Commit | Line | Data |
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ec8f24b7 | 1 | # SPDX-License-Identifier: GPL-2.0-only |
59e0b520 CH |
2 | |
3 | menu "Memory Management options" | |
4 | ||
7b42f104 JW |
5 | # |
6 | # For some reason microblaze and nios2 hard code SWAP=n. Hopefully we can | |
7 | # add proper SWAP support to them, in which case this can be remove. | |
8 | # | |
9 | config ARCH_NO_SWAP | |
10 | bool | |
11 | ||
b3fbd58f JW |
12 | config ZPOOL |
13 | bool | |
14 | ||
519bcb79 | 15 | menuconfig SWAP |
7b42f104 JW |
16 | bool "Support for paging of anonymous memory (swap)" |
17 | depends on MMU && BLOCK && !ARCH_NO_SWAP | |
18 | default y | |
19 | help | |
20 | This option allows you to choose whether you want to have support | |
21 | for so called swap devices or swap files in your kernel that are | |
22 | used to provide more virtual memory than the actual RAM present | |
23 | in your computer. If unsure say Y. | |
24 | ||
519bcb79 | 25 | config ZSWAP |
fcab9b44 | 26 | bool "Compressed cache for swap pages" |
b3fbd58f | 27 | depends on SWAP |
b3fbd58f | 28 | select CRYPTO |
519bcb79 JW |
29 | select ZPOOL |
30 | help | |
31 | A lightweight compressed cache for swap pages. It takes | |
32 | pages that are in the process of being swapped out and attempts to | |
33 | compress them into a dynamically allocated RAM-based memory pool. | |
34 | This can result in a significant I/O reduction on swap device and, | |
1a44131d | 35 | in the case where decompressing from RAM is faster than swap device |
519bcb79 JW |
36 | reads, can also improve workload performance. |
37 | ||
b3fbd58f JW |
38 | config ZSWAP_DEFAULT_ON |
39 | bool "Enable the compressed cache for swap pages by default" | |
40 | depends on ZSWAP | |
41 | help | |
42 | If selected, the compressed cache for swap pages will be enabled | |
43 | at boot, otherwise it will be disabled. | |
44 | ||
45 | The selection made here can be overridden by using the kernel | |
46 | command line 'zswap.enabled=' option. | |
47 | ||
b9c91c43 YA |
48 | config ZSWAP_EXCLUSIVE_LOADS_DEFAULT_ON |
49 | bool "Invalidate zswap entries when pages are loaded" | |
50 | depends on ZSWAP | |
51 | help | |
52 | If selected, exclusive loads for zswap will be enabled at boot, | |
53 | otherwise it will be disabled. | |
54 | ||
55 | If exclusive loads are enabled, when a page is loaded from zswap, | |
56 | the zswap entry is invalidated at once, as opposed to leaving it | |
57 | in zswap until the swap entry is freed. | |
58 | ||
59 | This avoids having two copies of the same page in memory | |
60 | (compressed and uncompressed) after faulting in a page from zswap. | |
61 | The cost is that if the page was never dirtied and needs to be | |
62 | swapped out again, it will be re-compressed. | |
63 | ||
b5ba474f NP |
64 | config ZSWAP_SHRINKER_DEFAULT_ON |
65 | bool "Shrink the zswap pool on memory pressure" | |
66 | depends on ZSWAP | |
67 | default n | |
68 | help | |
69 | If selected, the zswap shrinker will be enabled, and the pages | |
70 | stored in the zswap pool will become available for reclaim (i.e | |
71 | written back to the backing swap device) on memory pressure. | |
72 | ||
73 | This means that zswap writeback could happen even if the pool is | |
74 | not yet full, or the cgroup zswap limit has not been reached, | |
75 | reducing the chance that cold pages will reside in the zswap pool | |
76 | and consume memory indefinitely. | |
77 | ||
519bcb79 | 78 | choice |
b3fbd58f | 79 | prompt "Default compressor" |
519bcb79 JW |
80 | depends on ZSWAP |
81 | default ZSWAP_COMPRESSOR_DEFAULT_LZO | |
82 | help | |
83 | Selects the default compression algorithm for the compressed cache | |
84 | for swap pages. | |
85 | ||
86 | For an overview what kind of performance can be expected from | |
87 | a particular compression algorithm please refer to the benchmarks | |
88 | available at the following LWN page: | |
89 | https://lwn.net/Articles/751795/ | |
90 | ||
91 | If in doubt, select 'LZO'. | |
92 | ||
93 | The selection made here can be overridden by using the kernel | |
94 | command line 'zswap.compressor=' option. | |
95 | ||
96 | config ZSWAP_COMPRESSOR_DEFAULT_DEFLATE | |
97 | bool "Deflate" | |
98 | select CRYPTO_DEFLATE | |
99 | help | |
100 | Use the Deflate algorithm as the default compression algorithm. | |
101 | ||
102 | config ZSWAP_COMPRESSOR_DEFAULT_LZO | |
103 | bool "LZO" | |
104 | select CRYPTO_LZO | |
105 | help | |
106 | Use the LZO algorithm as the default compression algorithm. | |
107 | ||
108 | config ZSWAP_COMPRESSOR_DEFAULT_842 | |
109 | bool "842" | |
110 | select CRYPTO_842 | |
111 | help | |
112 | Use the 842 algorithm as the default compression algorithm. | |
113 | ||
114 | config ZSWAP_COMPRESSOR_DEFAULT_LZ4 | |
115 | bool "LZ4" | |
116 | select CRYPTO_LZ4 | |
117 | help | |
118 | Use the LZ4 algorithm as the default compression algorithm. | |
119 | ||
120 | config ZSWAP_COMPRESSOR_DEFAULT_LZ4HC | |
121 | bool "LZ4HC" | |
122 | select CRYPTO_LZ4HC | |
123 | help | |
124 | Use the LZ4HC algorithm as the default compression algorithm. | |
125 | ||
126 | config ZSWAP_COMPRESSOR_DEFAULT_ZSTD | |
127 | bool "zstd" | |
128 | select CRYPTO_ZSTD | |
129 | help | |
130 | Use the zstd algorithm as the default compression algorithm. | |
131 | endchoice | |
132 | ||
133 | config ZSWAP_COMPRESSOR_DEFAULT | |
134 | string | |
135 | depends on ZSWAP | |
136 | default "deflate" if ZSWAP_COMPRESSOR_DEFAULT_DEFLATE | |
137 | default "lzo" if ZSWAP_COMPRESSOR_DEFAULT_LZO | |
138 | default "842" if ZSWAP_COMPRESSOR_DEFAULT_842 | |
139 | default "lz4" if ZSWAP_COMPRESSOR_DEFAULT_LZ4 | |
140 | default "lz4hc" if ZSWAP_COMPRESSOR_DEFAULT_LZ4HC | |
141 | default "zstd" if ZSWAP_COMPRESSOR_DEFAULT_ZSTD | |
142 | default "" | |
143 | ||
144 | choice | |
b3fbd58f | 145 | prompt "Default allocator" |
519bcb79 | 146 | depends on ZSWAP |
64d4d49c | 147 | default ZSWAP_ZPOOL_DEFAULT_ZSMALLOC if MMU |
519bcb79 JW |
148 | default ZSWAP_ZPOOL_DEFAULT_ZBUD |
149 | help | |
150 | Selects the default allocator for the compressed cache for | |
151 | swap pages. | |
152 | The default is 'zbud' for compatibility, however please do | |
153 | read the description of each of the allocators below before | |
154 | making a right choice. | |
155 | ||
156 | The selection made here can be overridden by using the kernel | |
157 | command line 'zswap.zpool=' option. | |
158 | ||
159 | config ZSWAP_ZPOOL_DEFAULT_ZBUD | |
160 | bool "zbud" | |
161 | select ZBUD | |
162 | help | |
163 | Use the zbud allocator as the default allocator. | |
164 | ||
165 | config ZSWAP_ZPOOL_DEFAULT_Z3FOLD | |
166 | bool "z3fold" | |
167 | select Z3FOLD | |
168 | help | |
169 | Use the z3fold allocator as the default allocator. | |
170 | ||
171 | config ZSWAP_ZPOOL_DEFAULT_ZSMALLOC | |
172 | bool "zsmalloc" | |
173 | select ZSMALLOC | |
174 | help | |
