1 # SPDX-License-Identifier: GPL-2.0-only 1 # SPDX-License-Identifier: GPL-2.0-only
2 2
3 menu "Memory Management options" 3 menu "Memory Management options"
4 4
5 # <<
6 # For some reason microblaze and nios2 hard co <<
7 # add proper SWAP support to them, in which ca <<
8 # <<
9 config ARCH_NO_SWAP <<
10 bool <<
11 <<
12 config ZPOOL <<
13 bool <<
14 <<
15 menuconfig SWAP <<
16 bool "Support for paging of anonymous <<
17 depends on MMU && BLOCK && !ARCH_NO_SW <<
18 default y <<
19 help <<
20 This option allows you to choose whe <<
21 for so called swap devices or swap f <<
22 used to provide more virtual memory <<
23 in your computer. If unsure say Y. <<
24 <<
25 config ZSWAP <<
26 bool "Compressed cache for swap pages" <<
27 depends on SWAP <<
28 select CRYPTO <<
29 select ZPOOL <<
30 help <<
31 A lightweight compressed cache for s <<
32 pages that are in the process of bei <<
33 compress them into a dynamically all <<
34 This can result in a significant I/O <<
35 in the case where decompressing from <<
36 reads, can also improve workload per <<
37 <<
38 config ZSWAP_DEFAULT_ON <<
39 bool "Enable the compressed cache for <<
40 depends on ZSWAP <<
41 help <<
42 If selected, the compressed cache fo <<
43 at boot, otherwise it will be disabl <<
44 <<
45 The selection made here can be overr <<
46 command line 'zswap.enabled=' option <<
47 <<
48 config ZSWAP_SHRINKER_DEFAULT_ON <<
49 bool "Shrink the zswap pool on memory <<
50 depends on ZSWAP <<
51 default n <<
52 help <<
53 If selected, the zswap shrinker will <<
54 stored in the zswap pool will become <<
55 written back to the backing swap dev <<
56 <<
57 This means that zswap writeback coul <<
58 not yet full, or the cgroup zswap li <<
59 reducing the chance that cold pages <<
60 and consume memory indefinitely. <<
61 <<
62 choice <<
63 prompt "Default compressor" <<
64 depends on ZSWAP <<
65 default ZSWAP_COMPRESSOR_DEFAULT_LZO <<
66 help <<
67 Selects the default compression algo <<
68 for swap pages. <<
69 <<
70 For an overview what kind of perform <<
71 a particular compression algorithm p <<
72 available at the following LWN page: <<
73 https://lwn.net/Articles/751795/ <<
74 <<
75 If in doubt, select 'LZO'. <<
76 <<
77 The selection made here can be overr <<
78 command line 'zswap.compressor=' opt <<
79 <<
80 config ZSWAP_COMPRESSOR_DEFAULT_DEFLATE <<
81 bool "Deflate" <<
82 select CRYPTO_DEFLATE <<
83 help <<
84 Use the Deflate algorithm as the def <<
85 <<
86 config ZSWAP_COMPRESSOR_DEFAULT_LZO <<
87 bool "LZO" <<
88 select CRYPTO_LZO <<
89 help <<
90 Use the LZO algorithm as the default <<
91 <<
92 config ZSWAP_COMPRESSOR_DEFAULT_842 <<
93 bool "842" <<
94 select CRYPTO_842 <<
95 help <<
96 Use the 842 algorithm as the default <<
97 <<
98 config ZSWAP_COMPRESSOR_DEFAULT_LZ4 <<
99 bool "LZ4" <<
100 select CRYPTO_LZ4 <<
101 help <<
102 Use the LZ4 algorithm as the default <<
103 <<
104 config ZSWAP_COMPRESSOR_DEFAULT_LZ4HC <<
105 bool "LZ4HC" <<
106 select CRYPTO_LZ4HC <<
107 help <<
108 Use the LZ4HC algorithm as the defau <<
109 <<
110 config ZSWAP_COMPRESSOR_DEFAULT_ZSTD <<
111 bool "zstd" <<
112 select CRYPTO_ZSTD <<
113 help <<
114 Use the zstd algorithm as the defaul <<
115 endchoice <<
116 <<
117 config ZSWAP_COMPRESSOR_DEFAULT <<
118 string <<
119 depends on ZSWAP <<
120 default "deflate" if ZSWAP_COMPRESSOR_D <<
121 default "lzo" if ZSWAP_COMPRESSOR_DEFAU <<
122 default "842" if ZSWAP_COMPRESSOR_DEFAU <<
123 default "lz4" if ZSWAP_COMPRESSOR_DEFAU <<
124 default "lz4hc" if ZSWAP_COMPRESSOR_DEF <<
125 default "zstd" if ZSWAP_COMPRESSOR_DEFA <<
126 default "" <<
127 <<
128 choice <<
129 prompt "Default allocator" <<
130 depends on ZSWAP <<
131 default ZSWAP_ZPOOL_DEFAULT_ZSMALLOC i <<
132 default ZSWAP_ZPOOL_DEFAULT_ZBUD <<
133 help <<
134 Selects the default allocator for th <<
135 swap pages. <<
136 The default is 'zbud' for compatibil <<
137 read the description of each of the <<
138 making a right choice. <<
139 <<
140 The selection made here can be overr <<
141 command line 'zswap.zpool=' option. <<
142 <<
143 config ZSWAP_ZPOOL_DEFAULT_ZBUD <<
144 bool "zbud" <<
145 select ZBUD <<
146 help <<
147 Use the zbud allocator as the defaul <<
148 <<
149 config ZSWAP_ZPOOL_DEFAULT_Z3FOLD_DEPRECATED <<
150 bool "z3foldi (DEPRECATED)" <<
151 select Z3FOLD_DEPRECATED <<
152 help <<
153 Use the z3fold allocator as the defa <<
154 <<
155 Deprecated and scheduled for removal <<
156 see CONFIG_Z3FOLD_DEPRECATED. <<
157 <<
158 config ZSWAP_ZPOOL_DEFAULT_ZSMALLOC <<
159 bool "zsmalloc" <<
160 select ZSMALLOC <<
161 help <<
162 Use the zsmalloc allocator as the de <<
163 endchoice <<
164 <<
165 config ZSWAP_ZPOOL_DEFAULT <<
166 string <<
167 depends on ZSWAP <<
168 default "zbud" if ZSWAP_ZPOOL_DEFAULT_Z <<
169 default "z3fold" if ZSWAP_ZPOOL_DEFAULT <<
170 default "zsmalloc" if ZSWAP_ZPOOL_DEFAU <<
171 default "" <<
172 <<
173 config ZBUD <<
174 tristate "2:1 compression allocator (z <<
175 depends on ZSWAP <<
176 help <<
177 A special purpose allocator for stor <<
178 It is designed to store up to two co <<
179 page. While this design limits stor <<
180 deterministic reclaim properties tha <<
181 density approach when reclaim will b <<
182 <<
183 config Z3FOLD_DEPRECATED <<
184 tristate "3:1 compression allocator (z <<
185 depends on ZSWAP <<
186 help <<
187 Deprecated and scheduled for removal <<
188 a good reason for using Z3FOLD over <<
189 linux-mm@kvack.org and the zswap mai <<
190 <<
191 A special purpose allocator for stor <<
192 It is designed to store up to three <<
193 page. It is a ZBUD derivative so the <<
194 still there. <<
195 <<
196 config Z3FOLD <<
197 tristate <<
198 default y if Z3FOLD_DEPRECATED=y <<
199 default m if Z3FOLD_DEPRECATED=m <<
200 depends on Z3FOLD_DEPRECATED <<
201 <<
202 config ZSMALLOC <<
203 tristate <<
204 prompt "N:1 compression allocator (zsm <<
205 depends on MMU <<
206 help <<
207 zsmalloc is a slab-based memory allo <<
208 pages of various compression levels <<
209 the highest storage density with the <<
210 <<
211 config ZSMALLOC_STAT <<
212 bool "Export zsmalloc statistics" <<
213 depends on ZSMALLOC <<
214 select DEBUG_FS <<
215 help <<
216 This option enables code in the zsma <<
217 statistics about what's happening in <<
218 information to userspace via debugfs <<
219 If unsure, say N. <<
220 <<
221 config ZSMALLOC_CHAIN_SIZE <<
222 int "Maximum number of physical pages <<
223 default 8 <<
224 range 4 16 <<
225 depends on ZSMALLOC <<
226 help <<
227 This option sets the upper limit on <<
228 that a zmalloc page (zspage) can con <<
229 chain size is calculated for each si <<
230 initialization of the pool. <<
231 <<
232 Changing this option can alter the c <<
233 such as the number of pages per zspa <<
234 per zspage. This can also result in <<
235 the pool, as zsmalloc merges size cl <<
236 characteristics. <<
237 <<
238 For more information, see zsmalloc d <<
239 <<
240 menu "Slab allocator options" <<
241 <<
242 config SLUB <<
243 def_bool y <<
244 <<
245 config SLUB_TINY <<
246 bool "Configure for minimal memory foo <<
247 depends on EXPERT <<
248 select SLAB_MERGE_DEFAULT <<
249 help <<
250 Configures the slab allocator in a <<
251 footprint, sacrificing scalability, <<
252 This is intended only for the small <<
253 SLOB allocator and is not recommend <<
254 16MB RAM. <<
255 <<
256 If unsure, say N. <<
257 <<
258 config SLAB_MERGE_DEFAULT <<
259 bool "Allow slab caches to be merged" <<
260 default y <<
261 help <<
262 For reduced kernel memory fragmentat <<
263 merged when they share the same size <<
264 This carries a risk of kernel heap o <<
265 overwrite objects from merged caches <<
266 cache layout), which makes such heap <<
267 by attackers. By keeping caches unme <<
268 can usually only damage objects in t <<
269 merging at runtime, "slab_nomerge" c <<
270 command line. <<
271 <<
272 config SLAB_FREELIST_RANDOM <<
273 bool "Randomize slab freelist" <<
274 depends on !SLUB_TINY <<
275 help <<
276 Randomizes the freelist order used o <<
277 security feature reduces the predict <<
278 allocator against heap overflows. <<
279 <<
280 config SLAB_FREELIST_HARDENED <<
281 bool "Harden slab freelist metadata" <<
282 depends on !SLUB_TINY <<
283 help <<
284 Many kernel heap attacks try to targ <<
