[RAMEN9610-12171] mm: hpa: change allocate logic from buddy
[GitHub/LineageOS/android_kernel_motorola_exynos9610.git] / mm / Kconfig
CommitLineData
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1config SELECT_MEMORY_MODEL
2 def_bool y
a8826eeb 3 depends on ARCH_SELECT_MEMORY_MODEL
e1785e85 4
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5choice
6 prompt "Memory model"
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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
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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
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21 Some users of more advanced features like NUMA and
22 memory hotplug may have different options here.
18f65332 23 DISCONTIGMEM is a more mature, better tested system,
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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"
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33 depends on ARCH_DISCONTIGMEM_ENABLE
34 help
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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
ad3d0a38 40 can have degraded performance from the extra overhead that
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41 this option imposes.
42
43 Many NUMA configurations will have this as the only option.
44
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45 If unsure, choose "Flat Memory" over this option.
46
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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
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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
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62endchoice
63
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64config DISCONTIGMEM
65 def_bool y
66 depends on (!SELECT_MEMORY_MODEL && ARCH_DISCONTIGMEM_ENABLE) || DISCONTIGMEM_MANUAL
67
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68config SPARSEMEM
69 def_bool y
1a83e175 70 depends on (!SELECT_MEMORY_MODEL && ARCH_SPARSEMEM_ENABLE) || SPARSEMEM_MANUAL
d41dee36 71
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72config FLATMEM
73 def_bool y
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74 depends on (!DISCONTIGMEM && !SPARSEMEM) || FLATMEM_MANUAL
75
76config FLAT_NODE_MEM_MAP
77 def_bool y
78 depends on !SPARSEMEM
e1785e85 79
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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
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88
89config HAVE_MEMORY_PRESENT
90 def_bool y
d41dee36 91 depends on ARCH_HAVE_MEMORY_PRESENT || SPARSEMEM
802f192e 92
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93#
94# SPARSEMEM_EXTREME (which is the default) does some bootmem
84eb8d06 95# allocations when memory_present() is called. If this cannot
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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
9ba16087 104 bool
3e347261 105
802f192e 106#
44c09201 107# Architecture platforms which require a two level mem_section in SPARSEMEM
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108# must select this option. This is usually for architecture platforms with
109# an extremely sparse physical address space.
110#
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111config SPARSEMEM_EXTREME
112 def_bool y
113 depends on SPARSEMEM && !SPARSEMEM_STATIC
4c21e2f2 114
29c71111 115config SPARSEMEM_VMEMMAP_ENABLE
9ba16087 116 bool
29c71111 117
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118config SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
119 def_bool y
120 depends on SPARSEMEM && X86_64
121
29c71111 122config SPARSEMEM_VMEMMAP
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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.
29c71111 130
95f72d1e 131config HAVE_MEMBLOCK
6341e62b 132 bool
95f72d1e 133
7c0caeb8 134config HAVE_MEMBLOCK_NODE_MAP
6341e62b 135 bool
7c0caeb8 136
70210ed9 137config HAVE_MEMBLOCK_PHYS_MAP
6341e62b 138 bool
70210ed9 139
e585513b 140config HAVE_GENERIC_GUP
6341e62b 141 bool
2667f50e 142
c378ddd5 143config ARCH_DISCARD_MEMBLOCK
6341e62b 144 bool
c378ddd5 145
66616720 146config NO_BOOTMEM
6341e62b 147 bool
66616720 148
ee6f509c 149config MEMORY_ISOLATION
6341e62b 150 bool
ee6f509c 151
46723bfa
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152#
153# Only be set on architectures that have completely implemented memory hotplug
154# feature. If you are not sure, don't touch it.