175 | Use the zsmalloc allocator as the default allocator. | |
176 | endchoice | |
177 | ||
178 | config ZSWAP_ZPOOL_DEFAULT | |
179 | string | |
180 | depends on ZSWAP | |
181 | default "zbud" if ZSWAP_ZPOOL_DEFAULT_ZBUD | |
182 | default "z3fold" if ZSWAP_ZPOOL_DEFAULT_Z3FOLD | |
183 | default "zsmalloc" if ZSWAP_ZPOOL_DEFAULT_ZSMALLOC | |
184 | default "" | |
185 | ||
519bcb79 | 186 | config ZBUD |
b3fbd58f JW |
187 | tristate "2:1 compression allocator (zbud)" |
188 | depends on ZSWAP | |
519bcb79 JW |
189 | help |
190 | A special purpose allocator for storing compressed pages. | |
191 | It is designed to store up to two compressed pages per physical | |
192 | page. While this design limits storage density, it has simple and | |
193 | deterministic reclaim properties that make it preferable to a higher | |
194 | density approach when reclaim will be used. | |
195 | ||
196 | config Z3FOLD | |
b3fbd58f JW |
197 | tristate "3:1 compression allocator (z3fold)" |
198 | depends on ZSWAP | |
519bcb79 JW |
199 | help |
200 | A special purpose allocator for storing compressed pages. | |
201 | It is designed to store up to three compressed pages per physical | |
202 | page. It is a ZBUD derivative so the simplicity and determinism are | |
203 | still there. | |
204 | ||
205 | config ZSMALLOC | |
b3fbd58f JW |
206 | tristate |
207 | prompt "N:1 compression allocator (zsmalloc)" if ZSWAP | |
519bcb79 JW |
208 | depends on MMU |
209 | help | |
210 | zsmalloc is a slab-based memory allocator designed to store | |
b3fbd58f JW |
211 | pages of various compression levels efficiently. It achieves |
212 | the highest storage density with the least amount of fragmentation. | |
519bcb79 JW |
213 | |
214 | config ZSMALLOC_STAT | |
215 | bool "Export zsmalloc statistics" | |
216 | depends on ZSMALLOC | |
217 | select DEBUG_FS | |
218 | help | |
219 | This option enables code in the zsmalloc to collect various | |
220 | statistics about what's happening in zsmalloc and exports that | |
221 | information to userspace via debugfs. | |
222 | If unsure, say N. | |
223 | ||
4ff93b29 SS |
224 | config ZSMALLOC_CHAIN_SIZE |
225 | int "Maximum number of physical pages per-zspage" | |
b46402fa | 226 | default 8 |
4ff93b29 SS |
227 | range 4 16 |
228 | depends on ZSMALLOC | |
229 | help | |
230 | This option sets the upper limit on the number of physical pages | |
231 | that a zmalloc page (zspage) can consist of. The optimal zspage | |
232 | chain size is calculated for each size class during the | |
233 | initialization of the pool. | |
234 | ||
235 | Changing this option can alter the characteristics of size classes, | |
236 | such as the number of pages per zspage and the number of objects | |
237 | per zspage. This can also result in different configurations of | |
238 | the pool, as zsmalloc merges size classes with similar | |
239 | characteristics. | |
240 | ||
241 | For more information, see zsmalloc documentation. | |
242 | ||
2a19be61 | 243 | menu "Slab allocator options" |
7b42f104 JW |
244 | |
245 | config SLUB | |
2a19be61 | 246 | def_bool y |
eb07c4f3 | 247 | |
e240e53a | 248 | config SLUB_TINY |
2a19be61 VB |
249 | bool "Configure for minimal memory footprint" |
250 | depends on EXPERT | |
e240e53a VB |
251 | select SLAB_MERGE_DEFAULT |
252 | help | |
2a19be61 | 253 | Configures the slab allocator in a way to achieve minimal memory |
e240e53a VB |
254 | footprint, sacrificing scalability, debugging and other features. |
255 | This is intended only for the smallest system that had used the | |
256 | SLOB allocator and is not recommended for systems with more than | |
257 | 16MB RAM. | |
258 | ||
259 | If unsure, say N. | |
260 | ||
7b42f104 JW |
261 | config SLAB_MERGE_DEFAULT |
262 | bool "Allow slab caches to be merged" | |
263 | default y | |
7b42f104 JW |
264 | help |
265 | For reduced kernel memory fragmentation, slab caches can be | |
266 | merged when they share the same size and other characteristics. | |
267 | This carries a risk of kernel heap overflows being able to | |
268 | overwrite objects from merged caches (and more easily control | |
269 | cache layout), which makes such heap attacks easier to exploit | |
270 | by attackers. By keeping caches unmerged, these kinds of exploits | |
271 | can usually only damage objects in the same cache. To disable | |
272 | merging at runtime, "slab_nomerge" can be passed on the kernel | |
273 | command line. | |
274 | ||
275 | config SLAB_FREELIST_RANDOM | |
276 | bool "Randomize slab freelist" | |
2a19be61 | 277 | depends on !SLUB_TINY |
7b42f104 JW |
278 | help |
279 | Randomizes the freelist order used on creating new pages. This | |
280 | security feature reduces the predictability of the kernel slab | |
281 | allocator against heap overflows. | |
282 | ||
283 | config SLAB_FREELIST_HARDENED | |
284 | bool "Harden slab freelist metadata" | |
2a19be61 | 285 | depends on !SLUB_TINY |
7b42f104 JW |
286 | help |
287 | Many kernel heap attacks try to target slab cache metadata and | |
288 | other infrastructure. This options makes minor performance | |
289 | sacrifices to harden the kernel slab allocator against common | |
2a19be61 | 290 | freelist exploit methods. |
7b42f104 | 291 | |
0710d012 VB |
292 | config SLUB_STATS |
293 | default n | |
2a19be61 VB |
294 | bool "Enable performance statistics" |
295 | depends on SYSFS && !SLUB_TINY | |
0710d012 | 296 | help |
2a19be61 | 297 | The statistics are useful to debug slab allocation behavior in |
0710d012 VB |
298 | order find ways to optimize the allocator. This should never be |
299 | enabled for production use since keeping statistics slows down | |
300 | the allocator by a few percentage points. The slabinfo command | |
301 | supports the determination of the most active slabs to figure | |
302 | out which slabs are relevant to a particular load. | |
303 | Try running: slabinfo -DA | |
304 | ||
519bcb79 JW |
305 | config SLUB_CPU_PARTIAL |
306 | default y | |
2a19be61 VB |
307 | depends on SMP && !SLUB_TINY |
308 | bool "Enable per cpu partial caches" | |
519bcb79 JW |
309 | help |
310 | Per cpu partial caches accelerate objects allocation and freeing | |
311 | that is local to a processor at the price of more indeterminism | |
312 | in the latency of the free. On overflow these caches will be cleared | |
313 | which requires the taking of locks that may cause latency spikes. | |
314 | Typically one would choose no for a realtime system. | |
315 | ||
3c615294 GR |
316 | config RANDOM_KMALLOC_CACHES |
317 | default n | |
2a19be61 | 318 | depends on !SLUB_TINY |
3c615294 GR |
319 | bool "Randomize slab caches for normal kmalloc" |
320 | help | |
321 | A hardening feature that creates multiple copies of slab caches for | |
322 | normal kmalloc allocation and makes kmalloc randomly pick one based | |
323 | on code address, which makes the attackers more difficult to spray | |
324 | vulnerable memory objects on the heap for the purpose of exploiting | |