285 other infrastructure. This options m <<
286 sacrifices to harden the kernel slab <<
287 freelist exploit methods. <<
288 <<
289 config SLAB_BUCKETS <<
290 bool "Support allocation from separate <<
291 depends on !SLUB_TINY <<
292 default SLAB_FREELIST_HARDENED <<
293 help <<
294 Kernel heap attacks frequently depen <<
295 specifically-sized allocations with <<
296 that will be allocated into the same <<
297 target object. To avoid sharing thes <<
298 provide an explicitly separated set <<
299 user-controlled allocations. This ma <<
300 memory fragmentation, though in prac <<
301 of extra pages since the bulk of use <<
302 are relatively long-lived. <<
303 <<
304 If unsure, say Y. <<
305 <<
306 config SLUB_STATS <<
307 default n <<
308 bool "Enable performance statistics" <<
309 depends on SYSFS && !SLUB_TINY <<
310 help <<
311 The statistics are useful to debug s <<
312 order find ways to optimize the allo <<
313 enabled for production use since kee <<
314 the allocator by a few percentage po <<
315 supports the determination of the mo <<
316 out which slabs are relevant to a pa <<
317 Try running: slabinfo -DA <<
318 <<
319 config SLUB_CPU_PARTIAL <<
320 default y <<
321 depends on SMP && !SLUB_TINY <<
322 bool "Enable per cpu partial caches" <<
323 help <<
324 Per cpu partial caches accelerate ob <<
325 that is local to a processor at the <<
326 in the latency of the free. On overf <<
327 which requires the taking of locks t <<
328 Typically one would choose no for a <<
329 <<
330 config RANDOM_KMALLOC_CACHES <<
331 default n <<
332 depends on !SLUB_TINY <<
333 bool "Randomize slab caches for normal <<
334 help <<
335 A hardening feature that creates mul <<
336 normal kmalloc allocation and makes <<
337 on code address, which makes the att <<
338 vulnerable memory objects on the hea <<
339 memory vulnerabilities. <<
340 <<
341 Currently the number of copies is se <<
342 that effectively diverges the memory <<
343 subsystems or modules into different <<
344 limited degree of memory and CPU ove <<
345 system workload. <<
346 <<
347 endmenu # Slab allocator options <<
348 <<
349 config SHUFFLE_PAGE_ALLOCATOR <<
350 bool "Page allocator randomization" <<
351 default SLAB_FREELIST_RANDOM && ACPI_N <<
352 help <<
353 Randomization of the page allocator <<
354 utilization of a direct-mapped memor <<
355 5.2.27 Heterogeneous Memory Attribut <<
356 6.2a specification for an example of <<
357 the presence of a memory-side-cache. <<
358 security benefits as it reduces the <<
359 allocations to compliment SLAB_FREEL <<
360 default granularity of shuffling on <<
361 order of pages is selected based on <<
362 on x86. <<
363 <<
364 While the randomization improves cac <<
365 negatively impact workloads on platf <<
366 this reason, by default, the randomi <<
367 if SHUFFLE_PAGE_ALLOCATOR=y. The ran <<
368 with the 'page_alloc.shuffle' kernel <<
369 <<
370 Say Y if unsure. <<
371 <<
372 config COMPAT_BRK <<
373 bool "Disable heap randomization" <<
374 default y <<
375 help <<
376 Randomizing heap placement makes hea <<
377 also breaks ancient binaries (includ <<
378 This option changes the bootup defau <<
379 disabled, and can be overridden at r <<
380 /proc/sys/kernel/randomize_va_space <<
381 <<
382 On non-ancient distros (post-2000 on <<
383 <<
384 config MMAP_ALLOW_UNINITIALIZED <<
385 bool "Allow mmapped anonymous memory t <<
386 depends on EXPERT && !MMU <<
387 default n <<
388 help <<
389 Normally, and according to the Linux <<
390 from mmap() has its contents cleared <<
391 userspace. Enabling this config opt <<
392 mmap() skip that if it is given an M <<
393 providing a huge performance boost. <<
394 then the flag will be ignored. <<
395 <<
396 This is taken advantage of by uClibc <<
397 ELF-FDPIC binfmt's brk and stack all <<
398 <<
399 Because of the obvious security issu <<
400 enabled on embedded devices where yo <<
401 userspace. Since that isn't general <<
402 it is normally safe to say Y here. <<
403 <<
404 See Documentation/admin-guide/mm/nom <<
405 <<
406 config SELECT_MEMORY_MODEL 5 config SELECT_MEMORY_MODEL
407 def_bool y 6 def_bool y
408 depends on ARCH_SELECT_MEMORY_MODEL 7 depends on ARCH_SELECT_MEMORY_MODEL
409 8
410 choice 9 choice
411 prompt "Memory model" 10 prompt "Memory model"
412 depends on SELECT_MEMORY_MODEL 11 depends on SELECT_MEMORY_MODEL
413 default SPARSEMEM_MANUAL if ARCH_SPARS 12 default SPARSEMEM_MANUAL if ARCH_SPARSEMEM_DEFAULT
414 default FLATMEM_MANUAL 13 default FLATMEM_MANUAL
415 help 14 help
416 This option allows you to change som 15 This option allows you to change some of the ways that
417 Linux manages its memory internally. 16 Linux manages its memory internally. Most users will
418 only have one option here selected b 17 only have one option here selected by the architecture
419 configuration. This is normal. 18 configuration. This is normal.
420 19
421 config FLATMEM_MANUAL 20 config FLATMEM_MANUAL
422 bool "Flat Memory" 21 bool "Flat Memory"
423 depends on !ARCH_SPARSEMEM_ENABLE || A 22 depends on !ARCH_SPARSEMEM_ENABLE || ARCH_FLATMEM_ENABLE
424 help 23 help
425 This option is best suited for non-N 24 This option is best suited for non-NUMA systems with
426 flat address space. The FLATMEM is t 25 flat address space. The FLATMEM is the most efficient
427 system in terms of performance and r 26 system in terms of performance and resource consumption
428 and it is the best option for smalle 27 and it is the best option for smaller systems.
429 28
430 For systems that have holes in their 29 For systems that have holes in their physical address
431 spaces and for features like NUMA an 30 spaces and for features like NUMA and memory hotplug,
432 choose "Sparse Memory". 31 choose "Sparse Memory".
433 32
434 If unsure, choose this option (Flat 33 If unsure, choose this option (Flat Memory) over any other.
435 34
436 config SPARSEMEM_MANUAL 35 config SPARSEMEM_MANUAL
437 bool "Sparse Memory" 36 bool "Sparse Memory"
438 depends on ARCH_SPARSEMEM_ENABLE 37 depends on ARCH_SPARSEMEM_ENABLE
439 help 38 help
440 This will be the only option for som 39 This will be the only option for some systems, including
441 memory hot-plug systems. This is no 40 memory hot-plug systems. This is normal.
442 41
443 This option provides efficient suppo 42 This option provides efficient support for systems with
444 holes is their physical address spac 43 holes is their physical address space and allows memory
445 hot-plug and hot-remove. 44 hot-plug and hot-remove.
446 45
447 If unsure, choose "Flat Memory" over 46 If unsure, choose "Flat Memory" over this option.
448 47
449 endchoice 48 endchoice
450 49
451 config SPARSEMEM 50 config SPARSEMEM
452 def_bool y 51 def_bool y
453 depends on (!SELECT_MEMORY_MODEL && AR 52 depends on (!SELECT_MEMORY_MODEL && ARCH_SPARSEMEM_ENABLE) || SPARSEMEM_MANUAL
454 53
455 config FLATMEM 54 config FLATMEM
456 def_bool y 55 def_bool y
457 depends on !SPARSEMEM || FLATMEM_MANUA 56 depends on !SPARSEMEM || FLATMEM_MANUAL
458 57
459 # 58 #
460 # SPARSEMEM_EXTREME (which is the default) doe 59 # SPARSEMEM_EXTREME (which is the default) does some bootmem
461 # allocations when sparse_init() is called. I 60 # allocations when sparse_init() is called. If this cannot
462 # be done on your architecture, select this op 61 # be done on your architecture, select this option. However,
463 # statically allocating the mem_section[] arra 62 # statically allocating the mem_section[] array can potentially
464 # consume vast quantities of .bss, so be caref 63 # consume vast quantities of .bss, so be careful.
465 # 64 #
466 # This option will also potentially produce sm 65 # This option will also potentially produce smaller runtime code
467 # with gcc 3.4 and later. 66 # with gcc 3.4 and later.
468 # 67 #
469 config SPARSEMEM_STATIC 68 config SPARSEMEM_STATIC
470 bool 69 bool
471 70
472 # 71 #
473 # Architecture platforms which require a two l 72 # Architecture platforms which require a two level mem_section in SPARSEMEM
474 # must select this option. This is usually for 73 # must select this option. This is usually for architecture platforms with
475 # an extremely sparse physical address space. 74 # an extremely sparse physical address space.