155#
156config HAVE_BOOTMEM_INFO_NODE
157 def_bool n
158
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159# eventually, we can have this option just 'select SPARSEMEM'
160config MEMORY_HOTPLUG
161 bool "Allow for memory hot-add"
ec69acbb 162 depends on SPARSEMEM || X86_64_ACPI_NUMA
40b31360 163 depends on ARCH_ENABLE_MEMORY_HOTPLUG
3947be19 164
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165config MEMORY_HOTPLUG_SPARSE
166 def_bool y
167 depends on SPARSEMEM && MEMORY_HOTPLUG
168
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169config MEMORY_HOTPLUG_DEFAULT_ONLINE
170 bool "Online the newly added memory blocks by default"
171 default n
172 depends on MEMORY_HOTPLUG
173 help
174 This option sets the default policy setting for memory hotplug
175 onlining policy (/sys/devices/system/memory/auto_online_blocks) which
176 determines what happens to newly added memory regions. Policy setting
177 can always be changed at runtime.
178 See Documentation/memory-hotplug.txt for more information.
179
180 Say Y here if you want all hot-plugged memory blocks to appear in
181 'online' state by default.
182 Say N here if you want the default policy to keep all hot-plugged
183 memory blocks in 'offline' state.
184
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185config MEMORY_HOTREMOVE
186 bool "Allow for memory hot remove"
46723bfa 187 select MEMORY_ISOLATION
f7e3334a 188 select HAVE_BOOTMEM_INFO_NODE if (X86_64 || PPC64)
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189 depends on MEMORY_HOTPLUG && ARCH_ENABLE_MEMORY_HOTREMOVE
190 depends on MIGRATION
191
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192# Heavily threaded applications may benefit from splitting the mm-wide
193# page_table_lock, so that faults on different parts of the user address
194# space can be handled with less contention: split it at this NR_CPUS.
195# Default to 4 for wider testing, though 8 might be more appropriate.
196# ARM's adjust_pte (unused if VIPT) depends on mm-wide page_table_lock.
7b6ac9df 197# PA-RISC 7xxx's spinlock_t would enlarge struct page from 32 to 44 bytes.
a70caa8b 198# DEBUG_SPINLOCK and DEBUG_LOCK_ALLOC spinlock_t also enlarge struct page.
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199#
200config SPLIT_PTLOCK_CPUS
201 int
9164550e 202 default "999999" if !MMU
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203 default "999999" if ARM && !CPU_CACHE_VIPT
204 default "999999" if PARISC && !PA20
4c21e2f2 205 default "4"
7cbe34cf 206
e009bb30 207config ARCH_ENABLE_SPLIT_PMD_PTLOCK
6341e62b 208 bool
e009bb30 209
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210#
211# support for memory balloon
212config MEMORY_BALLOON
6341e62b 213 bool
09316c09 214
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215#
216# support for memory balloon compaction
217config BALLOON_COMPACTION
218 bool "Allow for balloon memory compaction/migration"
219 def_bool y
09316c09 220 depends on COMPACTION && MEMORY_BALLOON
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221 help
222 Memory fragmentation introduced by ballooning might reduce
223 significantly the number of 2MB contiguous memory blocks that can be
224 used within a guest, thus imposing performance penalties associated
225 with the reduced number of transparent huge pages that could be used
226 by the guest workload. Allowing the compaction & migration for memory
227 pages enlisted as being part of memory balloon devices avoids the
228 scenario aforementioned and helps improving memory defragmentation.
229
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230#
231# support for memory compaction
232config COMPACTION
233 bool "Allow for memory compaction"
05106e6a 234 def_bool y
e9e96b39 235 select MIGRATION
33a93877 236 depends on MMU
e9e96b39 237 help
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238 Compaction is the only memory management component to form
239 high order (larger physically contiguous) memory blocks
240 reliably. The page allocator relies on compaction heavily and
241 the lack of the feature can lead to unexpected OOM killer
242 invocations for high order memory requests. You shouldn't
243 disable this option unless there really is a strong reason for
244 it and then we would be really interested to hear about that at
245 linux-mm@kvack.org.
e9e96b39 246
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247#
248# support for page migration
249#
250config MIGRATION
b20a3503 251 bool "Page migration"
6c5240ae 252 def_bool y
de32a817 253 depends on (NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE || COMPACTION || CMA) && MMU
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254 help
255 Allows the migration of the physical location of pages of processes
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256 while the virtual addresses are not changed. This is useful in
257 two situations. The first is on NUMA systems to put pages nearer
258 to the processors accessing. The second is when allocating huge
259 pages as migration can relocate pages to satisfy a huge page
260 allocation instead of reclaiming.