325 | memory vulnerabilities. | |
326 | ||
327 | Currently the number of copies is set to 16, a reasonably large value | |
328 | that effectively diverges the memory objects allocated for different | |
329 | subsystems or modules into different caches, at the expense of a | |
330 | limited degree of memory and CPU overhead that relates to hardware and | |
331 | system workload. | |
332 | ||
2a19be61 | 333 | endmenu # Slab allocator options |
519bcb79 | 334 | |
7b42f104 JW |
335 | config SHUFFLE_PAGE_ALLOCATOR |
336 | bool "Page allocator randomization" | |
337 | default SLAB_FREELIST_RANDOM && ACPI_NUMA | |
338 | help | |
339 | Randomization of the page allocator improves the average | |
340 | utilization of a direct-mapped memory-side-cache. See section | |
341 | 5.2.27 Heterogeneous Memory Attribute Table (HMAT) in the ACPI | |
342 | 6.2a specification for an example of how a platform advertises | |
343 | the presence of a memory-side-cache. There are also incidental | |
344 | security benefits as it reduces the predictability of page | |
345 | allocations to compliment SLAB_FREELIST_RANDOM, but the | |
5e0a760b | 346 | default granularity of shuffling on the MAX_PAGE_ORDER i.e, 10th |
23baf831 KS |
347 | order of pages is selected based on cache utilization benefits |
348 | on x86. | |
7b42f104 JW |
349 | |
350 | While the randomization improves cache utilization it may | |
351 | negatively impact workloads on platforms without a cache. For | |
352 | this reason, by default, the randomization is enabled only | |
353 | after runtime detection of a direct-mapped memory-side-cache. | |
354 | Otherwise, the randomization may be force enabled with the | |
355 | 'page_alloc.shuffle' kernel command line parameter. | |
356 | ||
357 | Say Y if unsure. | |
358 | ||
0710d012 VB |
359 | config COMPAT_BRK |
360 | bool "Disable heap randomization" | |
361 | default y | |
362 | help | |
363 | Randomizing heap placement makes heap exploits harder, but it | |
364 | also breaks ancient binaries (including anything libc5 based). | |
365 | This option changes the bootup default to heap randomization | |
366 | disabled, and can be overridden at runtime by setting | |
367 | /proc/sys/kernel/randomize_va_space to 2. | |
368 | ||
369 | On non-ancient distros (post-2000 ones) N is usually a safe choice. | |
370 | ||
371 | config MMAP_ALLOW_UNINITIALIZED | |
372 | bool "Allow mmapped anonymous memory to be uninitialized" | |
373 | depends on EXPERT && !MMU | |
374 | default n | |
375 | help | |
376 | Normally, and according to the Linux spec, anonymous memory obtained | |
377 | from mmap() has its contents cleared before it is passed to | |
378 | userspace. Enabling this config option allows you to request that | |
379 | mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus | |
380 | providing a huge performance boost. If this option is not enabled, | |
381 | then the flag will be ignored. | |
382 | ||
383 | This is taken advantage of by uClibc's malloc(), and also by | |
384 | ELF-FDPIC binfmt's brk and stack allocator. | |
385 | ||
386 | Because of the obvious security issues, this option should only be | |
387 | enabled on embedded devices where you control what is run in | |
388 | userspace. Since that isn't generally a problem on no-MMU systems, | |
389 | it is normally safe to say Y here. | |
390 | ||
391 | See Documentation/admin-guide/mm/nommu-mmap.rst for more information. | |
392 | ||
e1785e85 DH |
393 | config SELECT_MEMORY_MODEL |
394 | def_bool y | |
a8826eeb | 395 | depends on ARCH_SELECT_MEMORY_MODEL |
e1785e85 | 396 | |
3a9da765 DH |
397 | choice |
398 | prompt "Memory model" | |
e1785e85 | 399 | depends on SELECT_MEMORY_MODEL |
d41dee36 | 400 | default SPARSEMEM_MANUAL if ARCH_SPARSEMEM_DEFAULT |
e1785e85 | 401 | default FLATMEM_MANUAL |
d66d109d MR |
402 | help |
403 | This option allows you to change some of the ways that | |
404 | Linux manages its memory internally. Most users will | |
405 | only have one option here selected by the architecture | |
406 | configuration. This is normal. | |
3a9da765 | 407 | |
e1785e85 | 408 | config FLATMEM_MANUAL |
3a9da765 | 409 | bool "Flat Memory" |
bb1c50d3 | 410 | depends on !ARCH_SPARSEMEM_ENABLE || ARCH_FLATMEM_ENABLE |
3a9da765 | 411 | help |
d66d109d MR |
412 | This option is best suited for non-NUMA systems with |
413 | flat address space. The FLATMEM is the most efficient | |
414 | system in terms of performance and resource consumption | |
415 | and it is the best option for smaller systems. | |
416 | ||
417 | For systems that have holes in their physical address | |
418 | spaces and for features like NUMA and memory hotplug, | |
dd33d29a | 419 | choose "Sparse Memory". |
d41dee36 AW |
420 | |
421 | If unsure, choose this option (Flat Memory) over any other. | |
3a9da765 | 422 | |
d41dee36 AW |
423 | config SPARSEMEM_MANUAL |
424 | bool "Sparse Memory" | |
425 | depends on ARCH_SPARSEMEM_ENABLE | |
426 | help | |
427 | This will be the only option for some systems, including | |
d66d109d | 428 | memory hot-plug systems. This is normal. |
d41dee36 | 429 | |
d66d109d MR |
430 | This option provides efficient support for systems with |
431 | holes is their physical address space and allows memory | |
432 | hot-plug and hot-remove. | |
d41dee36 | 433 | |
d66d109d | 434 | If unsure, choose "Flat Memory" over this option. |
d41dee36 | 435 | |
3a9da765 DH |
436 | endchoice |
437 | ||
d41dee36 AW |
438 | config SPARSEMEM |
439 | def_bool y | |
1a83e175 | 440 | depends on (!SELECT_MEMORY_MODEL && ARCH_SPARSEMEM_ENABLE) || SPARSEMEM_MANUAL |
d41dee36 | 441 | |
e1785e85 DH |
442 | config FLATMEM |
443 | def_bool y | |
bb1c50d3 | 444 | depends on !SPARSEMEM || FLATMEM_MANUAL |
d41dee36 | 445 | |
3e347261 BP |
446 | # |
447 | # SPARSEMEM_EXTREME (which is the default) does some bootmem | |
c89ab04f | 448 | # allocations when sparse_init() is called. If this cannot |
3e347261 BP |
449 | # be done on your architecture, select this option. However, |
450 | # statically allocating the mem_section[] array can potentially | |
451 | # consume vast quantities of .bss, so be careful. | |
452 | # | |
453 | # This option will also potentially produce smaller runtime code | |
454 | # with gcc 3.4 and later. | |
455 | # | |
456 | config SPARSEMEM_STATIC | |
9ba16087 | 457 | bool |
3e347261 | 458 | |
802f192e | 459 | # |
44c09201 | 460 | # Architecture platforms which require a two level mem_section in SPARSEMEM |
802f192e BP |
461 | # must select this option. This is usually for architecture platforms with |
462 | # an extremely sparse physical address space. | |
463 | # | |
3e347261 BP |
464 | config SPARSEMEM_EXTREME |
465 | def_bool y | |
466 | depends on SPARSEMEM && !SPARSEMEM_STATIC | |
4c21e2f2 | 467 | |
29c71111 | 468 | config SPARSEMEM_VMEMMAP_ENABLE |
9ba16087 | 469 | bool |
29c71111 AW |
470 | |
471 | config SPARSEMEM_VMEMMAP | |
