-09-16 11:50:15 +0200 | [diff] [blame] | 354 | help |
| 355 | Enables code to recover from some memory failures on systems |
| 356 | with MCA recovery. This allows a system to continue running |
| 357 | even when some of its memory has uncorrected errors. This requires |
| 358 | special hardware support and typically ECC memory. |
| 359 | |
Andi Kleen | cae681f | 2009-09-16 11:50:17 +0200 | [diff] [blame] | 360 | config HWPOISON_INJECT |
Andi Kleen | 413f9ef | 2009-12-16 12:20:00 +0100 | [diff] [blame] | 361 | tristate "HWPoison pages injector" |
Andi Kleen | 27df506 | 2009-12-21 19:56:42 +0100 | [diff] [blame] | 362 | depends on MEMORY_FAILURE && DEBUG_KERNEL && PROC_FS |
Wu Fengguang | 478c5ff | 2009-12-16 12:19:59 +0100 | [diff] [blame] | 363 | select PROC_PAGE_MONITOR |
Andi Kleen | cae681f | 2009-09-16 11:50:17 +0200 | [diff] [blame] | 364 | |
David Howells | fc4d5c2 | 2009-05-06 16:03:05 -0700 | [diff] [blame] | 365 | config NOMMU_INITIAL_TRIM_EXCESS |
| 366 | int "Turn on mmap() excess space trimming before booting" |
| 367 | depends on !MMU |
| 368 | default 1 |
| 369 | help |
| 370 | The NOMMU mmap() frequently needs to allocate large contiguous chunks |
| 371 | of memory on which to store mappings, but it can only ask the system |
| 372 | allocator for chunks in 2^N*PAGE_SIZE amounts - which is frequently |
| 373 | more than it requires. To deal with this, mmap() is able to trim off |
| 374 | the excess and return it to the allocator. |
| 375 | |
| 376 | If trimming is enabled, the excess is trimmed off and returned to the |
| 377 | system allocator, which can cause extra fragmentation, particularly |
| 378 | if there are a lot of transient processes. |
| 379 | |
| 380 | If trimming is disabled, the excess is kept, but not used, which for |
| 381 | long-term mappings means that the space is wasted. |
| 382 | |
| 383 | Trimming can be dynamically controlled through a sysctl option |
| 384 | (/proc/sys/vm/nr_trim_pages) which specifies the minimum number of |
| 385 | excess pages there must be before trimming should occur, or zero if |
| 386 | no trimming is to occur. |
| 387 | |
| 388 | This option specifies the initial value of this option. The default |
| 389 | of 1 says that all excess pages should be trimmed. |
| 390 | |
| 391 | See Documentation/nommu-mmap.txt for more information. |
Tejun Heo | bbddff0 | 2010-09-03 18:22:48 +0200 | [diff] [blame] | 392 | |
Andrea Arcangeli | 4c76d9d | 2011-01-13 15:46:39 -0800 | [diff] [blame] | 393 | config TRANSPARENT_HUGEPAGE |
Andrea Arcangeli | 13ece88 | 2011-01-13 15:47:07 -0800 | [diff] [blame] | 394 | bool "Transparent Hugepage Support" |
Gerald Schaefer | 1562606 | 2012-10-08 16:30:04 -0700 | [diff] [blame] | 395 | depends on HAVE_ARCH_TRANSPARENT_HUGEPAGE |
Andrea Arcangeli | 5d68924 | 2011-01-13 15:47:07 -0800 | [diff] [blame] | 396 | select COMPACTION |
Andrea Arcangeli | 4c76d9d | 2011-01-13 15:46:39 -0800 | [diff] [blame] | 397 | help |
| 398 | Transparent Hugepages allows the kernel to use huge pages and |
| 399 | huge tlb transparently to the applications whenever possible. |
| 400 | This feature can improve computing performance to certain |
| 401 | applications by speeding up page faults during memory |
| 402 | allocation, by reducing the number of tlb misses and by speeding |
| 403 | up the pagetable walking. |
| 404 | |
| 405 | If memory constrained on embedded, you may want to say N. |
| 406 | |
Andrea Arcangeli | 13ece88 | 2011-01-13 15:47:07 -0800 | [diff] [blame] | 407 | choice |
| 408 | prompt "Transparent Hugepage Support sysfs defaults" |
| 409 | depends on TRANSPARENT_HUGEPAGE |