6550e07f 261
c177c81e 262config ARCH_ENABLE_HUGEPAGE_MIGRATION
6341e62b 263 bool
c177c81e 264
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265config ARCH_ENABLE_THP_MIGRATION
266 bool
267
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268config PHYS_ADDR_T_64BIT
269 def_bool 64BIT || ARCH_PHYS_ADDR_T_64BIT
270
2a7326b5 271config BOUNCE
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272 bool "Enable bounce buffers"
273 default y
2a7326b5 274 depends on BLOCK && MMU && (ZONE_DMA || HIGHMEM)
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275 help
276 Enable bounce buffers for devices that cannot access
277 the full range of memory available to the CPU. Enabled
278 by default when ZONE_DMA or HIGHMEM is selected, but you
279 may say n to override this.
2a7326b5 280
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281# On the 'tile' arch, USB OHCI needs the bounce pool since tilegx will often
282# have more than 4GB of memory, but we don't currently use the IOTLB to present
283# a 32-bit address to OHCI. So we need to use a bounce pool instead.
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284config NEED_BOUNCE_POOL
285 bool
debeb297 286 default y if TILE && USB_OHCI_HCD
ffecfd1a 287
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288config NR_QUICK
289 int
290 depends on QUICKLIST
291 default "1"
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292
293config VIRT_TO_BUS
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294 bool
295 help
296 An architecture should select this if it implements the
297 deprecated interface virt_to_bus(). All new architectures
298 should probably not select this.
299
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300
301config MMU_NOTIFIER
302 bool
83fe27ea 303 select SRCU
fc4d5c29 304
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305config KSM
306 bool "Enable KSM for page merging"
307 depends on MMU
308 help
309 Enable Kernel Samepage Merging: KSM periodically scans those areas
310 of an application's address space that an app has advised may be
311 mergeable. When it finds pages of identical content, it replaces
d0f209f6 312 the many instances by a single page with that content, so
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313 saving memory until one or another app needs to modify the content.
314 Recommended for use with KVM, or with other duplicative applications.
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315 See Documentation/vm/ksm.txt for more information: KSM is inactive
316 until a program has madvised that an area is MADV_MERGEABLE, and
317 root has set /sys/kernel/mm/ksm/run to 1 (if CONFIG_SYSFS is set).
f8af4da3 318
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319config DEFAULT_MMAP_MIN_ADDR
320 int "Low address space to protect from user allocation"
6e141546 321 depends on MMU
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322 default 4096
323 help
324 This is the portion of low virtual memory which should be protected
325 from userspace allocation. Keeping a user from writing to low pages
326 can help reduce the impact of kernel NULL pointer bugs.
327
328 For most ia64, ppc64 and x86 users with lots of address space
329 a value of 65536 is reasonable and should cause no problems.
330 On arm and other archs it should not be higher than 32768.
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331 Programs which use vm86 functionality or have some need to map
332 this low address space will need CAP_SYS_RAWIO or disable this
333 protection by setting the value to 0.
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334
335 This value can be changed after boot using the
336 /proc/sys/vm/mmap_min_addr tunable.
337
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338config ARCH_SUPPORTS_MEMORY_FAILURE
339 bool
e0a94c2a 340
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341config MEMORY_FAILURE
342 depends on MMU
d949f36f 343 depends on ARCH_SUPPORTS_MEMORY_FAILURE
6a46079c 344 bool "Enable recovery from hardware memory errors"
ee6f509c 345 select MEMORY_ISOLATION
97f0b134 346 select RAS
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347 help
348 Enables code to recover from some memory failures on systems
349 with MCA recovery. This allows a system to continue running
350 even when some of its memory has uncorrected errors. This requires
351 special hardware support and typically ECC memory.