a5ee6daa GL |
472 | bool "Sparse Memory virtual memmap" |
473 | depends on SPARSEMEM && SPARSEMEM_VMEMMAP_ENABLE | |
474 | default y | |
475 | help | |
19fa40a0 KK |
476 | SPARSEMEM_VMEMMAP uses a virtually mapped memmap to optimise |
477 | pfn_to_page and page_to_pfn operations. This is the most | |
478 | efficient option when sufficient kernel resources are available. | |
0b376f1e AK |
479 | # |
480 | # Select this config option from the architecture Kconfig, if it is preferred | |
481 | # to enable the feature of HugeTLB/dev_dax vmemmap optimization. | |
482 | # | |
0b6f1582 AK |
483 | config ARCH_WANT_OPTIMIZE_DAX_VMEMMAP |
484 | bool | |
485 | ||
486 | config ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP | |
0b376f1e | 487 | bool |
29c71111 | 488 | |
70210ed9 | 489 | config HAVE_MEMBLOCK_PHYS_MAP |
6341e62b | 490 | bool |
70210ed9 | 491 | |
67a929e0 | 492 | config HAVE_FAST_GUP |
050a9adc | 493 | depends on MMU |
6341e62b | 494 | bool |
2667f50e | 495 | |
52219aea DH |
496 | # Don't discard allocated memory used to track "memory" and "reserved" memblocks |
497 | # after early boot, so it can still be used to test for validity of memory. | |
498 | # Also, memblocks are updated with memory hot(un)plug. | |
350e88ba | 499 | config ARCH_KEEP_MEMBLOCK |
6341e62b | 500 | bool |
c378ddd5 | 501 | |
1e5d8e1e DW |
502 | # Keep arch NUMA mapping infrastructure post-init. |
503 | config NUMA_KEEP_MEMINFO | |
504 | bool | |
505 | ||
ee6f509c | 506 | config MEMORY_ISOLATION |
6341e62b | 507 | bool |
ee6f509c | 508 | |
a9e7b8d4 DH |
509 | # IORESOURCE_SYSTEM_RAM regions in the kernel resource tree that are marked |
510 | # IORESOURCE_EXCLUSIVE cannot be mapped to user space, for example, via | |
511 | # /dev/mem. | |
512 | config EXCLUSIVE_SYSTEM_RAM | |
513 | def_bool y | |
514 | depends on !DEVMEM || STRICT_DEVMEM | |
515 | ||
46723bfa YI |
516 | # |
517 | # Only be set on architectures that have completely implemented memory hotplug | |
518 | # feature. If you are not sure, don't touch it. | |
519 | # | |
520 | config HAVE_BOOTMEM_INFO_NODE | |
521 | def_bool n | |
522 | ||
91024b3c AK |
523 | config ARCH_ENABLE_MEMORY_HOTPLUG |
524 | bool | |
525 | ||
519bcb79 JW |
526 | config ARCH_ENABLE_MEMORY_HOTREMOVE |
527 | bool | |
528 | ||
3947be19 | 529 | # eventually, we can have this option just 'select SPARSEMEM' |
519bcb79 JW |
530 | menuconfig MEMORY_HOTPLUG |
531 | bool "Memory hotplug" | |
b30c5927 | 532 | select MEMORY_ISOLATION |
71b6f2dd | 533 | depends on SPARSEMEM |
40b31360 | 534 | depends on ARCH_ENABLE_MEMORY_HOTPLUG |
7ec58a2b | 535 | depends on 64BIT |
1e5d8e1e | 536 | select NUMA_KEEP_MEMINFO if NUMA |
3947be19 | 537 | |
519bcb79 JW |
538 | if MEMORY_HOTPLUG |
539 | ||
8604d9e5 | 540 | config MEMORY_HOTPLUG_DEFAULT_ONLINE |
19fa40a0 KK |
541 | bool "Online the newly added memory blocks by default" |
542 | depends on MEMORY_HOTPLUG | |
543 | help | |
8604d9e5 VK |
544 | This option sets the default policy setting for memory hotplug |
545 | onlining policy (/sys/devices/system/memory/auto_online_blocks) which | |
546 | determines what happens to newly added memory regions. Policy setting | |
547 | can always be changed at runtime. | |
cb1aaebe | 548 | See Documentation/admin-guide/mm/memory-hotplug.rst for more information. |
8604d9e5 VK |
549 | |
550 | Say Y here if you want all hot-plugged memory blocks to appear in | |
551 | 'online' state by default. | |
552 | Say N here if you want the default policy to keep all hot-plugged | |
553 | memory blocks in 'offline' state. | |
554 | ||
0c0e6195 KH |
555 | config MEMORY_HOTREMOVE |
556 | bool "Allow for memory hot remove" | |
f7e3334a | 557 | select HAVE_BOOTMEM_INFO_NODE if (X86_64 || PPC64) |
0c0e6195 KH |
558 | depends on MEMORY_HOTPLUG && ARCH_ENABLE_MEMORY_HOTREMOVE |
559 | depends on MIGRATION | |
560 | ||
a08a2ae3 OS |
561 | config MHP_MEMMAP_ON_MEMORY |
562 | def_bool y | |
563 | depends on MEMORY_HOTPLUG && SPARSEMEM_VMEMMAP | |
564 | depends on ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE | |
565 | ||
519bcb79 JW |
566 | endif # MEMORY_HOTPLUG |
567 | ||
04d5ea46 AK |
568 | config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE |
569 | bool | |
570 | ||
4c21e2f2 HD |
571 | # Heavily threaded applications may benefit from splitting the mm-wide |
572 | # page_table_lock, so that faults on different parts of the user address | |
573 | # space can be handled with less contention: split it at this NR_CPUS. | |
574 | # Default to 4 for wider testing, though 8 might be more appropriate. | |
575 | # ARM's adjust_pte (unused if VIPT) depends on mm-wide page_table_lock. | |
7b6ac9df | 576 | # PA-RISC 7xxx's spinlock_t would enlarge struct page from 32 to 44 bytes. |
60bccaa6 WD |
577 | # SPARC32 allocates multiple pte tables within a single page, and therefore |
578 | # a per-page lock leads to problems when multiple tables need to be locked | |
579 | # at the same time (e.g. copy_page_range()). | |
a70caa8b | 580 | # DEBUG_SPINLOCK and DEBUG_LOCK_ALLOC spinlock_t also enlarge struct page. |
4c21e2f2 HD |
581 | # |
582 | config SPLIT_PTLOCK_CPUS | |
583 | int | |
9164550e | 584 | default "999999" if !MMU |
a70caa8b HD |
585 | default "999999" if ARM && !CPU_CACHE_VIPT |
586 | default "999999" if PARISC && !PA20 | |
60bccaa6 | 587 | default "999999" if SPARC32 |
4c21e2f2 | 588 | default "4" |
7cbe34cf | 589 | |
e009bb30 | 590 | config ARCH_ENABLE_SPLIT_PMD_PTLOCK |
6341e62b | 591 | bool |
e009bb30 | 592 | |
09316c09 KK |
593 | # |
594 | # support for memory balloon | |
595 | config MEMORY_BALLOON | |
6341e62b | 596 | bool |
09316c09 | 597 | |
18468d93 RA |
598 | # |
599 | # support for memory balloon compaction | |
600 | config BALLOON_COMPACTION | |
601 | bool "Allow for balloon memory compaction/migration" | |
cd14b018 | 602 | default y |
09316c09 | 603 | depends on COMPACTION && MEMORY_BALLOON |
18468d93 RA |
604 | help |
605 | Memory fragmentation introduced by ballooning might reduce | |
606 | significantly the number of 2MB contiguous memory blocks that can be | |
607 | used within a guest, thus imposing performance penalties associated | |
608 | with the reduced number of transparent huge pages that could be used | |
609 | by the guest workload. Allowing the compaction & migration for memory | |
610 | pages enlisted as being part of memory balloon devices avoids the | |
611 | scenario aforementioned and helps improving memory defragmentation. | |
612 | ||
e9e96b39 MG |
613 | # |
614 | # support for memory compaction | |
615 | config COMPACTION | |
616 | bool "Allow for memory compaction" | |
cd14b018 | 617 | default y |
e9e96b39 | 618 | select MIGRATION |
33a93877 | 619 | depends on MMU |
e9e96b39 | 620 | help |
19fa40a0 KK |
621 | Compaction is the only memory management component to form |
622 | high order (larger physically contiguous) memory blocks | |