476 # 75 #
477 config SPARSEMEM_EXTREME 76 config SPARSEMEM_EXTREME
478 def_bool y 77 def_bool y
479 depends on SPARSEMEM && !SPARSEMEM_STA 78 depends on SPARSEMEM && !SPARSEMEM_STATIC
480 79
481 config SPARSEMEM_VMEMMAP_ENABLE 80 config SPARSEMEM_VMEMMAP_ENABLE
482 bool 81 bool
483 82
484 config SPARSEMEM_VMEMMAP 83 config SPARSEMEM_VMEMMAP
485 bool "Sparse Memory virtual memmap" 84 bool "Sparse Memory virtual memmap"
486 depends on SPARSEMEM && SPARSEMEM_VMEM 85 depends on SPARSEMEM && SPARSEMEM_VMEMMAP_ENABLE
487 default y 86 default y
488 help 87 help
489 SPARSEMEM_VMEMMAP uses a virtually m 88 SPARSEMEM_VMEMMAP uses a virtually mapped memmap to optimise
490 pfn_to_page and page_to_pfn operatio 89 pfn_to_page and page_to_pfn operations. This is the most
491 efficient option when sufficient ker 90 efficient option when sufficient kernel resources are available.
492 # <<
493 # Select this config option from the architect <<
494 # to enable the feature of HugeTLB/dev_dax vme <<
495 # <<
496 config ARCH_WANT_OPTIMIZE_DAX_VMEMMAP <<
497 bool <<
498 <<
499 config ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP <<
500 bool <<
501 91
502 config HAVE_MEMBLOCK_PHYS_MAP 92 config HAVE_MEMBLOCK_PHYS_MAP
503 bool 93 bool
504 94
505 config HAVE_GUP_FAST !! 95 config HAVE_FAST_GUP
506 depends on MMU 96 depends on MMU
507 bool 97 bool
508 98
509 # Don't discard allocated memory used to track 99 # Don't discard allocated memory used to track "memory" and "reserved" memblocks
510 # after early boot, so it can still be used to 100 # after early boot, so it can still be used to test for validity of memory.
511 # Also, memblocks are updated with memory hot( 101 # Also, memblocks are updated with memory hot(un)plug.
512 config ARCH_KEEP_MEMBLOCK 102 config ARCH_KEEP_MEMBLOCK
513 bool 103 bool
514 104
515 # Keep arch NUMA mapping infrastructure post-i 105 # Keep arch NUMA mapping infrastructure post-init.
516 config NUMA_KEEP_MEMINFO 106 config NUMA_KEEP_MEMINFO
517 bool 107 bool
518 108
519 config MEMORY_ISOLATION 109 config MEMORY_ISOLATION
520 bool 110 bool
521 111
522 # IORESOURCE_SYSTEM_RAM regions in the kernel 112 # IORESOURCE_SYSTEM_RAM regions in the kernel resource tree that are marked
523 # IORESOURCE_EXCLUSIVE cannot be mapped to use 113 # IORESOURCE_EXCLUSIVE cannot be mapped to user space, for example, via
524 # /dev/mem. 114 # /dev/mem.
525 config EXCLUSIVE_SYSTEM_RAM 115 config EXCLUSIVE_SYSTEM_RAM
526 def_bool y 116 def_bool y
527 depends on !DEVMEM || STRICT_DEVMEM 117 depends on !DEVMEM || STRICT_DEVMEM
528 118
529 # 119 #
530 # Only be set on architectures that have compl 120 # Only be set on architectures that have completely implemented memory hotplug
531 # feature. If you are not sure, don't touch it 121 # feature. If you are not sure, don't touch it.
532 # 122 #
533 config HAVE_BOOTMEM_INFO_NODE 123 config HAVE_BOOTMEM_INFO_NODE
534 def_bool n 124 def_bool n
535 125
536 config ARCH_ENABLE_MEMORY_HOTPLUG 126 config ARCH_ENABLE_MEMORY_HOTPLUG
537 bool 127 bool
538 128
539 config ARCH_ENABLE_MEMORY_HOTREMOVE <<
540 bool <<
541 <<
542 # eventually, we can have this option just 'se 129 # eventually, we can have this option just 'select SPARSEMEM'
543 menuconfig MEMORY_HOTPLUG !! 130 config MEMORY_HOTPLUG
544 bool "Memory hotplug" !! 131 bool "Allow for memory hot-add"
545 select MEMORY_ISOLATION 132 select MEMORY_ISOLATION
546 depends on SPARSEMEM 133 depends on SPARSEMEM
547 depends on ARCH_ENABLE_MEMORY_HOTPLUG 134 depends on ARCH_ENABLE_MEMORY_HOTPLUG
548 depends on 64BIT 135 depends on 64BIT
549 select NUMA_KEEP_MEMINFO if NUMA 136 select NUMA_KEEP_MEMINFO if NUMA
550 137
551 if MEMORY_HOTPLUG <<
552 <<
553 config MEMORY_HOTPLUG_DEFAULT_ONLINE 138 config MEMORY_HOTPLUG_DEFAULT_ONLINE
554 bool "Online the newly added memory bl 139 bool "Online the newly added memory blocks by default"
555 depends on MEMORY_HOTPLUG 140 depends on MEMORY_HOTPLUG
556 help 141 help
557 This option sets the default policy 142 This option sets the default policy setting for memory hotplug
558 onlining policy (/sys/devices/system 143 onlining policy (/sys/devices/system/memory/auto_online_blocks) which
559 determines what happens to newly add 144 determines what happens to newly added memory regions. Policy setting
560 can always be changed at runtime. 145 can always be changed at runtime.
561 See Documentation/admin-guide/mm/mem 146 See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
562 147
563 Say Y here if you want all hot-plugg 148 Say Y here if you want all hot-plugged memory blocks to appear in
564 'online' state by default. 149 'online' state by default.
565 Say N here if you want the default p 150 Say N here if you want the default policy to keep all hot-plugged
566 memory blocks in 'offline' state. 151 memory blocks in 'offline' state.
567 152
>> 153 config ARCH_ENABLE_MEMORY_HOTREMOVE
>> 154 bool
>> 155
568 config MEMORY_HOTREMOVE 156 config MEMORY_HOTREMOVE
569 bool "Allow for memory hot remove" 157 bool "Allow for memory hot remove"
570 select HAVE_BOOTMEM_INFO_NODE if (X86_ 158 select HAVE_BOOTMEM_INFO_NODE if (X86_64 || PPC64)
571 depends on MEMORY_HOTPLUG && ARCH_ENAB 159 depends on MEMORY_HOTPLUG && ARCH_ENABLE_MEMORY_HOTREMOVE
572 depends on MIGRATION 160 depends on MIGRATION
573 161
574 config MHP_MEMMAP_ON_MEMORY 162 config MHP_MEMMAP_ON_MEMORY
575 def_bool y 163 def_bool y
576 depends on MEMORY_HOTPLUG && SPARSEMEM 164 depends on MEMORY_HOTPLUG && SPARSEMEM_VMEMMAP
577 depends on ARCH_MHP_MEMMAP_ON_MEMORY_E 165 depends on ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
578 166
579 endif # MEMORY_HOTPLUG <<
580 <<
581 config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE <<
582 bool <<
583 <<
584 # Heavily threaded applications may benefit fr 167 # Heavily threaded applications may benefit from splitting the mm-wide
585 # page_table_lock, so that faults on different 168 # page_table_lock, so that faults on different parts of the user address
586 # space can be handled with less contention: s 169 # space can be handled with less contention: split it at this NR_CPUS.
587 # Default to 4 for wider testing, though 8 mig 170 # Default to 4 for wider testing, though 8 might be more appropriate.
588 # ARM's adjust_pte (unused if VIPT) depends on 171 # ARM's adjust_pte (unused if VIPT) depends on mm-wide page_table_lock.
589 # PA-RISC 7xxx's spinlock_t would enlarge stru 172 # PA-RISC 7xxx's spinlock_t would enlarge struct page from 32 to 44 bytes.
590 # SPARC32 allocates multiple pte tables within 173 # SPARC32 allocates multiple pte tables within a single page, and therefore
591 # a per-page lock leads to problems when multi 174 # a per-page lock leads to problems when multiple tables need to be locked
592 # at the same time (e.g. copy_page_range()). 175 # at the same time (e.g. copy_page_range()).
593 # DEBUG_SPINLOCK and DEBUG_LOCK_ALLOC spinlock 176 # DEBUG_SPINLOCK and DEBUG_LOCK_ALLOC spinlock_t also enlarge struct page.
594 # 177 #
595 config SPLIT_PTE_PTLOCKS !! 178 config SPLIT_PTLOCK_CPUS
596 def_bool y !! 179 int
597 depends on MMU !! 180 default "999999" if !MMU
598 depends on SMP !! 181 default "999999" if ARM && !CPU_CACHE_VIPT
599 depends on NR_CPUS >= 4 !! 182 default "999999" if PARISC && !PA20
600 depends on !ARM || CPU_CACHE_VIPT !! 183 default "999999" if SPARC32
601 depends on !PARISC || PA20 !! 184 default "4"
602 depends on !SPARC32 <<
603 185
604 config ARCH_ENABLE_SPLIT_PMD_PTLOCK 186 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
605 bool 187 bool
606 188
607 config SPLIT_PMD_PTLOCKS <<
608 def_bool y <<
609 depends on SPLIT_PTE_PTLOCKS && ARCH_E <<
610 <<
611 # 189 #
612 # support for memory balloon 190 # support for memory balloon
613 config MEMORY_BALLOON 191 config MEMORY_BALLOON
614 bool 192 bool
615 193
616 # 194 #
617 # support for memory balloon compaction 195 # support for memory balloon compaction
618 config BALLOON_COMPACTION 196 config BALLOON_COMPACTION
619 bool "Allow for balloon memory compact 197 bool "Allow for balloon memory compaction/migration"
620 default y !! 198 def_bool y
621 depends on COMPACTION && MEMORY_BALLOO 199 depends on COMPACTION && MEMORY_BALLOON
622 help 200 help
623 Memory fragmentation introduced by b 201 Memory fragmentation introduced by ballooning might reduce
624 significantly the number of 2MB cont 202 significantly the number of 2MB contiguous memory blocks that can be
625 used within a guest, thus imposing p 203 used within a guest, thus imposing performance penalties associated
626 with the reduced number of transpare 204 with the reduced number of transparent huge pages that could be used
627 by the guest workload. Allowing the 205 by the guest workload. Allowing the compaction & migration for memory
628 pages enlisted as being part of memo 206 pages enlisted as being part of memory balloon devices avoids the
629 scenario aforementioned and helps im 207 scenario aforementioned and helps improving memory defragmentation.