352
cae681fc 353config HWPOISON_INJECT
413f9efb 354 tristate "HWPoison pages injector"
27df5068 355 depends on MEMORY_FAILURE && DEBUG_KERNEL && PROC_FS
478c5ffc 356 select PROC_PAGE_MONITOR
cae681fc 357
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358config NOMMU_INITIAL_TRIM_EXCESS
359 int "Turn on mmap() excess space trimming before booting"
360 depends on !MMU
361 default 1
362 help
363 The NOMMU mmap() frequently needs to allocate large contiguous chunks
364 of memory on which to store mappings, but it can only ask the system
365 allocator for chunks in 2^N*PAGE_SIZE amounts - which is frequently
366 more than it requires. To deal with this, mmap() is able to trim off
367 the excess and return it to the allocator.
368
369 If trimming is enabled, the excess is trimmed off and returned to the
370 system allocator, which can cause extra fragmentation, particularly
371 if there are a lot of transient processes.
372
373 If trimming is disabled, the excess is kept, but not used, which for
374 long-term mappings means that the space is wasted.
375
376 Trimming can be dynamically controlled through a sysctl option
377 (/proc/sys/vm/nr_trim_pages) which specifies the minimum number of
378 excess pages there must be before trimming should occur, or zero if
379 no trimming is to occur.
380
381 This option specifies the initial value of this option. The default
382 of 1 says that all excess pages should be trimmed.
383
384 See Documentation/nommu-mmap.txt for more information.
bbddff05 385
4c76d9d1 386config TRANSPARENT_HUGEPAGE
13ece886 387 bool "Transparent Hugepage Support"
15626062 388 depends on HAVE_ARCH_TRANSPARENT_HUGEPAGE
5d689240 389 select COMPACTION
57578c2e 390 select RADIX_TREE_MULTIORDER
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391 help
392 Transparent Hugepages allows the kernel to use huge pages and
393 huge tlb transparently to the applications whenever possible.
394 This feature can improve computing performance to certain
395 applications by speeding up page faults during memory
396 allocation, by reducing the number of tlb misses and by speeding
397 up the pagetable walking.
398
399 If memory constrained on embedded, you may want to say N.
400
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401choice
402 prompt "Transparent Hugepage Support sysfs defaults"
403 depends on TRANSPARENT_HUGEPAGE
404 default TRANSPARENT_HUGEPAGE_ALWAYS
405 help
406 Selects the sysfs defaults for Transparent Hugepage Support.
407
408 config TRANSPARENT_HUGEPAGE_ALWAYS
409 bool "always"
410 help
411 Enabling Transparent Hugepage always, can increase the
412 memory footprint of applications without a guaranteed
413 benefit but it will work automatically for all applications.
414
415 config TRANSPARENT_HUGEPAGE_MADVISE
416 bool "madvise"
417 help
418 Enabling Transparent Hugepage madvise, will only provide a
419 performance improvement benefit to the applications using
420 madvise(MADV_HUGEPAGE) but it won't risk to increase the
421 memory footprint of applications without a guaranteed
422 benefit.
423endchoice
424
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425config ARCH_WANTS_THP_SWAP
426 def_bool n
427
428config THP_SWAP
429 def_bool y
430 depends on TRANSPARENT_HUGEPAGE && ARCH_WANTS_THP_SWAP
431 help
432 Swap transparent huge pages in one piece, without splitting.
433 XXX: For now this only does clustered swap space allocation.
434
435 For selection by architectures with reasonable THP sizes.
436
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437config TRANSPARENT_HUGE_PAGECACHE
438 def_bool y
953c66c2 439 depends on TRANSPARENT_HUGEPAGE
e496cf3d 440
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441#
442# UP and nommu archs use km based percpu allocator
443#
444config NEED_PER_CPU_KM
445 depends on !SMP
446 bool
447 default y
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448
449config CLEANCACHE
450 bool "Enable cleancache driver to cache clean pages if tmem is present"
451 default n
452 help
453 Cleancache can be thought of as a page-granularity victim cache
454 for clean pages that the kernel's pageframe replacement algorithm
455 (PFRA) would like to keep around, but can't since there isn't enough
456 memory. So when the PFRA "evicts" a page, it first attempts to use
140a1ef2 457 cleancache code to put the data contained in that page into
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458 "transcendent memory", memory that is not directly accessible or
459 addressable by the kernel and is of unknown and possibly
460 time-varying size. And when a cleancache-enabled
461 filesystem wishes to access a page in a file on disk, it first
462 checks cleancache to see if it already contains it; if it does,
463 the page is copied into the kernel and a disk access is avoided.