| 410 | default TRANSPARENT_HUGEPAGE_ALWAYS |
| 411 | help |
| 412 | Selects the sysfs defaults for Transparent Hugepage Support. |
| 413 | |
| 414 | config TRANSPARENT_HUGEPAGE_ALWAYS |
| 415 | bool "always" |
| 416 | help |
| 417 | Enabling Transparent Hugepage always, can increase the |
| 418 | memory footprint of applications without a guaranteed |
| 419 | benefit but it will work automatically for all applications. |
| 420 | |
| 421 | config TRANSPARENT_HUGEPAGE_MADVISE |
| 422 | bool "madvise" |
| 423 | help |
| 424 | Enabling Transparent Hugepage madvise, will only provide a |
| 425 | performance improvement benefit to the applications using |
| 426 | madvise(MADV_HUGEPAGE) but it won't risk to increase the |
| 427 | memory footprint of applications without a guaranteed |
| 428 | benefit. |
| 429 | endchoice |
| 430 | |
Tejun Heo | bbddff0 | 2010-09-03 18:22:48 +0200 | [diff] [blame] | 431 | # |
| 432 | # UP and nommu archs use km based percpu allocator |
| 433 | # |
| 434 | config NEED_PER_CPU_KM |
| 435 | depends on !SMP |
| 436 | bool |
| 437 | default y |
Dan Magenheimer | 077b1f8 | 2011-05-26 10:01:36 -0600 | [diff] [blame] | 438 | |
| 439 | config CLEANCACHE |
| 440 | bool "Enable cleancache driver to cache clean pages if tmem is present" |
| 441 | default n |
| 442 | help |
| 443 | Cleancache can be thought of as a page-granularity victim cache |
| 444 | for clean pages that the kernel's pageframe replacement algorithm |
| 445 | (PFRA) would like to keep around, but can't since there isn't enough |
| 446 | memory. So when the PFRA "evicts" a page, it first attempts to use |
Michael Witten | 140a1ef | 2011-06-10 03:57:26 +0000 | [diff] [blame] | 447 | cleancache code to put the data contained in that page into |
Dan Magenheimer | 077b1f8 | 2011-05-26 10:01:36 -0600 | [diff] [blame] | 448 | "transcendent memory", memory that is not directly accessible or |
| 449 | addressable by the kernel and is of unknown and possibly |
| 450 | time-varying size. And when a cleancache-enabled |
| 451 | filesystem wishes to access a page in a file on disk, it first |
| 452 | checks cleancache to see if it already contains it; if it does, |
| 453 | the page is copied into the kernel and a disk access is avoided. |
| 454 | When a transcendent memory driver is available (such as zcache or |
| 455 | Xen transcendent memory), a significant I/O reduction |
| 456 | may be achieved. When none is available, all cleancache calls |
| 457 | are reduced to a single pointer-compare-against-NULL resulting |
| 458 | in a negligible performance hit. |
| 459 | |
| 460 | If unsure, say Y to enable cleancache |
Dan Magenheimer | 27c6aec | 2012-04-09 17:10:34 -0600 | [diff] [blame] | 461 | |
| 462 | config FRONTSWAP |
| 463 | bool "Enable frontswap to cache swap pages if tmem is present" |
| 464 | depends on SWAP |
| 465 | default n |
| 466 | help |
| 467 | Frontswap is so named because it can be thought of as the opposite |
| 468 | of a "backing" store for a swap device. The data is stored into |
| 469 | "transcendent memory", memory that is not directly accessible or |
| 470 | addressable by the kernel and is of unknown and possibly |
| 471 | time-varying size. When space in transcendent memory is available, |
| 472 | a significant swap I/O reduction may be achieved. When none is |
| 473 | available, all frontswap calls are reduced to a single pointer- |
| 474 | compare-against-NULL resulting in a negligible performance hit |
| 475 | and swap data is stored as normal on the matching swap device. |
| 476 | |
| 477 | If unsure, say Y to enable frontswap. |
Aneesh Kumar K.V | f825c73 | 2013-07-02 11:15:15 +0530 | [diff] [blame] | 478 | |