630 208
631 # 209 #
632 # support for memory compaction 210 # support for memory compaction
633 config COMPACTION 211 config COMPACTION
634 bool "Allow for memory compaction" 212 bool "Allow for memory compaction"
635 default y !! 213 def_bool y
636 select MIGRATION 214 select MIGRATION
637 depends on MMU 215 depends on MMU
638 help 216 help
639 Compaction is the only memory manage 217 Compaction is the only memory management component to form
640 high order (larger physically contig 218 high order (larger physically contiguous) memory blocks
641 reliably. The page allocator relies 219 reliably. The page allocator relies on compaction heavily and
642 the lack of the feature can lead to 220 the lack of the feature can lead to unexpected OOM killer
643 invocations for high order memory re 221 invocations for high order memory requests. You shouldn't
644 disable this option unless there rea 222 disable this option unless there really is a strong reason for
645 it and then we would be really inter 223 it and then we would be really interested to hear about that at
646 linux-mm@kvack.org. 224 linux-mm@kvack.org.
647 225
648 config COMPACT_UNEVICTABLE_DEFAULT <<
649 int <<
650 depends on COMPACTION <<
651 default 0 if PREEMPT_RT <<
652 default 1 <<
653 <<
654 # 226 #
655 # support for free page reporting 227 # support for free page reporting
656 config PAGE_REPORTING 228 config PAGE_REPORTING
657 bool "Free page reporting" 229 bool "Free page reporting"
>> 230 def_bool n
658 help 231 help
659 Free page reporting allows for the i 232 Free page reporting allows for the incremental acquisition of
660 free pages from the buddy allocator 233 free pages from the buddy allocator for the purpose of reporting
661 those pages to another entity, such 234 those pages to another entity, such as a hypervisor, so that the
662 memory can be freed within the host 235 memory can be freed within the host for other uses.
663 236
664 # 237 #
665 # support for page migration 238 # support for page migration
666 # 239 #
667 config MIGRATION 240 config MIGRATION
668 bool "Page migration" 241 bool "Page migration"
669 default y !! 242 def_bool y
670 depends on (NUMA || ARCH_ENABLE_MEMORY 243 depends on (NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE || COMPACTION || CMA) && MMU
671 help 244 help
672 Allows the migration of the physical 245 Allows the migration of the physical location of pages of processes
673 while the virtual addresses are not 246 while the virtual addresses are not changed. This is useful in
674 two situations. The first is on NUMA 247 two situations. The first is on NUMA systems to put pages nearer
675 to the processors accessing. The sec 248 to the processors accessing. The second is when allocating huge
676 pages as migration can relocate page 249 pages as migration can relocate pages to satisfy a huge page
677 allocation instead of reclaiming. 250 allocation instead of reclaiming.
678 251
679 config DEVICE_MIGRATION 252 config DEVICE_MIGRATION
680 def_bool MIGRATION && ZONE_DEVICE 253 def_bool MIGRATION && ZONE_DEVICE
681 254
682 config ARCH_ENABLE_HUGEPAGE_MIGRATION 255 config ARCH_ENABLE_HUGEPAGE_MIGRATION
683 bool 256 bool
684 257
685 config ARCH_ENABLE_THP_MIGRATION 258 config ARCH_ENABLE_THP_MIGRATION
686 bool 259 bool
687 260
688 config HUGETLB_PAGE_SIZE_VARIABLE 261 config HUGETLB_PAGE_SIZE_VARIABLE
689 def_bool n 262 def_bool n
690 help 263 help
691 Allows the pageblock_order value to 264 Allows the pageblock_order value to be dynamic instead of just standard
692 HUGETLB_PAGE_ORDER when there are mu 265 HUGETLB_PAGE_ORDER when there are multiple HugeTLB page sizes available
693 on a platform. 266 on a platform.
694 267
695 Note that the pageblock_order cannot !! 268 Note that the pageblock_order cannot exceed MAX_ORDER - 1 and will be
696 clamped down to MAX_PAGE_ORDER. !! 269 clamped down to MAX_ORDER - 1.
697 270
698 config CONTIG_ALLOC 271 config CONTIG_ALLOC
699 def_bool (MEMORY_ISOLATION && COMPACTI 272 def_bool (MEMORY_ISOLATION && COMPACTION) || CMA
700 273
701 config PCP_BATCH_SCALE_MAX <<
702 int "Maximum scale factor of PCP (Per- <<
703 default 5 <<
704 range 0 6 <<
705 help <<
706 In page allocator, PCP (Per-CPU page <<
707 batches. The batch number is scaled <<
708 allocation/free throughput. But too <<
709 latency. This option sets the upper <<
710 the maximum latency. <<
711 <<
712 config PHYS_ADDR_T_64BIT 274 config PHYS_ADDR_T_64BIT
713 def_bool 64BIT 275 def_bool 64BIT
714 276
715 config BOUNCE 277 config BOUNCE
716 bool "Enable bounce buffers" 278 bool "Enable bounce buffers"
717 default y 279 default y
718 depends on BLOCK && MMU && HIGHMEM 280 depends on BLOCK && MMU && HIGHMEM
719 help 281 help
720 Enable bounce buffers for devices th 282 Enable bounce buffers for devices that cannot access the full range of
721 memory available to the CPU. Enabled 283 memory available to the CPU. Enabled by default when HIGHMEM is
722 selected, but you may say n to overr 284 selected, but you may say n to override this.
723 285
>> 286 config VIRT_TO_BUS
>> 287 bool
>> 288 help
>> 289 An architecture should select this if it implements the
>> 290 deprecated interface virt_to_bus(). All new architectures
>> 291 should probably not select this.
>> 292
>> 293
724 config MMU_NOTIFIER 294 config MMU_NOTIFIER
725 bool 295 bool
>> 296 select SRCU
726 select INTERVAL_TREE 297 select INTERVAL_TREE
727 298
728 config KSM 299 config KSM
729 bool "Enable KSM for page merging" 300 bool "Enable KSM for page merging"
730 depends on MMU 301 depends on MMU
731 select XXHASH 302 select XXHASH
732 help 303 help
733 Enable Kernel Samepage Merging: KSM 304 Enable Kernel Samepage Merging: KSM periodically scans those areas
734 of an application's address space th 305 of an application's address space that an app has advised may be
735 mergeable. When it finds pages of i 306 mergeable. When it finds pages of identical content, it replaces
736 the many instances by a single page 307 the many instances by a single page with that content, so
737 saving memory until one or another a 308 saving memory until one or another app needs to modify the content.
738 Recommended for use with KVM, or wit 309 Recommended for use with KVM, or with other duplicative applications.
739 See Documentation/mm/ksm.rst for mor !! 310 See Documentation/vm/ksm.rst for more information: KSM is inactive
740 until a program has madvised that an 311 until a program has madvised that an area is MADV_MERGEABLE, and
741 root has set /sys/kernel/mm/ksm/run 312 root has set /sys/kernel/mm/ksm/run to 1 (if CONFIG_SYSFS is set).
742 313
743 config DEFAULT_MMAP_MIN_ADDR 314 config DEFAULT_MMAP_MIN_ADDR
744 int "Low address space to protect from 315 int "Low address space to protect from user allocation"
745 depends on MMU 316 depends on MMU
746 default 4096 317 default 4096
747 help 318 help
748 This is the portion of low virtual m 319 This is the portion of low virtual memory which should be protected
749 from userspace allocation. Keeping 320 from userspace allocation. Keeping a user from writing to low pages
750 can help reduce the impact of kernel 321 can help reduce the impact of kernel NULL pointer bugs.
751 322
752 For most arm64, ppc64 and x86 users !! 323 For most ia64, ppc64 and x86 users with lots of address space
753 a value of 65536 is reasonable and s 324 a value of 65536 is reasonable and should cause no problems.
754 On arm and other archs it should not 325 On arm and other archs it should not be higher than 32768.
755 Programs which use vm86 functionalit 326 Programs which use vm86 functionality or have some need to map
756 this low address space will need CAP 327 this low address space will need CAP_SYS_RAWIO or disable this
757 protection by setting the value to 0 328 protection by setting the value to 0.
758 329
759 This value can be changed after boot 330 This value can be changed after boot using the
760 /proc/sys/vm/mmap_min_addr tunable. 331 /proc/sys/vm/mmap_min_addr tunable.
761 332
762 config ARCH_SUPPORTS_MEMORY_FAILURE 333 config ARCH_SUPPORTS_MEMORY_FAILURE
763 bool 334 bool
764 335
765 config MEMORY_FAILURE 336 config MEMORY_FAILURE
766 depends on MMU 337 depends on MMU
767 depends on ARCH_SUPPORTS_MEMORY_FAILUR 338 depends on ARCH_SUPPORTS_MEMORY_FAILURE
768 bool "Enable recovery from hardware me 339 bool "Enable recovery from hardware memory errors"
769 select MEMORY_ISOLATION 340 select MEMORY_ISOLATION
770 select RAS 341 select RAS
771 help 342 help
772 Enables code to recover from some me 343 Enables code to recover from some memory failures on systems
773 with MCA recovery. This allows a sys 344 with MCA recovery. This allows a system to continue running
774 even when some of its memory has unc 345 even when some of its memory has uncorrected errors. This requires
775 special hardware support and typical 346 special hardware support and typically ECC memory.