464 When a transcendent memory driver is available (such as zcache or
465 Xen transcendent memory), a significant I/O reduction
466 may be achieved. When none is available, all cleancache calls
467 are reduced to a single pointer-compare-against-NULL resulting
468 in a negligible performance hit.
469
470 If unsure, say Y to enable cleancache
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471
472config FRONTSWAP
473 bool "Enable frontswap to cache swap pages if tmem is present"
474 depends on SWAP
475 default n
476 help
477 Frontswap is so named because it can be thought of as the opposite
478 of a "backing" store for a swap device. The data is stored into
479 "transcendent memory", memory that is not directly accessible or
480 addressable by the kernel and is of unknown and possibly
481 time-varying size. When space in transcendent memory is available,
482 a significant swap I/O reduction may be achieved. When none is
483 available, all frontswap calls are reduced to a single pointer-
484 compare-against-NULL resulting in a negligible performance hit
485 and swap data is stored as normal on the matching swap device.
486
487 If unsure, say Y to enable frontswap.
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488
489config CMA
490 bool "Contiguous Memory Allocator"
de32a817 491 depends on HAVE_MEMBLOCK && MMU
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492 select MIGRATION
493 select MEMORY_ISOLATION
494 help
495 This enables the Contiguous Memory Allocator which allows other
496 subsystems to allocate big physically-contiguous blocks of memory.
497 CMA reserves a region of memory and allows only movable pages to
498 be allocated from it. This way, the kernel can use the memory for
499 pagecache and when a subsystem requests for contiguous area, the
500 allocated pages are migrated away to serve the contiguous request.
501
502 If unsure, say "n".
503
504config CMA_DEBUG
505 bool "CMA debug messages (DEVELOPMENT)"
506 depends on DEBUG_KERNEL && CMA
507 help
508 Turns on debug messages in CMA. This produces KERN_DEBUG
509 messages for every CMA call as well as various messages while
510 processing calls such as dma_alloc_from_contiguous().
511 This option does not affect warning and error messages.
bf550fc9 512
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513config CMA_DEBUGFS
514 bool "CMA debugfs interface"
515 depends on CMA && DEBUG_FS
516 help
517 Turns on the DebugFS interface for CMA.
518
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519config CMA_AREAS
520 int "Maximum count of the CMA areas"
521 depends on CMA
522 default 7
523 help
524 CMA allows to create CMA areas for particular purpose, mainly,
525 used as device private area. This parameter sets the maximum
526 number of CMA area in the system.
527
528 If unsure, leave the default value "7".
529
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530config MEM_SOFT_DIRTY
531 bool "Track memory changes"
532 depends on CHECKPOINT_RESTORE && HAVE_ARCH_SOFT_DIRTY && PROC_FS
533 select PROC_PAGE_MONITOR
4e2e2770 534 help
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535 This option enables memory changes tracking by introducing a
536 soft-dirty bit on pte-s. This bit it set when someone writes
537 into a page just as regular dirty bit, but unlike the latter
538 it can be cleared by hands.
539
540 See Documentation/vm/soft-dirty.txt for more details.
4e2e2770 541
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542config ZSWAP
543 bool "Compressed cache for swap pages (EXPERIMENTAL)"
544 depends on FRONTSWAP && CRYPTO=y
545 select CRYPTO_LZO
12d79d64 546 select ZPOOL
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547 default n
548 help
549 A lightweight compressed cache for swap pages. It takes
550 pages that are in the process of being swapped out and attempts to
551 compress them into a dynamically allocated RAM-based memory pool.