| 479 | config CMA |
| 480 | bool "Contiguous Memory Allocator" |
Chen Gang | de32a81 | 2013-09-12 15:14:08 -0700 | [diff] [blame] | 481 | depends on HAVE_MEMBLOCK && MMU |
Aneesh Kumar K.V | f825c73 | 2013-07-02 11:15:15 +0530 | [diff] [blame] | 482 | select MIGRATION |
| 483 | select MEMORY_ISOLATION |
| 484 | help |
| 485 | This enables the Contiguous Memory Allocator which allows other |
| 486 | subsystems to allocate big physically-contiguous blocks of memory. |
| 487 | CMA reserves a region of memory and allows only movable pages to |
| 488 | be allocated from it. This way, the kernel can use the memory for |
| 489 | pagecache and when a subsystem requests for contiguous area, the |
| 490 | allocated pages are migrated away to serve the contiguous request. |
| 491 | |
| 492 | If unsure, say "n". |
| 493 | |
| 494 | config CMA_DEBUG |
| 495 | bool "CMA debug messages (DEVELOPMENT)" |
| 496 | depends on DEBUG_KERNEL && CMA |
| 497 | help |
| 498 | Turns on debug messages in CMA. This produces KERN_DEBUG |
| 499 | messages for every CMA call as well as various messages while |
| 500 | processing calls such as dma_alloc_from_contiguous(). |
| 501 | This option does not affect warning and error messages. |
Alexander Graf | bf550fc | 2013-08-29 00:41:59 +0200 | [diff] [blame] | 502 | |
Sasha Levin | 28b24c1 | 2015-04-14 15:44:57 -0700 | [diff] [blame] | 503 | config CMA_DEBUGFS |
| 504 | bool "CMA debugfs interface" |
| 505 | depends on CMA && DEBUG_FS |
| 506 | help |
| 507 | Turns on the DebugFS interface for CMA. |
| 508 | |
Joonsoo Kim | a254129 | 2014-08-06 16:05:25 -0700 | [diff] [blame] | 509 | config CMA_AREAS |
| 510 | int "Maximum count of the CMA areas" |
| 511 | depends on CMA |
| 512 | default 7 |
| 513 | help |
| 514 | CMA allows to create CMA areas for particular purpose, mainly, |
| 515 | used as device private area. This parameter sets the maximum |
| 516 | number of CMA area in the system. |
| 517 | |
| 518 | If unsure, leave the default value "7". |
| 519 | |
Dan Streetman | af8d417 | 2014-08-06 16:08:36 -0700 | [diff] [blame] | 520 | config MEM_SOFT_DIRTY |
| 521 | bool "Track memory changes" |
| 522 | depends on CHECKPOINT_RESTORE && HAVE_ARCH_SOFT_DIRTY && PROC_FS |
| 523 | select PROC_PAGE_MONITOR |
Seth Jennings | 4e2e277 | 2013-07-10 16:04:55 -0700 | [diff] [blame] | 524 | help |
Dan Streetman | af8d417 | 2014-08-06 16:08:36 -0700 | [diff] [blame] | 525 | This option enables memory changes tracking by introducing a |
| 526 | soft-dirty bit on pte-s. This bit it set when someone writes |
| 527 | into a page just as regular dirty bit, but unlike the latter |
| 528 | it can be cleared by hands. |
| 529 | |
| 530 | See Documentation/vm/soft-dirty.txt for more details. |
Seth Jennings | 4e2e277 | 2013-07-10 16:04:55 -0700 | [diff] [blame] | 531 | |
Seth Jennings | 2b28111 | 2013-07-10 16:05:03 -0700 | [diff] [blame] | 532 | config ZSWAP |
| 533 | bool "Compressed cache for swap pages (EXPERIMENTAL)" |
| 534 | depends on FRONTSWAP && CRYPTO=y |
| 535 | select CRYPTO_LZO |
Dan Streetman | 12d79d6 | 2014-08-06 16:08:40 -0700 | [diff] [blame] | 536 | select ZPOOL |
Seth Jennings | 2b28111 | 2013-07-10 16:05:03 -0700 | [diff] [blame] | 537 | default n |
| 538 | help |
| 539 | A lightweight compressed cache for swap pages. It takes |
| 540 | pages that are in the process of being swapped out and attempts to |
| 541 | compress them into a dynamically allocated RAM-based memory pool. |
| 542 | This can result in a significant I/O reduction on swap device and, |
| 543 | in the case where decompressing from RAM is faster that swap device |