623 | reliably. The page allocator relies on compaction heavily and | |
624 | the lack of the feature can lead to unexpected OOM killer | |
625 | invocations for high order memory requests. You shouldn't | |
626 | disable this option unless there really is a strong reason for | |
627 | it and then we would be really interested to hear about that at | |
628 | linux-mm@kvack.org. | |
e9e96b39 | 629 | |
c7e0b3d0 TG |
630 | config COMPACT_UNEVICTABLE_DEFAULT |
631 | int | |
632 | depends on COMPACTION | |
633 | default 0 if PREEMPT_RT | |
634 | default 1 | |
635 | ||
36e66c55 AD |
636 | # |
637 | # support for free page reporting | |
638 | config PAGE_REPORTING | |
639 | bool "Free page reporting" | |
36e66c55 AD |
640 | help |
641 | Free page reporting allows for the incremental acquisition of | |
642 | free pages from the buddy allocator for the purpose of reporting | |
643 | those pages to another entity, such as a hypervisor, so that the | |
644 | memory can be freed within the host for other uses. | |
645 | ||
7cbe34cf CL |
646 | # |
647 | # support for page migration | |
648 | # | |
649 | config MIGRATION | |
b20a3503 | 650 | bool "Page migration" |
cd14b018 | 651 | default y |
de32a817 | 652 | depends on (NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE || COMPACTION || CMA) && MMU |
b20a3503 CL |
653 | help |
654 | Allows the migration of the physical location of pages of processes | |
e9e96b39 MG |
655 | while the virtual addresses are not changed. This is useful in |
656 | two situations. The first is on NUMA systems to put pages nearer | |
657 | to the processors accessing. The second is when allocating huge | |
658 | pages as migration can relocate pages to satisfy a huge page | |
659 | allocation instead of reclaiming. | |
6550e07f | 660 | |
76cbbead | 661 | config DEVICE_MIGRATION |
d90a25f8 | 662 | def_bool MIGRATION && ZONE_DEVICE |
76cbbead | 663 | |
c177c81e | 664 | config ARCH_ENABLE_HUGEPAGE_MIGRATION |
6341e62b | 665 | bool |
c177c81e | 666 | |
9c670ea3 NH |
667 | config ARCH_ENABLE_THP_MIGRATION |
668 | bool | |
669 | ||
4bfb68a0 AK |
670 | config HUGETLB_PAGE_SIZE_VARIABLE |
671 | def_bool n | |
672 | help | |
673 | Allows the pageblock_order value to be dynamic instead of just standard | |
674 | HUGETLB_PAGE_ORDER when there are multiple HugeTLB page sizes available | |
675 | on a platform. | |
676 | ||
5e0a760b KS |
677 | Note that the pageblock_order cannot exceed MAX_PAGE_ORDER and will be |
678 | clamped down to MAX_PAGE_ORDER. | |
b3d40a2b | 679 | |
8df995f6 | 680 | config CONTIG_ALLOC |
19fa40a0 | 681 | def_bool (MEMORY_ISOLATION && COMPACTION) || CMA |
8df995f6 | 682 | |
52166607 HY |
683 | config PCP_BATCH_SCALE_MAX |
684 | int "Maximum scale factor of PCP (Per-CPU pageset) batch allocate/free" | |
685 | default 5 | |
686 | range 0 6 | |
687 | help | |
688 | In page allocator, PCP (Per-CPU pageset) is refilled and drained in | |
689 | batches. The batch number is scaled automatically to improve page | |
690 | allocation/free throughput. But too large scale factor may hurt | |
691 | latency. This option sets the upper limit of scale factor to limit | |
692 | the maximum latency. | |
693 | ||
600715dc | 694 | config PHYS_ADDR_T_64BIT |
d4a451d5 | 695 | def_bool 64BIT |
600715dc | 696 | |
2a7326b5 | 697 | config BOUNCE |
9ca24e2e VM |
698 | bool "Enable bounce buffers" |
699 | default y | |
ce288e05 | 700 | depends on BLOCK && MMU && HIGHMEM |
9ca24e2e | 701 | help |
ce288e05 CH |
702 | Enable bounce buffers for devices that cannot access the full range of |
703 | memory available to the CPU. Enabled by default when HIGHMEM is | |
704 | selected, but you may say n to override this. | |
2a7326b5 | 705 | |
cddb8a5c AA |
706 | config MMU_NOTIFIER |
707 | bool | |
99cb252f | 708 | select INTERVAL_TREE |
fc4d5c29 | 709 | |
f8af4da3 HD |
710 | config KSM |
711 | bool "Enable KSM for page merging" | |
712 | depends on MMU | |
59e1a2f4 | 713 | select XXHASH |
f8af4da3 HD |
714 | help |
715 | Enable Kernel Samepage Merging: KSM periodically scans those areas | |
716 | of an application's address space that an app has advised may be | |
717 | mergeable. When it finds pages of identical content, it replaces | |
d0f209f6 | 718 | the many instances by a single page with that content, so |
f8af4da3 HD |
719 | saving memory until one or another app needs to modify the content. |
720 | Recommended for use with KVM, or with other duplicative applications. | |
ee65728e | 721 | See Documentation/mm/ksm.rst for more information: KSM is inactive |
c73602ad HD |
722 | until a program has madvised that an area is MADV_MERGEABLE, and |
723 | root has set /sys/kernel/mm/ksm/run to 1 (if CONFIG_SYSFS is set). | |
f8af4da3 | 724 | |
e0a94c2a | 725 | config DEFAULT_MMAP_MIN_ADDR |
19fa40a0 | 726 | int "Low address space to protect from user allocation" |
6e141546 | 727 | depends on MMU |
19fa40a0 KK |
728 | default 4096 |
729 | help | |
e0a94c2a CL |
730 | This is the portion of low virtual memory which should be protected |
731 | from userspace allocation. Keeping a user from writing to low pages | |
732 | can help reduce the impact of kernel NULL pointer bugs. | |
733 | ||
e99fb98d | 734 | For most ppc64 and x86 users with lots of address space |
e0a94c2a CL |
735 | a value of 65536 is reasonable and should cause no problems. |
736 | On arm and other archs it should not be higher than 32768. | |
788084ab EP |
737 | Programs which use vm86 functionality or have some need to map |
738 | this low address space will need CAP_SYS_RAWIO or disable this | |
739 | protection by setting the value to 0. | |
e0a94c2a CL |
740 | |
741 | This value can be changed after boot using the | |
742 | /proc/sys/vm/mmap_min_addr tunable. | |
743 | ||
d949f36f LT |
744 | config ARCH_SUPPORTS_MEMORY_FAILURE |
745 | bool | |
e0a94c2a | 746 | |
6a46079c AK |
747 | config MEMORY_FAILURE |
748 | depends on MMU | |
d949f36f | 749 | depends on ARCH_SUPPORTS_MEMORY_FAILURE |
6a46079c | 750 | bool "Enable recovery from hardware memory errors" |
ee6f509c | 751 | select MEMORY_ISOLATION |
97f0b134 | 752 | select RAS |
6a46079c AK |
753 | help |
754 | Enables code to recover from some memory failures on systems | |
755 | with MCA recovery. This allows a system to continue running | |
756 | even when some of its memory has uncorrected errors. This requires | |
757 | special hardware support and typically ECC memory. | |
758 | ||
cae681fc | 759 | config HWPOISON_INJECT |
413f9efb | 760 | tristate "HWPoison pages injector" |
27df5068 | 761 | depends on MEMORY_FAILURE && DEBUG_KERNEL && PROC_FS |
478c5ffc | 762 | select PROC_PAGE_MONITOR |
cae681fc | 763 | |
fc4d5c29 DH |
764 | config NOMMU_INITIAL_TRIM_EXCESS |
765 | int "Turn on mmap() excess space trimming before booting" | |
766 | depends on !MMU | |
767 | default 1 | |
768 | help | |
769 | The NOMMU mmap() frequently needs to allocate large contiguous chunks | |