552 This can result in a significant I/O reduction on swap device and,
553 in the case where decompressing from RAM is faster that swap device
554 reads, can also improve workload performance.
555
556 This is marked experimental because it is a new feature (as of
557 v3.11) that interacts heavily with memory reclaim. While these
558 interactions don't cause any known issues on simple memory setups,
559 they have not be fully explored on the large set of potential
560 configurations and workloads that exist.
561
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562config ZPOOL
563 tristate "Common API for compressed memory storage"
564 default n
0f8975ec 565 help
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566 Compressed memory storage API. This allows using either zbud or
567 zsmalloc.
0f8975ec 568
af8d417a 569config ZBUD
9a001fc1 570 tristate "Low (Up to 2x) density storage for compressed pages"
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571 default n
572 help
573 A special purpose allocator for storing compressed pages.
574 It is designed to store up to two compressed pages per physical
575 page. While this design limits storage density, it has simple and
576 deterministic reclaim properties that make it preferable to a higher
577 density approach when reclaim will be used.
bcf1647d 578
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579config Z3FOLD
580 tristate "Up to 3x density storage for compressed pages"
581 depends on ZPOOL
582 default n
583 help
584 A special purpose allocator for storing compressed pages.
585 It is designed to store up to three compressed pages per physical
586 page. It is a ZBUD derivative so the simplicity and determinism are
587 still there.
588
bcf1647d 589config ZSMALLOC
d867f203 590 tristate "Memory allocator for compressed pages"
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591 depends on MMU
592 default n
593 help
594 zsmalloc is a slab-based memory allocator designed to store
595 compressed RAM pages. zsmalloc uses virtual memory mapping
596 in order to reduce fragmentation. However, this results in a
597 non-standard allocator interface where a handle, not a pointer, is
598 returned by an alloc(). This handle must be mapped in order to
599 access the allocated space.
600
601config PGTABLE_MAPPING
602 bool "Use page table mapping to access object in zsmalloc"
603 depends on ZSMALLOC
604 help
605 By default, zsmalloc uses a copy-based object mapping method to
606 access allocations that span two pages. However, if a particular
607 architecture (ex, ARM) performs VM mapping faster than copying,
608 then you should select this. This causes zsmalloc to use page table
609 mapping rather than copying for object mapping.
610
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611 You can check speed with zsmalloc benchmark:
612 https://github.com/spartacus06/zsmapbench
9e5c33d7 613
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614config ZSMALLOC_STAT
615 bool "Export zsmalloc statistics"
616 depends on ZSMALLOC
617 select DEBUG_FS
618 help
619 This option enables code in the zsmalloc to collect various
620 statistics about whats happening in zsmalloc and exports that
621 information to userspace via debugfs.
622 If unsure, say N.
623
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624config GENERIC_EARLY_IOREMAP
625 bool
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626
627config MAX_STACK_SIZE_MB
628 int "Maximum user stack size for 32-bit processes (MB)"
629 default 80
630 range 8 256 if METAG
631 range 8 2048
632 depends on STACK_GROWSUP && (!64BIT || COMPAT)
633 help
634 This is the maximum stack size in Megabytes in the VM layout of 32-bit
635 user processes when the stack grows upwards (currently only on parisc
636 and metag arch). The stack will be located at the highest memory
637 address minus the given value, unless the RLIMIT_STACK hard limit is
638 changed to a smaller value in which case that is used.
639
640 A sane initial value is 80 MB.
3a80a7fa 641
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642config HPA
643 bool "High-order Pages Allocator"
644 select CMA
645 help
646 Turns on High-order Pages Allocator based on page migration.
647
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648# For architectures that support deferred memory initialisation
649config ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
650 bool
651
652config DEFERRED_STRUCT_PAGE_INIT
1ce22103 653 bool "Defer initialisation of struct pages to kthreads"
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654 default n
655 depends on ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
11e68567 656 depends on NO_BOOTMEM && MEMORY_HOTPLUG
95794924 657 depends on !FLATMEM
fc170bda 658 depends on !NEED_PER_CPU_KM
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659 help
660 Ordinarily all struct pages are initialised during early boot in a
661 single thread. On very large machines this can take a considerable
662 amount of time. If this option is set, large machines will bring up
663 a subset of memmap at boot and then initialise the rest in parallel
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664 by starting one-off "pgdatinitX" kernel thread for each node X. This
665 has a potential performance impact on processes running early in the
666 lifetime of the system until these kthreads finish the
667 initialisation.