776 347
777 config HWPOISON_INJECT 348 config HWPOISON_INJECT
778 tristate "HWPoison pages injector" 349 tristate "HWPoison pages injector"
779 depends on MEMORY_FAILURE && DEBUG_KER 350 depends on MEMORY_FAILURE && DEBUG_KERNEL && PROC_FS
780 select PROC_PAGE_MONITOR 351 select PROC_PAGE_MONITOR
781 352
782 config NOMMU_INITIAL_TRIM_EXCESS 353 config NOMMU_INITIAL_TRIM_EXCESS
783 int "Turn on mmap() excess space trimm 354 int "Turn on mmap() excess space trimming before booting"
784 depends on !MMU 355 depends on !MMU
785 default 1 356 default 1
786 help 357 help
787 The NOMMU mmap() frequently needs to 358 The NOMMU mmap() frequently needs to allocate large contiguous chunks
788 of memory on which to store mappings 359 of memory on which to store mappings, but it can only ask the system
789 allocator for chunks in 2^N*PAGE_SIZ 360 allocator for chunks in 2^N*PAGE_SIZE amounts - which is frequently
790 more than it requires. To deal with 361 more than it requires. To deal with this, mmap() is able to trim off
791 the excess and return it to the allo 362 the excess and return it to the allocator.
792 363
793 If trimming is enabled, the excess i 364 If trimming is enabled, the excess is trimmed off and returned to the
794 system allocator, which can cause ex 365 system allocator, which can cause extra fragmentation, particularly
795 if there are a lot of transient proc 366 if there are a lot of transient processes.
796 367
797 If trimming is disabled, the excess 368 If trimming is disabled, the excess is kept, but not used, which for
798 long-term mappings means that the sp 369 long-term mappings means that the space is wasted.
799 370
800 Trimming can be dynamically controll 371 Trimming can be dynamically controlled through a sysctl option
801 (/proc/sys/vm/nr_trim_pages) which s 372 (/proc/sys/vm/nr_trim_pages) which specifies the minimum number of
802 excess pages there must be before tr 373 excess pages there must be before trimming should occur, or zero if
803 no trimming is to occur. 374 no trimming is to occur.
804 375
805 This option specifies the initial va 376 This option specifies the initial value of this option. The default
806 of 1 says that all excess pages shou 377 of 1 says that all excess pages should be trimmed.
807 378
808 See Documentation/admin-guide/mm/nom 379 See Documentation/admin-guide/mm/nommu-mmap.rst for more information.
809 380
810 config ARCH_WANT_GENERAL_HUGETLB !! 381 config TRANSPARENT_HUGEPAGE
811 bool <<
812 <<
813 config ARCH_WANTS_THP_SWAP <<
814 def_bool n <<
815 <<
816 menuconfig TRANSPARENT_HUGEPAGE <<
817 bool "Transparent Hugepage Support" 382 bool "Transparent Hugepage Support"
818 depends on HAVE_ARCH_TRANSPARENT_HUGEP 383 depends on HAVE_ARCH_TRANSPARENT_HUGEPAGE && !PREEMPT_RT
819 select COMPACTION 384 select COMPACTION
820 select XARRAY_MULTI 385 select XARRAY_MULTI
821 help 386 help
822 Transparent Hugepages allows the ker 387 Transparent Hugepages allows the kernel to use huge pages and
823 huge tlb transparently to the applic 388 huge tlb transparently to the applications whenever possible.
824 This feature can improve computing p 389 This feature can improve computing performance to certain
825 applications by speeding up page fau 390 applications by speeding up page faults during memory
826 allocation, by reducing the number o 391 allocation, by reducing the number of tlb misses and by speeding
827 up the pagetable walking. 392 up the pagetable walking.
828 393
829 If memory constrained on embedded, y 394 If memory constrained on embedded, you may want to say N.
830 395
831 if TRANSPARENT_HUGEPAGE <<
832 <<
833 choice 396 choice
834 prompt "Transparent Hugepage Support s 397 prompt "Transparent Hugepage Support sysfs defaults"
835 depends on TRANSPARENT_HUGEPAGE 398 depends on TRANSPARENT_HUGEPAGE
836 default TRANSPARENT_HUGEPAGE_ALWAYS 399 default TRANSPARENT_HUGEPAGE_ALWAYS
837 help 400 help
838 Selects the sysfs defaults for Trans 401 Selects the sysfs defaults for Transparent Hugepage Support.
839 402
840 config TRANSPARENT_HUGEPAGE_ALWAYS 403 config TRANSPARENT_HUGEPAGE_ALWAYS
841 bool "always" 404 bool "always"
842 help 405 help
843 Enabling Transparent Hugepage always 406 Enabling Transparent Hugepage always, can increase the
844 memory footprint of applications wit 407 memory footprint of applications without a guaranteed
845 benefit but it will work automatical 408 benefit but it will work automatically for all applications.
846 409
847 config TRANSPARENT_HUGEPAGE_MADVISE 410 config TRANSPARENT_HUGEPAGE_MADVISE
848 bool "madvise" 411 bool "madvise"
849 help 412 help
850 Enabling Transparent Hugepage madvis 413 Enabling Transparent Hugepage madvise, will only provide a
851 performance improvement benefit to t 414 performance improvement benefit to the applications using
852 madvise(MADV_HUGEPAGE) but it won't 415 madvise(MADV_HUGEPAGE) but it won't risk to increase the
853 memory footprint of applications wit 416 memory footprint of applications without a guaranteed
854 benefit. 417 benefit.
855 <<
856 config TRANSPARENT_HUGEPAGE_NEVER <<
857 bool "never" <<
858 help <<
859 Disable Transparent Hugepage by defa <<
860 enabled at runtime via sysfs. <<
861 endchoice 418 endchoice
862 419
>> 420 config ARCH_WANT_GENERAL_HUGETLB
>> 421 bool
>> 422
>> 423 config ARCH_WANTS_THP_SWAP
>> 424 def_bool n
>> 425
863 config THP_SWAP 426 config THP_SWAP
864 def_bool y 427 def_bool y
865 depends on TRANSPARENT_HUGEPAGE && ARC !! 428 depends on TRANSPARENT_HUGEPAGE && ARCH_WANTS_THP_SWAP && SWAP
866 help 429 help
867 Swap transparent huge pages in one p 430 Swap transparent huge pages in one piece, without splitting.
868 XXX: For now, swap cluster backing t 431 XXX: For now, swap cluster backing transparent huge page
869 will be split after swapout. 432 will be split after swapout.
870 433
871 For selection by architectures with 434 For selection by architectures with reasonable THP sizes.
872 435
873 config READ_ONLY_THP_FOR_FS <<
874 bool "Read-only THP for filesystems (E <<
875 depends on TRANSPARENT_HUGEPAGE && SHM <<
876 <<
877 help <<
878 Allow khugepaged to put read-only fi <<
879 <<
880 This is marked experimental because <<
881 support of file THPs will be develop <<
882 cycles. <<
883 <<
884 endif # TRANSPARENT_HUGEPAGE <<
885 <<
886 # <<
887 # The architecture supports pgtable leaves tha <<
888 # <<
889 config PGTABLE_HAS_HUGE_LEAVES <<
890 def_bool TRANSPARENT_HUGEPAGE || HUGET <<
891 <<
892 # TODO: Allow to be enabled without THP <<
893 config ARCH_SUPPORTS_HUGE_PFNMAP <<
894 def_bool n <<
895 depends on TRANSPARENT_HUGEPAGE <<
896 <<
897 config ARCH_SUPPORTS_PMD_PFNMAP <<
898 def_bool y <<
899 depends on ARCH_SUPPORTS_HUGE_PFNMAP & <<
900 <<
901 config ARCH_SUPPORTS_PUD_PFNMAP <<
902 def_bool y <<
903 depends on ARCH_SUPPORTS_HUGE_PFNMAP & <<
904 <<
905 # 436 #
906 # UP and nommu archs use km based percpu alloc 437 # UP and nommu archs use km based percpu allocator
907 # 438 #
908 config NEED_PER_CPU_KM 439 config NEED_PER_CPU_KM
909 depends on !SMP || !MMU 440 depends on !SMP || !MMU
910 bool 441 bool
911 default y 442 default y
912 443
913 config NEED_PER_CPU_EMBED_FIRST_CHUNK 444 config NEED_PER_CPU_EMBED_FIRST_CHUNK
914 bool 445 bool
915 446
916 config NEED_PER_CPU_PAGE_FIRST_CHUNK 447 config NEED_PER_CPU_PAGE_FIRST_CHUNK
917 bool 448 bool
918 449
919 config USE_PERCPU_NUMA_NODE_ID 450 config USE_PERCPU_NUMA_NODE_ID
920 bool 451 bool
921 452
922 config HAVE_SETUP_PER_CPU_AREA 453 config HAVE_SETUP_PER_CPU_AREA
923 bool 454 bool
924 455
>> 456 config FRONTSWAP
>> 457 bool
>> 458
925 config CMA 459 config CMA
926 bool "Contiguous Memory Allocator" 460 bool "Contiguous Memory Allocator"
927 depends on MMU 461 depends on MMU
928 select MIGRATION 462 select MIGRATION
929 select MEMORY_ISOLATION 463 select MEMORY_ISOLATION
930 help 464 help
931 This enables the Contiguous Memory A 465 This enables the Contiguous Memory Allocator which allows other
932 subsystems to allocate big physicall 466 subsystems to allocate big physically-contiguous blocks of memory.
933 CMA reserves a region of memory and 467 CMA reserves a region of memory and allows only movable pages to
934 be allocated from it. This way, the 468 be allocated from it. This way, the kernel can use the memory for
935 pagecache and when a subsystem reque 469 pagecache and when a subsystem requests for contiguous area, the
936 allocated pages are migrated away to 470 allocated pages are migrated away to serve the contiguous request.