770 | of memory on which to store mappings, but it can only ask the system | |
771 | allocator for chunks in 2^N*PAGE_SIZE amounts - which is frequently | |
772 | more than it requires. To deal with this, mmap() is able to trim off | |
773 | the excess and return it to the allocator. | |
774 | ||
775 | If trimming is enabled, the excess is trimmed off and returned to the | |
776 | system allocator, which can cause extra fragmentation, particularly | |
777 | if there are a lot of transient processes. | |
778 | ||
779 | If trimming is disabled, the excess is kept, but not used, which for | |
780 | long-term mappings means that the space is wasted. | |
781 | ||
782 | Trimming can be dynamically controlled through a sysctl option | |
783 | (/proc/sys/vm/nr_trim_pages) which specifies the minimum number of | |
784 | excess pages there must be before trimming should occur, or zero if | |
785 | no trimming is to occur. | |
786 | ||
787 | This option specifies the initial value of this option. The default | |
788 | of 1 says that all excess pages should be trimmed. | |
789 | ||
dd19d293 | 790 | See Documentation/admin-guide/mm/nommu-mmap.rst for more information. |
bbddff05 | 791 | |
519bcb79 JW |
792 | config ARCH_WANT_GENERAL_HUGETLB |
793 | bool | |
794 | ||
795 | config ARCH_WANTS_THP_SWAP | |
796 | def_bool n | |
797 | ||
798 | menuconfig TRANSPARENT_HUGEPAGE | |
13ece886 | 799 | bool "Transparent Hugepage Support" |
554b0f3c | 800 | depends on HAVE_ARCH_TRANSPARENT_HUGEPAGE && !PREEMPT_RT |
5d689240 | 801 | select COMPACTION |
3a08cd52 | 802 | select XARRAY_MULTI |
4c76d9d1 AA |
803 | help |
804 | Transparent Hugepages allows the kernel to use huge pages and | |
805 | huge tlb transparently to the applications whenever possible. | |
806 | This feature can improve computing performance to certain | |
807 | applications by speeding up page faults during memory | |
808 | allocation, by reducing the number of tlb misses and by speeding | |
809 | up the pagetable walking. | |
810 | ||
811 | If memory constrained on embedded, you may want to say N. | |
812 | ||
519bcb79 JW |
813 | if TRANSPARENT_HUGEPAGE |
814 | ||
13ece886 AA |
815 | choice |
816 | prompt "Transparent Hugepage Support sysfs defaults" | |
817 | depends on TRANSPARENT_HUGEPAGE | |
818 | default TRANSPARENT_HUGEPAGE_ALWAYS | |
819 | help | |
820 | Selects the sysfs defaults for Transparent Hugepage Support. | |
821 | ||
822 | config TRANSPARENT_HUGEPAGE_ALWAYS | |
823 | bool "always" | |
824 | help | |
825 | Enabling Transparent Hugepage always, can increase the | |
826 | memory footprint of applications without a guaranteed | |
827 | benefit but it will work automatically for all applications. | |
828 | ||
829 | config TRANSPARENT_HUGEPAGE_MADVISE | |
830 | bool "madvise" | |
831 | help | |
832 | Enabling Transparent Hugepage madvise, will only provide a | |
833 | performance improvement benefit to the applications using | |
834 | madvise(MADV_HUGEPAGE) but it won't risk to increase the | |
835 | memory footprint of applications without a guaranteed | |
836 | benefit. | |
683ec99f DM |
837 | |
838 | config TRANSPARENT_HUGEPAGE_NEVER | |
839 | bool "never" | |
840 | help | |
841 | Disable Transparent Hugepage by default. It can still be | |
842 | enabled at runtime via sysfs. | |
13ece886 AA |
843 | endchoice |
844 | ||
38d8b4e6 HY |
845 | config THP_SWAP |
846 | def_bool y | |
dad6a5eb | 847 | depends on TRANSPARENT_HUGEPAGE && ARCH_WANTS_THP_SWAP && SWAP && 64BIT |
38d8b4e6 HY |
848 | help |
849 | Swap transparent huge pages in one piece, without splitting. | |
14fef284 HY |
850 | XXX: For now, swap cluster backing transparent huge page |
851 | will be split after swapout. | |
38d8b4e6 HY |
852 | |
853 | For selection by architectures with reasonable THP sizes. | |
854 | ||
519bcb79 JW |
855 | config READ_ONLY_THP_FOR_FS |
856 | bool "Read-only THP for filesystems (EXPERIMENTAL)" | |
857 | depends on TRANSPARENT_HUGEPAGE && SHMEM | |
858 | ||
859 | help | |
860 | Allow khugepaged to put read-only file-backed pages in THP. | |
861 | ||
862 | This is marked experimental because it is a new feature. Write | |
863 | support of file THPs will be developed in the next few release | |
864 | cycles. | |
865 | ||
866 | endif # TRANSPARENT_HUGEPAGE | |
867 | ||
bbddff05 TH |
868 | # |
869 | # UP and nommu archs use km based percpu allocator | |
870 | # | |
871 | config NEED_PER_CPU_KM | |
3583521a | 872 | depends on !SMP || !MMU |
bbddff05 TH |
873 | bool |
874 | default y | |
077b1f83 | 875 | |
7ecd19cf KW |
876 | config NEED_PER_CPU_EMBED_FIRST_CHUNK |
877 | bool | |
878 | ||
879 | config NEED_PER_CPU_PAGE_FIRST_CHUNK | |
880 | bool | |
881 | ||
882 | config USE_PERCPU_NUMA_NODE_ID | |
883 | bool | |
884 | ||
885 | config HAVE_SETUP_PER_CPU_AREA | |
886 | bool | |
887 | ||
f825c736 AK |
888 | config CMA |
889 | bool "Contiguous Memory Allocator" | |
aca52c39 | 890 | depends on MMU |
f825c736 AK |
891 | select MIGRATION |
892 | select MEMORY_ISOLATION | |
893 | help | |
894 | This enables the Contiguous Memory Allocator which allows other | |
895 | subsystems to allocate big physically-contiguous blocks of memory. | |
896 | CMA reserves a region of memory and allows only movable pages to | |
897 | be allocated from it. This way, the kernel can use the memory for | |
898 | pagecache and when a subsystem requests for contiguous area, the | |
899 | allocated pages are migrated away to serve the contiguous request. | |
900 | ||
901 | If unsure, say "n". | |
902 | ||
903 | config CMA_DEBUG | |
904 | bool "CMA debug messages (DEVELOPMENT)" | |
905 | depends on DEBUG_KERNEL && CMA | |
906 | help | |
907 | Turns on debug messages in CMA. This produces KERN_DEBUG | |
908 | messages for every CMA call as well as various messages while | |
909 | processing calls such as dma_alloc_from_contiguous(). | |
910 | This option does not affect warning and error messages. | |
bf550fc9 | 911 | |
28b24c1f SL |
912 | config CMA_DEBUGFS |
913 | bool "CMA debugfs interface" | |
914 | depends on CMA && DEBUG_FS | |
915 | help | |
916 | Turns on the DebugFS interface for CMA. | |
917 | ||
43ca106f MK |
918 | config CMA_SYSFS |
919 | bool "CMA information through sysfs interface" | |
920 | depends on CMA && SYSFS | |
921 | help | |
922 | This option exposes some sysfs attributes to get information | |
923 | from CMA. | |
924 | ||
a254129e JK |
925 | config CMA_AREAS |
926 | int "Maximum count of the CMA areas" | |
927 | depends on CMA | |
b7176c26 | 928 | default 19 if NUMA |
a254129e JK |
929 | default 7 |
930 | help | |
931 | CMA allows to create CMA areas for particular purpose, mainly, | |
932 | used as device private area. This parameter sets the maximum | |
933 | number of CMA area in the system. | |
934 | ||
b7176c26 | 935 | If unsure, leave the default value "7" in UMA and "19" in NUMA. |
a254129e | 936 | |
af8d417a DS |
937 | config MEM_SOFT_DIRTY |
938 | bool "Track memory changes" | |