033fbae9 668
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669config IDLE_PAGE_TRACKING
670 bool "Enable idle page tracking"
671 depends on SYSFS && MMU
672 select PAGE_EXTENSION if !64BIT
673 help
674 This feature allows to estimate the amount of user pages that have
675 not been touched during a given period of time. This information can
676 be useful to tune memory cgroup limits and/or for job placement
677 within a compute cluster.
678
679 See Documentation/vm/idle_page_tracking.txt for more details.
680
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681# arch_add_memory() comprehends device memory
682config ARCH_HAS_ZONE_DEVICE
683 bool
684
033fbae9 685config ZONE_DEVICE
5042db43 686 bool "Device memory (pmem, HMM, etc...) hotplug support"
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687 depends on MEMORY_HOTPLUG
688 depends on MEMORY_HOTREMOVE
99490f16 689 depends on SPARSEMEM_VMEMMAP
65f7d049 690 depends on ARCH_HAS_ZONE_DEVICE
ab1b597e 691 select RADIX_TREE_MULTIORDER
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692
693 help
694 Device memory hotplug support allows for establishing pmem,
695 or other device driver discovered memory regions, in the
696 memmap. This allows pfn_to_page() lookups of otherwise
697 "device-physical" addresses which is needed for using a DAX
698 mapping in an O_DIRECT operation, among other things.
699
700 If FS_DAX is enabled, then say Y.
06a660ad 701
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702config ARCH_HAS_HMM
703 bool
704 default y
705 depends on (X86_64 || PPC64)
706 depends on ZONE_DEVICE
707 depends on MMU && 64BIT
708 depends on MEMORY_HOTPLUG
709 depends on MEMORY_HOTREMOVE
710 depends on SPARSEMEM_VMEMMAP
711
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712config MIGRATE_VMA_HELPER
713 bool
714
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715config HMM
716 bool
6b368cd4 717 select MIGRATE_VMA_HELPER
133ff0ea 718
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719config HMM_MIRROR
720 bool "HMM mirror CPU page table into a device page table"
721 depends on ARCH_HAS_HMM
722 select MMU_NOTIFIER
723 select HMM
724 help
725 Select HMM_MIRROR if you want to mirror range of the CPU page table of a
726 process into a device page table. Here, mirror means "keep synchronized".
727 Prerequisites: the device must provide the ability to write-protect its
728 page tables (at PAGE_SIZE granularity), and must be able to recover from
729 the resulting potential page faults.
730
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731config DEVICE_PRIVATE
732 bool "Unaddressable device memory (GPU memory, ...)"
733 depends on ARCH_HAS_HMM
df6ad698 734 select HMM
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735
736 help
737 Allows creation of struct pages to represent unaddressable device
738 memory; i.e., memory that is only accessible from the device (or
739 group of devices). You likely also want to select HMM_MIRROR.
740
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741config DEVICE_PUBLIC
742 bool "Addressable device memory (like GPU memory)"
743 depends on ARCH_HAS_HMM
744 select HMM
745
746 help
747 Allows creation of struct pages to represent addressable device
748 memory; i.e., memory that is accessible from both the device and
749 the CPU
750
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751config FRAME_VECTOR
752 bool
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753
754config ARCH_USES_HIGH_VMA_FLAGS
755 bool
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756config ARCH_HAS_PKEYS
757 bool
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758
759config PERCPU_STATS
760 bool "Collect percpu memory statistics"
761 default n
762 help
763 This feature collects and exposes statistics via debugfs. The
764 information includes global and per chunk statistics, which can
765 be used to help understand percpu memory usage.