| 544 | reads, can also improve workload performance. |
| 545 | |
| 546 | This is marked experimental because it is a new feature (as of |
| 547 | v3.11) that interacts heavily with memory reclaim. While these |
| 548 | interactions don't cause any known issues on simple memory setups, |
| 549 | they have not be fully explored on the large set of potential |
| 550 | configurations and workloads that exist. |
| 551 | |
Dan Streetman | af8d417 | 2014-08-06 16:08:36 -0700 | [diff] [blame] | 552 | config ZPOOL |
| 553 | tristate "Common API for compressed memory storage" |
| 554 | default n |
Pavel Emelyanov | 0f8975e | 2013-07-03 15:01:20 -0700 | [diff] [blame] | 555 | help |
Dan Streetman | af8d417 | 2014-08-06 16:08:36 -0700 | [diff] [blame] | 556 | Compressed memory storage API. This allows using either zbud or |
| 557 | zsmalloc. |
Pavel Emelyanov | 0f8975e | 2013-07-03 15:01:20 -0700 | [diff] [blame] | 558 | |
Dan Streetman | af8d417 | 2014-08-06 16:08:36 -0700 | [diff] [blame] | 559 | config ZBUD |
| 560 | tristate "Low density storage for compressed pages" |
| 561 | default n |
| 562 | help |
| 563 | A special purpose allocator for storing compressed pages. |
| 564 | It is designed to store up to two compressed pages per physical |
| 565 | page. While this design limits storage density, it has simple and |
| 566 | deterministic reclaim properties that make it preferable to a higher |
| 567 | density approach when reclaim will be used. |
Minchan Kim | bcf1647 | 2014-01-30 15:45:50 -0800 | [diff] [blame] | 568 | |
| 569 | config ZSMALLOC |
Minchan Kim | d867f20 | 2014-06-04 16:11:10 -0700 | [diff] [blame] | 570 | tristate "Memory allocator for compressed pages" |
Minchan Kim | bcf1647 | 2014-01-30 15:45:50 -0800 | [diff] [blame] | 571 | depends on MMU |
| 572 | default n |
| 573 | help |
| 574 | zsmalloc is a slab-based memory allocator designed to store |
| 575 | compressed RAM pages. zsmalloc uses virtual memory mapping |
| 576 | in order to reduce fragmentation. However, this results in a |
| 577 | non-standard allocator interface where a handle, not a pointer, is |
| 578 | returned by an alloc(). This handle must be mapped in order to |
| 579 | access the allocated space. |
| 580 | |
| 581 | config PGTABLE_MAPPING |
| 582 | bool "Use page table mapping to access object in zsmalloc" |
| 583 | depends on ZSMALLOC |
| 584 | help |
| 585 | By default, zsmalloc uses a copy-based object mapping method to |
| 586 | access allocations that span two pages. However, if a particular |
| 587 | architecture (ex, ARM) performs VM mapping faster than copying, |
| 588 | then you should select this. This causes zsmalloc to use page table |
| 589 | mapping rather than copying for object mapping. |
| 590 | |
Ben Hutchings | 2216ee8 | 2014-03-10 15:49:46 -0700 | [diff] [blame] | 591 | You can check speed with zsmalloc benchmark: |
| 592 | https://github.com/spartacus06/zsmapbench |
Mark Salter | 9e5c33d | 2014-04-07 15:39:48 -0700 | [diff] [blame] | 593 | |
Ganesh Mahendran | 0f050d9 | 2015-02-12 15:00:54 -0800 | [diff] [blame] | 594 | config ZSMALLOC_STAT |
| 595 | bool "Export zsmalloc statistics" |
| 596 | depends on ZSMALLOC |
| 597 | select DEBUG_FS |
| 598 | help |
| 599 | This option enables code in the zsmalloc to collect various |
| 600 | statistics about whats happening in zsmalloc and exports that |
| 601 | information to userspace via debugfs. |
| 602 | If unsure, say N. |
| 603 | |
Mark Salter | 9e5c33d | 2014-04-07 15:39:48 -0700 | [diff] [blame] | 604 | config GENERIC_EARLY_IOREMAP |
| 605 | bool |
Helge Deller | 042d27a | 2014-04-30 23:26:02 +0200 | [diff] [blame] | 606 | |