939 | depends on CHECKPOINT_RESTORE && HAVE_ARCH_SOFT_DIRTY && PROC_FS | |
940 | select PROC_PAGE_MONITOR | |
4e2e2770 | 941 | help |
af8d417a DS |
942 | This option enables memory changes tracking by introducing a |
943 | soft-dirty bit on pte-s. This bit it set when someone writes | |
944 | into a page just as regular dirty bit, but unlike the latter | |
945 | it can be cleared by hands. | |
946 | ||
1ad1335d | 947 | See Documentation/admin-guide/mm/soft-dirty.rst for more details. |
4e2e2770 | 948 | |
9e5c33d7 MS |
949 | config GENERIC_EARLY_IOREMAP |
950 | bool | |
042d27ac | 951 | |
22ee3ea5 HD |
952 | config STACK_MAX_DEFAULT_SIZE_MB |
953 | int "Default maximum user stack size for 32-bit processes (MB)" | |
954 | default 100 | |
042d27ac HD |
955 | range 8 2048 |
956 | depends on STACK_GROWSUP && (!64BIT || COMPAT) | |
957 | help | |
958 | This is the maximum stack size in Megabytes in the VM layout of 32-bit | |
959 | user processes when the stack grows upwards (currently only on parisc | |
22ee3ea5 | 960 | arch) when the RLIMIT_STACK hard limit is unlimited. |
042d27ac | 961 | |
22ee3ea5 | 962 | A sane initial value is 100 MB. |
3a80a7fa | 963 | |
3a80a7fa | 964 | config DEFERRED_STRUCT_PAGE_INIT |
1ce22103 | 965 | bool "Defer initialisation of struct pages to kthreads" |
d39f8fb4 | 966 | depends on SPARSEMEM |
ab1e8d89 | 967 | depends on !NEED_PER_CPU_KM |
889c695d | 968 | depends on 64BIT |
e4443149 | 969 | select PADATA |
3a80a7fa MG |
970 | help |
971 | Ordinarily all struct pages are initialised during early boot in a | |
972 | single thread. On very large machines this can take a considerable | |
973 | amount of time. If this option is set, large machines will bring up | |
e4443149 DJ |
974 | a subset of memmap at boot and then initialise the rest in parallel. |
975 | This has a potential performance impact on tasks running early in the | |
1ce22103 VB |
976 | lifetime of the system until these kthreads finish the |
977 | initialisation. | |
033fbae9 | 978 | |
1c676e0d SP |
979 | config PAGE_IDLE_FLAG |
980 | bool | |
981 | select PAGE_EXTENSION if !64BIT | |
982 | help | |
983 | This adds PG_idle and PG_young flags to 'struct page'. PTE Accessed | |
984 | bit writers can set the state of the bit in the flags so that PTE | |
985 | Accessed bit readers may avoid disturbance. | |
986 | ||
33c3fc71 VD |
987 | config IDLE_PAGE_TRACKING |
988 | bool "Enable idle page tracking" | |
989 | depends on SYSFS && MMU | |
1c676e0d | 990 | select PAGE_IDLE_FLAG |
33c3fc71 VD |
991 | help |
992 | This feature allows to estimate the amount of user pages that have | |
993 | not been touched during a given period of time. This information can | |
994 | be useful to tune memory cgroup limits and/or for job placement | |
995 | within a compute cluster. | |
996 | ||
1ad1335d MR |
997 | See Documentation/admin-guide/mm/idle_page_tracking.rst for |
998 | more details. | |
33c3fc71 | 999 | |
c2280be8 AK |
1000 | config ARCH_HAS_CACHE_LINE_SIZE |
1001 | bool | |
1002 | ||
2792d84e KC |
1003 | config ARCH_HAS_CURRENT_STACK_POINTER |
1004 | bool | |
1005 | help | |
1006 | In support of HARDENED_USERCOPY performing stack variable lifetime | |
1007 | checking, an architecture-agnostic way to find the stack pointer | |
1008 | is needed. Once an architecture defines an unsigned long global | |
1009 | register alias named "current_stack_pointer", this config can be | |
1010 | selected. | |
1011 | ||
17596731 | 1012 | config ARCH_HAS_PTE_DEVMAP |
65f7d049 OH |
1013 | bool |
1014 | ||
63703f37 KW |
1015 | config ARCH_HAS_ZONE_DMA_SET |
1016 | bool | |
1017 | ||
1018 | config ZONE_DMA | |
1019 | bool "Support DMA zone" if ARCH_HAS_ZONE_DMA_SET | |
1020 | default y if ARM64 || X86 | |
1021 | ||
1022 | config ZONE_DMA32 | |
1023 | bool "Support DMA32 zone" if ARCH_HAS_ZONE_DMA_SET | |
1024 | depends on !X86_32 | |
1025 | default y if ARM64 | |
1026 | ||
033fbae9 | 1027 | config ZONE_DEVICE |
5042db43 | 1028 | bool "Device memory (pmem, HMM, etc...) hotplug support" |
033fbae9 DW |
1029 | depends on MEMORY_HOTPLUG |
1030 | depends on MEMORY_HOTREMOVE | |
99490f16 | 1031 | depends on SPARSEMEM_VMEMMAP |
17596731 | 1032 | depends on ARCH_HAS_PTE_DEVMAP |
3a08cd52 | 1033 | select XARRAY_MULTI |
033fbae9 DW |
1034 | |
1035 | help | |
1036 | Device memory hotplug support allows for establishing pmem, | |
1037 | or other device driver discovered memory regions, in the | |
1038 | memmap. This allows pfn_to_page() lookups of otherwise | |
1039 | "device-physical" addresses which is needed for using a DAX | |
1040 | mapping in an O_DIRECT operation, among other things. | |
1041 | ||
1042 | If FS_DAX is enabled, then say Y. | |
06a660ad | 1043 | |
9c240a7b CH |
1044 | # |
1045 | # Helpers to mirror range of the CPU page tables of a process into device page | |
1046 | # tables. | |
1047 | # | |
c0b12405 | 1048 | config HMM_MIRROR |
9c240a7b | 1049 | bool |
f442c283 | 1050 | depends on MMU |
c0b12405 | 1051 | |
14b80582 DW |
1052 | config GET_FREE_REGION |
1053 | depends on SPARSEMEM | |
1054 | bool | |
1055 | ||
5042db43 JG |
1056 | config DEVICE_PRIVATE |
1057 | bool "Unaddressable device memory (GPU memory, ...)" | |
7328d9cc | 1058 | depends on ZONE_DEVICE |
14b80582 | 1059 | select GET_FREE_REGION |
5042db43 JG |
1060 | |
1061 | help | |
1062 | Allows creation of struct pages to represent unaddressable device | |
1063 | memory; i.e., memory that is only accessible from the device (or | |
1064 | group of devices). You likely also want to select HMM_MIRROR. | |
1065 | ||
3e9a9e25 CH |
1066 | config VMAP_PFN |
1067 | bool | |
1068 | ||
63c17fb8 DH |
1069 | config ARCH_USES_HIGH_VMA_FLAGS |
1070 | bool | |
66d37570 DH |
1071 | config ARCH_HAS_PKEYS |
1072 | bool | |
30a5b536 | 1073 | |
b0284cd2 CM |
1074 | config ARCH_USES_PG_ARCH_X |
1075 | bool | |
1076 | help | |
1077 | Enable the definition of PG_arch_x page flags with x > 1. Only | |
1078 | suitable for 64-bit architectures with CONFIG_FLATMEM or | |
1079 | CONFIG_SPARSEMEM_VMEMMAP enabled, otherwise there may not be | |
1080 | enough room for additional bits in page->flags. | |
1081 | ||
0710d012 VB |
1082 | config VM_EVENT_COUNTERS |
1083 | default y | |
1084 | bool "Enable VM event counters for /proc/vmstat" if EXPERT | |
1085 | help | |
1086 | VM event counters are needed for event counts to be shown. | |
1087 | This option allows the disabling of the VM event counters | |
1088 | on EXPERT systems. /proc/vmstat will only show page counts | |
1089 | if VM event counters are disabled. | |
1090 | ||
30a5b536 DZ |
1091 | config PERCPU_STATS |
1092 | bool "Collect percpu memory statistics" | |
30a5b536 DZ |
1093 | help |
1094 | This feature collects and exposes statistics via debugfs. The | |
1095 | information includes global and per chunk statistics, which can | |
1096 | be used to help understand percpu memory usage. | |
64c349f4 | 1097 | |