937 471
938 If unsure, say "n". 472 If unsure, say "n".
939 473
>> 474 config CMA_DEBUG
>> 475 bool "CMA debug messages (DEVELOPMENT)"
>> 476 depends on DEBUG_KERNEL && CMA
>> 477 help
>> 478 Turns on debug messages in CMA. This produces KERN_DEBUG
>> 479 messages for every CMA call as well as various messages while
>> 480 processing calls such as dma_alloc_from_contiguous().
>> 481 This option does not affect warning and error messages.
>> 482
940 config CMA_DEBUGFS 483 config CMA_DEBUGFS
941 bool "CMA debugfs interface" 484 bool "CMA debugfs interface"
942 depends on CMA && DEBUG_FS 485 depends on CMA && DEBUG_FS
943 help 486 help
944 Turns on the DebugFS interface for C 487 Turns on the DebugFS interface for CMA.
945 488
946 config CMA_SYSFS 489 config CMA_SYSFS
947 bool "CMA information through sysfs in 490 bool "CMA information through sysfs interface"
948 depends on CMA && SYSFS 491 depends on CMA && SYSFS
949 help 492 help
950 This option exposes some sysfs attri 493 This option exposes some sysfs attributes to get information
951 from CMA. 494 from CMA.
952 495
953 config CMA_AREAS 496 config CMA_AREAS
954 int "Maximum count of the CMA areas" 497 int "Maximum count of the CMA areas"
955 depends on CMA 498 depends on CMA
956 default 20 if NUMA !! 499 default 19 if NUMA
957 default 8 !! 500 default 7
958 help 501 help
959 CMA allows to create CMA areas for p 502 CMA allows to create CMA areas for particular purpose, mainly,
960 used as device private area. This pa 503 used as device private area. This parameter sets the maximum
961 number of CMA area in the system. 504 number of CMA area in the system.
962 505
963 If unsure, leave the default value " !! 506 If unsure, leave the default value "7" in UMA and "19" in NUMA.
964 507
965 config MEM_SOFT_DIRTY 508 config MEM_SOFT_DIRTY
966 bool "Track memory changes" 509 bool "Track memory changes"
967 depends on CHECKPOINT_RESTORE && HAVE_ 510 depends on CHECKPOINT_RESTORE && HAVE_ARCH_SOFT_DIRTY && PROC_FS
968 select PROC_PAGE_MONITOR 511 select PROC_PAGE_MONITOR
969 help 512 help
970 This option enables memory changes t 513 This option enables memory changes tracking by introducing a
971 soft-dirty bit on pte-s. This bit it 514 soft-dirty bit on pte-s. This bit it set when someone writes
972 into a page just as regular dirty bi 515 into a page just as regular dirty bit, but unlike the latter
973 it can be cleared by hands. 516 it can be cleared by hands.
974 517
975 See Documentation/admin-guide/mm/sof 518 See Documentation/admin-guide/mm/soft-dirty.rst for more details.
976 519
>> 520 config ZSWAP
>> 521 bool "Compressed cache for swap pages (EXPERIMENTAL)"
>> 522 depends on SWAP && CRYPTO=y
>> 523 select FRONTSWAP
>> 524 select ZPOOL
>> 525 help
>> 526 A lightweight compressed cache for swap pages. It takes
>> 527 pages that are in the process of being swapped out and attempts to
>> 528 compress them into a dynamically allocated RAM-based memory pool.
>> 529 This can result in a significant I/O reduction on swap device and,
>> 530 in the case where decompressing from RAM is faster that swap device
>> 531 reads, can also improve workload performance.
>> 532
>> 533 This is marked experimental because it is a new feature (as of
>> 534 v3.11) that interacts heavily with memory reclaim. While these
>> 535 interactions don't cause any known issues on simple memory setups,
>> 536 they have not be fully explored on the large set of potential
>> 537 configurations and workloads that exist.
>> 538
>> 539 choice
>> 540 prompt "Compressed cache for swap pages default compressor"
>> 541 depends on ZSWAP
>> 542 default ZSWAP_COMPRESSOR_DEFAULT_LZO
>> 543 help
>> 544 Selects the default compression algorithm for the compressed cache
>> 545 for swap pages.
>> 546
>> 547 For an overview what kind of performance can be expected from
>> 548 a particular compression algorithm please refer to the benchmarks
>> 549 available at the following LWN page:
>> 550 https://lwn.net/Articles/751795/
>> 551
>> 552 If in doubt, select 'LZO'.
>> 553
>> 554 The selection made here can be overridden by using the kernel
>> 555 command line 'zswap.compressor=' option.
>> 556
>> 557 config ZSWAP_COMPRESSOR_DEFAULT_DEFLATE
>> 558 bool "Deflate"
>> 559 select CRYPTO_DEFLATE
>> 560 help
>> 561 Use the Deflate algorithm as the default compression algorithm.
>> 562
>> 563 config ZSWAP_COMPRESSOR_DEFAULT_LZO
>> 564 bool "LZO"
>> 565 select CRYPTO_LZO
>> 566 help
>> 567 Use the LZO algorithm as the default compression algorithm.
>> 568
>> 569 config ZSWAP_COMPRESSOR_DEFAULT_842
>> 570 bool "842"
>> 571 select CRYPTO_842
>> 572 help
>> 573 Use the 842 algorithm as the default compression algorithm.
>> 574
>> 575 config ZSWAP_COMPRESSOR_DEFAULT_LZ4
>> 576 bool "LZ4"
>> 577 select CRYPTO_LZ4
>> 578 help
>> 579 Use the LZ4 algorithm as the default compression algorithm.
>> 580
>> 581 config ZSWAP_COMPRESSOR_DEFAULT_LZ4HC
>> 582 bool "LZ4HC"
>> 583 select CRYPTO_LZ4HC
>> 584 help
>> 585 Use the LZ4HC algorithm as the default compression algorithm.
>> 586
>> 587 config ZSWAP_COMPRESSOR_DEFAULT_ZSTD
>> 588 bool "zstd"
>> 589 select CRYPTO_ZSTD
>> 590 help
>> 591 Use the zstd algorithm as the default compression algorithm.
>> 592 endchoice
>> 593
>> 594 config ZSWAP_COMPRESSOR_DEFAULT
>> 595 string
>> 596 depends on ZSWAP
>> 597 default "deflate" if ZSWAP_COMPRESSOR_DEFAULT_DEFLATE
>> 598 default "lzo" if ZSWAP_COMPRESSOR_DEFAULT_LZO
>> 599 default "842" if ZSWAP_COMPRESSOR_DEFAULT_842
>> 600 default "lz4" if ZSWAP_COMPRESSOR_DEFAULT_LZ4
>> 601 default "lz4hc" if ZSWAP_COMPRESSOR_DEFAULT_LZ4HC
>> 602 default "zstd" if ZSWAP_COMPRESSOR_DEFAULT_ZSTD
>> 603 default ""
>> 604
>> 605 choice
>> 606 prompt "Compressed cache for swap pages default allocator"
>> 607 depends on ZSWAP
>> 608 default ZSWAP_ZPOOL_DEFAULT_ZBUD
>> 609 help
>> 610 Selects the default allocator for the compressed cache for
>> 611 swap pages.
>> 612 The default is 'zbud' for compatibility, however please do
>> 613 read the description of each of the allocators below before
>> 614 making a right choice.
>> 615
>> 616 The selection made here can be overridden by using the kernel
>> 617 command line 'zswap.zpool=' option.
>> 618
>> 619 config ZSWAP_ZPOOL_DEFAULT_ZBUD
>> 620 bool "zbud"
>> 621 select ZBUD
>> 622 help
>> 623 Use the zbud allocator as the default allocator.
>> 624
>> 625 config ZSWAP_ZPOOL_DEFAULT_Z3FOLD
>> 626 bool "z3fold"
>> 627 select Z3FOLD
>> 628 help
>> 629 Use the z3fold allocator as the default allocator.
>> 630
>> 631 config ZSWAP_ZPOOL_DEFAULT_ZSMALLOC
>> 632 bool "zsmalloc"
>> 633 select ZSMALLOC
>> 634 help
>> 635 Use the zsmalloc allocator as the default allocator.
>> 636 endchoice
>> 637
>> 638 config ZSWAP_ZPOOL_DEFAULT
>> 639 string
>> 640 depends on ZSWAP
>> 641 default "zbud" if ZSWAP_ZPOOL_DEFAULT_ZBUD
>> 642 default "z3fold" if ZSWAP_ZPOOL_DEFAULT_Z3FOLD
>> 643 default "zsmalloc" if ZSWAP_ZPOOL_DEFAULT_ZSMALLOC
>> 644 default ""
>> 645
>> 646 config ZSWAP_DEFAULT_ON
>> 647 bool "Enable the compressed cache for swap pages by default"
>> 648 depends on ZSWAP
>> 649 help
>> 650 If selected, the compressed cache for swap pages will be enabled
>> 651 at boot, otherwise it will be disabled.
>> 652
>> 653 The selection made here can be overridden by using the kernel
>> 654 command line 'zswap.enabled=' option.
>> 655
>> 656 config ZPOOL
>> 657 tristate "Common API for compressed memory storage"
>> 658 help
>> 659 Compressed memory storage API. This allows using either zbud or
>> 660 zsmalloc.
>> 661
>> 662 config ZBUD
>> 663 tristate "Low (Up to 2x) density storage for compressed pages"
>> 664 depends on ZPOOL
>> 665 help
>> 666 A special purpose allocator for storing compressed pages.
>> 667 It is designed to store up to two compressed pages per physical
>> 668 page. While this design limits storage density, it has simple and
>> 669 deterministic reclaim properties that make it preferable to a higher
>> 670 density approach when reclaim will be used.