| 607 | config MAX_STACK_SIZE_MB |
| 608 | int "Maximum user stack size for 32-bit processes (MB)" |
| 609 | default 80 |
| 610 | range 8 256 if METAG |
| 611 | range 8 2048 |
| 612 | depends on STACK_GROWSUP && (!64BIT || COMPAT) |
| 613 | help |
| 614 | This is the maximum stack size in Megabytes in the VM layout of 32-bit |
| 615 | user processes when the stack grows upwards (currently only on parisc |
| 616 | and metag arch). The stack will be located at the highest memory |
| 617 | address minus the given value, unless the RLIMIT_STACK hard limit is |
| 618 | changed to a smaller value in which case that is used. |
| 619 | |
| 620 | A sane initial value is 80 MB. |
Mel Gorman | 3a80a7f | 2015-06-30 14:57:02 -0700 | [diff] [blame] | 621 | |
| 622 | # For architectures that support deferred memory initialisation |
| 623 | config ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT |
| 624 | bool |
| 625 | |
| 626 | config DEFERRED_STRUCT_PAGE_INIT |
Vlastimil Babka | 1ce2210 | 2016-02-05 15:36:21 -0800 | [diff] [blame] | 627 | bool "Defer initialisation of struct pages to kthreads" |
Mel Gorman | 3a80a7f | 2015-06-30 14:57:02 -0700 | [diff] [blame] | 628 | default n |
| 629 | depends on ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT |
| 630 | depends on MEMORY_HOTPLUG |
| 631 | help |
| 632 | Ordinarily all struct pages are initialised during early boot in a |
| 633 | single thread. On very large machines this can take a considerable |
| 634 | amount of time. If this option is set, large machines will bring up |
| 635 | a subset of memmap at boot and then initialise the rest in parallel |
Vlastimil Babka | 1ce2210 | 2016-02-05 15:36:21 -0800 | [diff] [blame] | 636 | by starting one-off "pgdatinitX" kernel thread for each node X. This |
| 637 | has a potential performance impact on processes running early in the |
| 638 | lifetime of the system until these kthreads finish the |
| 639 | initialisation. |
Dan Williams | 033fbae | 2015-08-09 15:29:06 -0400 | [diff] [blame] | 640 | |
Vladimir Davydov | 33c3fc7 | 2015-09-09 15:35:45 -0700 | [diff] [blame] | 641 | config IDLE_PAGE_TRACKING |
| 642 | bool "Enable idle page tracking" |
| 643 | depends on SYSFS && MMU |
| 644 | select PAGE_EXTENSION if !64BIT |
| 645 | help |
| 646 | This feature allows to estimate the amount of user pages that have |
| 647 | not been touched during a given period of time. This information can |
| 648 | be useful to tune memory cgroup limits and/or for job placement |
| 649 | within a compute cluster. |
| 650 | |
| 651 | See Documentation/vm/idle_page_tracking.txt for more details. |
| 652 | |
Dan Williams | 033fbae | 2015-08-09 15:29:06 -0400 | [diff] [blame] | 653 | config ZONE_DEVICE |
| 654 | bool "Device memory (pmem, etc...) hotplug support" if EXPERT |
| 655 | default !ZONE_DMA |
| 656 | depends on !ZONE_DMA |
| 657 | depends on MEMORY_HOTPLUG |
| 658 | depends on MEMORY_HOTREMOVE |
| 659 | depends on X86_64 #arch_add_memory() comprehends device memory |
| 660 | |
| 661 | help |
| 662 | Device memory hotplug support allows for establishing pmem, |
| 663 | or other device driver discovered memory regions, in the |
| 664 | memmap. This allows pfn_to_page() lookups of otherwise |
| 665 | "device-physical" addresses which is needed for using a DAX |
| 666 | mapping in an O_DIRECT operation, among other things. |
| 667 | |
| 668 | If FS_DAX is enabled, then say Y. |
Linus Torvalds | 06a660a | 2015-09-11 16:42:39 -0700 | [diff] [blame] | 669 | |
Jan Kara | 8025e5d | 2015-07-13 11:55:44 -0300 | [diff] [blame] | 670 | config FRAME_VECTOR |
| 671 | bool |