9c84f229 JH |
1098 | config GUP_TEST |
1099 | bool "Enable infrastructure for get_user_pages()-related unit tests" | |
d0de8241 | 1100 | depends on DEBUG_FS |
64c349f4 | 1101 | help |
9c84f229 JH |
1102 | Provides /sys/kernel/debug/gup_test, which in turn provides a way |
1103 | to make ioctl calls that can launch kernel-based unit tests for | |
1104 | the get_user_pages*() and pin_user_pages*() family of API calls. | |
64c349f4 | 1105 | |
9c84f229 JH |
1106 | These tests include benchmark testing of the _fast variants of |
1107 | get_user_pages*() and pin_user_pages*(), as well as smoke tests of | |
1108 | the non-_fast variants. | |
1109 | ||
f4f9bda4 JH |
1110 | There is also a sub-test that allows running dump_page() on any |
1111 | of up to eight pages (selected by command line args) within the | |
1112 | range of user-space addresses. These pages are either pinned via | |
1113 | pin_user_pages*(), or pinned via get_user_pages*(), as specified | |
1114 | by other command line arguments. | |
1115 | ||
baa489fa | 1116 | See tools/testing/selftests/mm/gup_test.c |
3010a5ea | 1117 | |
d0de8241 BS |
1118 | comment "GUP_TEST needs to have DEBUG_FS enabled" |
1119 | depends on !GUP_TEST && !DEBUG_FS | |
3010a5ea | 1120 | |
6ca297d4 | 1121 | config GUP_GET_PXX_LOW_HIGH |
39656e83 CH |
1122 | bool |
1123 | ||
def85743 KB |
1124 | config DMAPOOL_TEST |
1125 | tristate "Enable a module to run time tests on dma_pool" | |
1126 | depends on HAS_DMA | |
1127 | help | |
1128 | Provides a test module that will allocate and free many blocks of | |
1129 | various sizes and report how long it takes. This is intended to | |
1130 | provide a consistent way to measure how changes to the | |
1131 | dma_pool_alloc/free routines affect performance. | |
1132 | ||
3010a5ea LD |
1133 | config ARCH_HAS_PTE_SPECIAL |
1134 | bool | |
59e0b520 | 1135 | |
cbd34da7 CH |
1136 | # |
1137 | # Some architectures require a special hugepage directory format that is | |
1138 | # required to support multiple hugepage sizes. For example a4fe3ce76 | |
1139 | # "powerpc/mm: Allow more flexible layouts for hugepage pagetables" | |
1140 | # introduced it on powerpc. This allows for a more flexible hugepage | |
1141 | # pagetable layouts. | |
1142 | # | |
1143 | config ARCH_HAS_HUGEPD | |
1144 | bool | |
1145 | ||
c5acad84 TH |
1146 | config MAPPING_DIRTY_HELPERS |
1147 | bool | |
1148 | ||
298fa1ad TG |
1149 | config KMAP_LOCAL |
1150 | bool | |
1151 | ||
825c43f5 AB |
1152 | config KMAP_LOCAL_NON_LINEAR_PTE_ARRAY |
1153 | bool | |
1154 | ||
1fbaf8fc CH |
1155 | # struct io_mapping based helper. Selected by drivers that need them |
1156 | config IO_MAPPING | |
1157 | bool | |
1507f512 | 1158 | |
626e98cb TW |
1159 | config MEMFD_CREATE |
1160 | bool "Enable memfd_create() system call" if EXPERT | |
1161 | ||
1507f512 | 1162 | config SECRETMEM |
74947724 LB |
1163 | default y |
1164 | bool "Enable memfd_secret() system call" if EXPERT | |
1165 | depends on ARCH_HAS_SET_DIRECT_MAP | |
1166 | help | |
1167 | Enable the memfd_secret() system call with the ability to create | |
1168 | memory areas visible only in the context of the owning process and | |
1169 | not mapped to other processes and other kernel page tables. | |
1507f512 | 1170 | |
9a10064f CC |
1171 | config ANON_VMA_NAME |
1172 | bool "Anonymous VMA name support" | |
1173 | depends on PROC_FS && ADVISE_SYSCALLS && MMU | |
1174 | ||
1175 | help | |
1176 | Allow naming anonymous virtual memory areas. | |
1177 | ||
1178 | This feature allows assigning names to virtual memory areas. Assigned | |
1179 | names can be later retrieved from /proc/pid/maps and /proc/pid/smaps | |
1180 | and help identifying individual anonymous memory areas. | |
1181 | Assigning a name to anonymous virtual memory area might prevent that | |
1182 | area from being merged with adjacent virtual memory areas due to the | |
1183 | difference in their name. | |
1184 | ||
430529b5 PX |
1185 | config HAVE_ARCH_USERFAULTFD_WP |
1186 | bool | |
1187 | help | |
1188 | Arch has userfaultfd write protection support | |
1189 | ||
1190 | config HAVE_ARCH_USERFAULTFD_MINOR | |
1191 | bool | |
1192 | help | |
1193 | Arch has userfaultfd minor fault support | |
1194 | ||
97219cc3 PX |
1195 | menuconfig USERFAULTFD |
1196 | bool "Enable userfaultfd() system call" | |
1197 | depends on MMU | |
1198 | help | |
1199 | Enable the userfaultfd() system call that allows to intercept and | |
1200 | handle page faults in userland. | |
1201 | ||
1202 | if USERFAULTFD | |
1db9dbc2 | 1203 | config PTE_MARKER_UFFD_WP |
81e0f15f PX |
1204 | bool "Userfaultfd write protection support for shmem/hugetlbfs" |
1205 | default y | |
1206 | depends on HAVE_ARCH_USERFAULTFD_WP | |
1db9dbc2 PX |
1207 | |
1208 | help | |
1209 | Allows to create marker PTEs for userfaultfd write protection | |
1210 | purposes. It is required to enable userfaultfd write protection on | |
1211 | file-backed memory types like shmem and hugetlbfs. | |
97219cc3 | 1212 | endif # USERFAULTFD |
1db9dbc2 | 1213 | |
ac35a490 | 1214 | # multi-gen LRU { |
ec1c86b2 YZ |
1215 | config LRU_GEN |
1216 | bool "Multi-Gen LRU" | |
1217 | depends on MMU | |
1218 | # make sure folio->flags has enough spare bits | |
1219 | depends on 64BIT || !SPARSEMEM || SPARSEMEM_VMEMMAP | |
1220 | help | |
07017acb YZ |
1221 | A high performance LRU implementation to overcommit memory. See |
1222 | Documentation/admin-guide/mm/multigen_lru.rst for details. | |
ec1c86b2 | 1223 | |
354ed597 YZ |
1224 | config LRU_GEN_ENABLED |
1225 | bool "Enable by default" | |
1226 | depends on LRU_GEN | |
1227 | help | |
1228 | This option enables the multi-gen LRU by default. | |
1229 | ||
ac35a490 YZ |
1230 | config LRU_GEN_STATS |
1231 | bool "Full stats for debugging" | |
1232 | depends on LRU_GEN | |
1233 | help | |
1234 | Do not enable this option unless you plan to look at historical stats | |
1235 | from evicted generations for debugging purpose. | |
1236 | ||
1237 | This option has a per-memcg and per-node memory overhead. | |
61dd3f24 KH |
1238 | |
1239 | config LRU_GEN_WALKS_MMU | |
1240 | def_bool y | |
1241 | depends on LRU_GEN && ARCH_HAS_HW_PTE_YOUNG | |
ac35a490 YZ |
1242 | # } |
1243 | ||
0b6cc04f SB |
1244 | config ARCH_SUPPORTS_PER_VMA_LOCK |
1245 | def_bool n | |
1246 | ||
1247 | config PER_VMA_LOCK | |
1248 | def_bool y | |
1249 | depends on ARCH_SUPPORTS_PER_VMA_LOCK && MMU && SMP | |
1250 | help | |
1251 | Allow per-vma locking during page fault handling. | |
1252 | ||
1253 | This feature allows locking each virtual memory area separately when | |
1254 | handling page faults instead of taking mmap_lock. | |
1255 | ||
c2508ec5 LT |
1256 | config LOCK_MM_AND_FIND_VMA |
1257 | bool | |
1258 | depends on !STACK_GROWSUP | |
1259 | ||
8f23f5db JG |
1260 | config IOMMU_MM_DATA |
1261 | bool | |
1262 | ||
2224d848 SP |
1263 | source "mm/damon/Kconfig" |
1264 | ||
59e0b520 | 1265 | endmenu |