>> 671
>> 672 config Z3FOLD
>> 673 tristate "Up to 3x density storage for compressed pages"
>> 674 depends on ZPOOL
>> 675 help
>> 676 A special purpose allocator for storing compressed pages.
>> 677 It is designed to store up to three compressed pages per physical
>> 678 page. It is a ZBUD derivative so the simplicity and determinism are
>> 679 still there.
>> 680
>> 681 config ZSMALLOC
>> 682 tristate "Memory allocator for compressed pages"
>> 683 depends on MMU
>> 684 help
>> 685 zsmalloc is a slab-based memory allocator designed to store
>> 686 compressed RAM pages. zsmalloc uses virtual memory mapping
>> 687 in order to reduce fragmentation. However, this results in a
>> 688 non-standard allocator interface where a handle, not a pointer, is
>> 689 returned by an alloc(). This handle must be mapped in order to
>> 690 access the allocated space.
>> 691
>> 692 config ZSMALLOC_STAT
>> 693 bool "Export zsmalloc statistics"
>> 694 depends on ZSMALLOC
>> 695 select DEBUG_FS
>> 696 help
>> 697 This option enables code in the zsmalloc to collect various
>> 698 statistics about what's happening in zsmalloc and exports that
>> 699 information to userspace via debugfs.
>> 700 If unsure, say N.
>> 701
977 config GENERIC_EARLY_IOREMAP 702 config GENERIC_EARLY_IOREMAP
978 bool 703 bool
979 704
980 config STACK_MAX_DEFAULT_SIZE_MB 705 config STACK_MAX_DEFAULT_SIZE_MB
981 int "Default maximum user stack size f 706 int "Default maximum user stack size for 32-bit processes (MB)"
982 default 100 707 default 100
983 range 8 2048 708 range 8 2048
984 depends on STACK_GROWSUP && (!64BIT || 709 depends on STACK_GROWSUP && (!64BIT || COMPAT)
985 help 710 help
986 This is the maximum stack size in Me 711 This is the maximum stack size in Megabytes in the VM layout of 32-bit
987 user processes when the stack grows 712 user processes when the stack grows upwards (currently only on parisc
988 arch) when the RLIMIT_STACK hard lim 713 arch) when the RLIMIT_STACK hard limit is unlimited.
989 714
990 A sane initial value is 100 MB. 715 A sane initial value is 100 MB.
991 716
992 config DEFERRED_STRUCT_PAGE_INIT 717 config DEFERRED_STRUCT_PAGE_INIT
993 bool "Defer initialisation of struct p 718 bool "Defer initialisation of struct pages to kthreads"
994 depends on SPARSEMEM 719 depends on SPARSEMEM
995 depends on !NEED_PER_CPU_KM 720 depends on !NEED_PER_CPU_KM
996 depends on 64BIT 721 depends on 64BIT
997 depends on !KMSAN <<
998 select PADATA 722 select PADATA
999 help 723 help
1000 Ordinarily all struct pages are ini 724 Ordinarily all struct pages are initialised during early boot in a
1001 single thread. On very large machin 725 single thread. On very large machines this can take a considerable
1002 amount of time. If this option is s 726 amount of time. If this option is set, large machines will bring up
1003 a subset of memmap at boot and then 727 a subset of memmap at boot and then initialise the rest in parallel.
1004 This has a potential performance im 728 This has a potential performance impact on tasks running early in the
1005 lifetime of the system until these 729 lifetime of the system until these kthreads finish the
1006 initialisation. 730 initialisation.
1007 731
1008 config PAGE_IDLE_FLAG 732 config PAGE_IDLE_FLAG
1009 bool 733 bool
1010 select PAGE_EXTENSION if !64BIT 734 select PAGE_EXTENSION if !64BIT
1011 help 735 help
1012 This adds PG_idle and PG_young flag 736 This adds PG_idle and PG_young flags to 'struct page'. PTE Accessed
1013 bit writers can set the state of th 737 bit writers can set the state of the bit in the flags so that PTE
1014 Accessed bit readers may avoid dist 738 Accessed bit readers may avoid disturbance.
1015 739
1016 config IDLE_PAGE_TRACKING 740 config IDLE_PAGE_TRACKING
1017 bool "Enable idle page tracking" 741 bool "Enable idle page tracking"
1018 depends on SYSFS && MMU 742 depends on SYSFS && MMU
1019 select PAGE_IDLE_FLAG 743 select PAGE_IDLE_FLAG
1020 help 744 help
1021 This feature allows to estimate the 745 This feature allows to estimate the amount of user pages that have
1022 not been touched during a given per 746 not been touched during a given period of time. This information can
1023 be useful to tune memory cgroup lim 747 be useful to tune memory cgroup limits and/or for job placement
1024 within a compute cluster. 748 within a compute cluster.
1025 749
1026 See Documentation/admin-guide/mm/id 750 See Documentation/admin-guide/mm/idle_page_tracking.rst for
1027 more details. 751 more details.
1028 752
1029 # Architectures which implement cpu_dcache_is <<
1030 # whether the data caches are aliased (VIVT o <<
1031 # aliasing) need to select this. <<
1032 config ARCH_HAS_CPU_CACHE_ALIASING <<
1033 bool <<
1034 <<
1035 config ARCH_HAS_CACHE_LINE_SIZE 753 config ARCH_HAS_CACHE_LINE_SIZE
1036 bool 754 bool
1037 755
1038 config ARCH_HAS_CURRENT_STACK_POINTER 756 config ARCH_HAS_CURRENT_STACK_POINTER
1039 bool 757 bool
1040 help 758 help
1041 In support of HARDENED_USERCOPY per 759 In support of HARDENED_USERCOPY performing stack variable lifetime
1042 checking, an architecture-agnostic 760 checking, an architecture-agnostic way to find the stack pointer
1043 is needed. Once an architecture def 761 is needed. Once an architecture defines an unsigned long global
1044 register alias named "current_stack 762 register alias named "current_stack_pointer", this config can be
1045 selected. 763 selected.
1046 764
>> 765 config ARCH_HAS_FILTER_PGPROT
>> 766 bool
>> 767
1047 config ARCH_HAS_PTE_DEVMAP 768 config ARCH_HAS_PTE_DEVMAP
1048 bool 769 bool
1049 770
1050 config ARCH_HAS_ZONE_DMA_SET 771 config ARCH_HAS_ZONE_DMA_SET
1051 bool 772 bool
1052 773
1053 config ZONE_DMA 774 config ZONE_DMA
1054 bool "Support DMA zone" if ARCH_HAS_Z 775 bool "Support DMA zone" if ARCH_HAS_ZONE_DMA_SET
1055 default y if ARM64 || X86 776 default y if ARM64 || X86
1056 777
1057 config ZONE_DMA32 778 config ZONE_DMA32
1058 bool "Support DMA32 zone" if ARCH_HAS 779 bool "Support DMA32 zone" if ARCH_HAS_ZONE_DMA_SET
1059 depends on !X86_32 780 depends on !X86_32
1060 default y if ARM64 781 default y if ARM64
1061 782
1062 config ZONE_DEVICE 783 config ZONE_DEVICE
1063 bool "Device memory (pmem, HMM, etc.. 784 bool "Device memory (pmem, HMM, etc...) hotplug support"
1064 depends on MEMORY_HOTPLUG 785 depends on MEMORY_HOTPLUG
1065 depends on MEMORY_HOTREMOVE 786 depends on MEMORY_HOTREMOVE
1066 depends on SPARSEMEM_VMEMMAP 787 depends on SPARSEMEM_VMEMMAP
1067 depends on ARCH_HAS_PTE_DEVMAP 788 depends on ARCH_HAS_PTE_DEVMAP
1068 select XARRAY_MULTI 789 select XARRAY_MULTI
1069 790
1070 help 791 help
1071 Device memory hotplug support allow 792 Device memory hotplug support allows for establishing pmem,
1072 or other device driver discovered m 793 or other device driver discovered memory regions, in the
1073 memmap. This allows pfn_to_page() l 794 memmap. This allows pfn_to_page() lookups of otherwise
1074 "device-physical" addresses which i 795 "device-physical" addresses which is needed for using a DAX
1075 mapping in an O_DIRECT operation, a 796 mapping in an O_DIRECT operation, among other things.
1076 797
1077 If FS_DAX is enabled, then say Y. 798 If FS_DAX is enabled, then say Y.
1078 799
1079 # 800 #
1080 # Helpers to mirror range of the CPU page tab 801 # Helpers to mirror range of the CPU page tables of a process into device page
1081 # tables. 802 # tables.
1082 # 803 #
1083 config HMM_MIRROR 804 config HMM_MIRROR
1084 bool 805 bool
1085 depends on MMU 806 depends on MMU
1086 807
1087 config GET_FREE_REGION <<
1088 bool <<
1089 <<
1090 config DEVICE_PRIVATE 808 config DEVICE_PRIVATE
1091 bool "Unaddressable device memory (GP 809 bool "Unaddressable device memory (GPU memory, ...)"
1092 depends on ZONE_DEVICE 810 depends on ZONE_DEVICE
1093 select GET_FREE_REGION <<
1094 811
1095 help 812 help
1096 Allows creation of struct pages to 813 Allows creation of struct pages to represent unaddressable device
1097 memory; i.e., memory that is only a 814 memory; i.e., memory that is only accessible from the device (or
1098 group of devices). You likely also 815 group of devices). You likely also want to select HMM_MIRROR.
1099 816
1100 config VMAP_PFN 817 config VMAP_PFN
1101 bool 818 bool
1102 819
1103 config ARCH_USES_HIGH_VMA_FLAGS 820 config ARCH_USES_HIGH_VMA_FLAGS
1104 bool 821 bool
1105 config ARCH_HAS_PKEYS 822 config ARCH_HAS_PKEYS
1106 bool 823 bool
1107 824
1108 config ARCH_USES_PG_ARCH_2 <<
1109 bool <<
1110 config ARCH_USES_PG_ARCH_3 <<
1111 bool <<
1112 <<
1113 config VM_EVENT_COUNTERS <<
1114 default y <<
1115 bool "Enable VM event counters for /p <<
1116 help <<
1117 VM event counters are needed for ev <<
1118 This option allows the disabling of <<
1119 on EXPERT systems. /proc/vmstat wi <<
1120 if VM event counters are disabled. <<
1121 <<
1122 config PERCPU_STATS 825 config PERCPU_STATS
1123 bool "Collect percpu memory statistic 826 bool "Collect percpu memory statistics"
1124 help 827 help
1125 This feature collects and exposes s 828 This feature collects and exposes statistics via debugfs. The
1126 information includes global and per 829 information includes global and per chunk statistics, which can
1127 be used to help understand percpu m 830 be used to help understand percpu memory usage.
1128 831
1129 config GUP_TEST 832 config GUP_TEST
1130 bool "Enable infrastructure for get_u 833 bool "Enable infrastructure for get_user_pages()-related unit tests"
1131 depends on DEBUG_FS 834 depends on DEBUG_FS
1132 help 835 help
1133 Provides /sys/kernel/debug/gup_test 836 Provides /sys/kernel/debug/gup_test, which in turn provides a way
1134 to make ioctl calls that can launch 837 to make ioctl calls that can launch kernel-based unit tests for
1135 the get_user_pages*() and pin_user_ 838 the get_user_pages*() and pin_user_pages*() family of API calls.
1136 839
1137 These tests include benchmark testi 840 These tests include benchmark testing of the _fast variants of
1138 get_user_pages*() and pin_user_page 841 get_user_pages*() and pin_user_pages*(), as well as smoke tests of
1139 the non-_fast variants. 842 the non-_fast variants.
1140 843
1141 There is also a sub-test that allow 844 There is also a sub-test that allows running dump_page() on any
1142 of up to eight pages (selected by c 845 of up to eight pages (selected by command line args) within the
1143 range of user-space addresses. Thes 846 range of user-space addresses. These pages are either pinned via
1144 pin_user_pages*(), or pinned via ge 847 pin_user_pages*(), or pinned via get_user_pages*(), as specified
1145 by other command line arguments. 848 by other command line arguments.
1146 849
1147 See tools/testing/selftests/mm/gup_ !! 850 See tools/testing/selftests/vm/gup_test.c
1148 851
1149 comment "GUP_TEST needs to have DEBUG_FS enab 852 comment "GUP_TEST needs to have DEBUG_FS enabled"
1150 depends on !GUP_TEST && !DEBUG_FS 853 depends on !GUP_TEST && !DEBUG_FS
1151 854
1152 config GUP_GET_PXX_LOW_HIGH !! 855 config GUP_GET_PTE_LOW_HIGH
1153 bool 856 bool
1154 857
1155 config DMAPOOL_TEST !! 858 config READ_ONLY_THP_FOR_FS
1156 tristate "Enable a module to run time !! 859 bool "Read-only THP for filesystems (EXPERIMENTAL)"
1157 depends on HAS_DMA !! 860 depends on TRANSPARENT_HUGEPAGE && SHMEM
>> 861
1158 help 862 help
1159 Provides a test module that will al !! 863 Allow khugepaged to put read-only file-backed pages in THP.
1160 various sizes and report how long i !! 864
1161 provide a consistent way to measure !! 865 This is marked experimental because it is a new feature. Write
1162 dma_pool_alloc/free routines affect !! 866 support of file THPs will be developed in the next few release
>> 867 cycles.
1163 868
1164 config ARCH_HAS_PTE_SPECIAL 869 config ARCH_HAS_PTE_SPECIAL
1165 bool 870 bool
1166 871
>> 872 #
>> 873 # Some architectures require a special hugepage directory format that is
>> 874 # required to support multiple hugepage sizes. For example a4fe3ce76
>> 875 # "powerpc/mm: Allow more flexible layouts for hugepage pagetables"
>> 876 # introduced it on powerpc. This allows for a more flexible hugepage
>> 877 # pagetable layouts.
>> 878 #
>> 879 config ARCH_HAS_HUGEPD
>> 880 bool
>> 881
1167 config MAPPING_DIRTY_HELPERS 882 config MAPPING_DIRTY_HELPERS
1168 bool 883 bool
1169 884
1170 config KMAP_LOCAL 885 config KMAP_LOCAL
1171 bool 886 bool
1172 887
1173 config KMAP_LOCAL_NON_LINEAR_PTE_ARRAY 888 config KMAP_LOCAL_NON_LINEAR_PTE_ARRAY
1174 bool 889 bool
1175 890
1176 # struct io_mapping based helper. Selected b 891 # struct io_mapping based helper. Selected by drivers that need them
1177 config IO_MAPPING 892 config IO_MAPPING
1178 bool 893 bool
1179 894
1180 config MEMFD_CREATE <<
1181 bool "Enable memfd_create() system ca <<
1182 <<
1183 config SECRETMEM 895 config SECRETMEM
1184 default y !! 896 def_bool ARCH_HAS_SET_DIRECT_MAP && !EMBEDDED
1185 bool "Enable memfd_secret() system ca <<
1186 depends on ARCH_HAS_SET_DIRECT_MAP <<
1187 help <<
1188 Enable the memfd_secret() system ca <<
1189 memory areas visible only in the co <<
1190 not mapped to other processes and o <<
1191 897
1192 config ANON_VMA_NAME 898 config ANON_VMA_NAME
1193 bool "Anonymous VMA name support" 899 bool "Anonymous VMA name support"
1194 depends on PROC_FS && ADVISE_SYSCALLS 900 depends on PROC_FS && ADVISE_SYSCALLS && MMU
1195 901
1196 help 902 help
1197 Allow naming anonymous virtual memo 903 Allow naming anonymous virtual memory areas.
1198 904
1199 This feature allows assigning names 905 This feature allows assigning names to virtual memory areas. Assigned
1200 names can be later retrieved from / 906 names can be later retrieved from /proc/pid/maps and /proc/pid/smaps
1201 and help identifying individual ano 907 and help identifying individual anonymous memory areas.
1202 Assigning a name to anonymous virtu 908 Assigning a name to anonymous virtual memory area might prevent that
1203 area from being merged with adjacen 909 area from being merged with adjacent virtual memory areas due to the
1204 difference in their name. 910 difference in their name.
1205 <<
1206 config HAVE_ARCH_USERFAULTFD_WP <<
1207 bool <<
1208 help <<
1209 Arch has userfaultfd write protecti <<
1210 <<
1211 config HAVE_ARCH_USERFAULTFD_MINOR <<
1212 bool <<
1213 help <<
1214 Arch has userfaultfd minor fault su <<
1215 <<
1216 menuconfig USERFAULTFD <<
1217 bool "Enable userfaultfd() system cal <<
1218 depends on MMU <<
1219 help <<
1220 Enable the userfaultfd() system cal <<
1221 handle page faults in userland. <<
1222 <<
1223 if USERFAULTFD <<
1224 config PTE_MARKER_UFFD_WP <<
1225 bool "Userfaultfd write protection su <<
1226 default y <<
1227 depends on HAVE_ARCH_USERFAULTFD_WP <<
1228 <<
1229 help <<
1230 Allows to create marker PTEs for us <<
1231 purposes. It is required to enable <<
1232 file-backed memory types like shmem <<
1233 endif # USERFAULTFD <<
1234 <<
1235 # multi-gen LRU { <<
1236 config LRU_GEN <<
1237 bool "Multi-Gen LRU" <<
1238 depends on MMU <<
1239 # make sure folio->flags has enough s <<
1240 depends on 64BIT || !SPARSEMEM || SPA <<
1241 help <<
1242 A high performance LRU implementati <<
1243 Documentation/admin-guide/mm/multig <<
1244 <<
1245 config LRU_GEN_ENABLED <<
1246 bool "Enable by default" <<
1247 depends on LRU_GEN <<
1248 help <<
1249 This option enables the multi-gen L <<
1250 <<
1251 config LRU_GEN_STATS <<
1252 bool "Full stats for debugging" <<
1253 depends on LRU_GEN <<
1254 help <<
1255 Do not enable this option unless yo <<
1256 from evicted generations for debugg <<
1257 <<
1258 This option has a per-memcg and per <<
1259 <<
1260 config LRU_GEN_WALKS_MMU <<
1261 def_bool y <<
1262 depends on LRU_GEN && ARCH_HAS_HW_PTE <<
1263 # } <<
1264 <<
1265 config ARCH_SUPPORTS_PER_VMA_LOCK <<
1266 def_bool n <<
1267 <<
1268 config PER_VMA_LOCK <<
1269 def_bool y <<
1270 depends on ARCH_SUPPORTS_PER_VMA_LOCK <<
1271 help <<
1272 Allow per-vma locking during page f <<
1273 <<
1274 This feature allows locking each vi <<
1275 handling page faults instead of tak <<
1276 <<
1277 config LOCK_MM_AND_FIND_VMA <<
1278 bool <<
1279 depends on !STACK_GROWSUP <<
1280 <<
1281 config IOMMU_MM_DATA <<
1282 bool <<
1283 <<
1284 config EXECMEM <<
1285 bool <<
1286 <<
1287 config NUMA_MEMBLKS <<
1288 bool <<
1289 <<
1290 config NUMA_EMU <<
1291 bool "NUMA emulation" <<
1292 depends on NUMA_MEMBLKS <<
1293 help <<
1294 Enable NUMA emulation. A flat machi <<
1295 into virtual nodes when booted with <<
1296 number of nodes. This is only usefu <<
1297 911
1298 source "mm/damon/Kconfig" 912 source "mm/damon/Kconfig"
1299 913
1300 endmenu 914 endmenu
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