1 # SPDX-License-Identifier: GPL-2.0-only
2
3 menu "Memory Management options"
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
407 def_bool y
408 depends on ARCH_SELECT_MEMORY_MODEL
409
410 choice
411 prompt "Memory model"
412 depends on SELECT_MEMORY_MODEL
413 default SPARSEMEM_MANUAL if ARCH_SPARS
414 default FLATMEM_MANUAL
415 help
416 This option allows you to change som
417 Linux manages its memory internally.
418 only have one option here selected b
419 configuration. This is normal.
420
421 config FLATMEM_MANUAL
422 bool "Flat Memory"
423 depends on !ARCH_SPARSEMEM_ENABLE || A
424 help
425 This option is best suited for non-N
426 flat address space. The FLATMEM is t
427 system in terms of performance and r
428 and it is the best option for smalle
429
430 For systems that have holes in their
431 spaces and for features like NUMA an
432 choose "Sparse Memory".
433
434 If unsure, choose this option (Flat
435
436 config SPARSEMEM_MANUAL
437 bool "Sparse Memory"
438 depends on ARCH_SPARSEMEM_ENABLE
439 help
440 This will be the only option for som
441 memory hot-plug systems. This is no
442
443 This option provides efficient suppo
444 holes is their physical address spac
445 hot-plug and hot-remove.
446
447 If unsure, choose "Flat Memory" over
448
449 endchoice
450
451 config SPARSEMEM
452 def_bool y
453 depends on (!SELECT_MEMORY_MODEL && AR
454
455 config FLATMEM
456 def_bool y
457 depends on !SPARSEMEM || FLATMEM_MANUA
458
459 #
460 # SPARSEMEM_EXTREME (which is the default) doe
461 # allocations when sparse_init() is called. I
462 # be done on your architecture, select this op
463 # statically allocating the mem_section[] arra
464 # consume vast quantities of .bss, so be caref
465 #
466 # This option will also potentially produce sm
467 # with gcc 3.4 and later.
468 #
469 config SPARSEMEM_STATIC
470 bool
471
472 #
473 # Architecture platforms which require a two l
474 # must select this option. This is usually for
475 # an extremely sparse physical address space.
476 #
477 config SPARSEMEM_EXTREME
478 def_bool y
479 depends on SPARSEMEM && !SPARSEMEM_STA
480
481 config SPARSEMEM_VMEMMAP_ENABLE
482 bool
483
484 config SPARSEMEM_VMEMMAP
485 bool "Sparse Memory virtual memmap"
486 depends on SPARSEMEM && SPARSEMEM_VMEM
487 default y
488 help
489 SPARSEMEM_VMEMMAP uses a virtually m
490 pfn_to_page and page_to_pfn operatio
491 efficient option when sufficient ker
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
502 config HAVE_MEMBLOCK_PHYS_MAP
503 bool
504
505 config HAVE_GUP_FAST
506 depends on MMU
507 bool
508
509 # Don't discard allocated memory used to track
510 # after early boot, so it can still be used to
511 # Also, memblocks are updated with memory hot(
512 config ARCH_KEEP_MEMBLOCK
513 bool
514
515 # Keep arch NUMA mapping infrastructure post-i
516 config NUMA_KEEP_MEMINFO
517 bool
518
519 config MEMORY_ISOLATION
520 bool
521
522 # IORESOURCE_SYSTEM_RAM regions in the kernel
523 # IORESOURCE_EXCLUSIVE cannot be mapped to use
524 # /dev/mem.
525 config EXCLUSIVE_SYSTEM_RAM
526 def_bool y
527 depends on !DEVMEM || STRICT_DEVMEM
528
529 #
530 # Only be set on architectures that have compl
531 # feature. If you are not sure, don't touch it
532 #
533 config HAVE_BOOTMEM_INFO_NODE
534 def_bool n
535
536 config ARCH_ENABLE_MEMORY_HOTPLUG
537 bool
538
539 config ARCH_ENABLE_MEMORY_HOTREMOVE
540 bool
541
542 # eventually, we can have this option just 'se
543 menuconfig MEMORY_HOTPLUG
544 bool "Memory hotplug"
545 select MEMORY_ISOLATION
546 depends on SPARSEMEM
547 depends on ARCH_ENABLE_MEMORY_HOTPLUG
548 depends on 64BIT
549 select NUMA_KEEP_MEMINFO if NUMA
550
551 if MEMORY_HOTPLUG
552
553 config MEMORY_HOTPLUG_DEFAULT_ONLINE
554 bool "Online the newly added memory bl
555 depends on MEMORY_HOTPLUG
556 help
557 This option sets the default policy
558 onlining policy (/sys/devices/system
559 determines what happens to newly add
560 can always be changed at runtime.
561 See Documentation/admin-guide/mm/mem
562
563 Say Y here if you want all hot-plugg
564 'online' state by default.
565 Say N here if you want the default p
566 memory blocks in 'offline' state.
567
568 config MEMORY_HOTREMOVE
569 bool "Allow for memory hot remove"
570 select HAVE_BOOTMEM_INFO_NODE if (X86_
571 depends on MEMORY_HOTPLUG && ARCH_ENAB
572 depends on MIGRATION
573
574 config MHP_MEMMAP_ON_MEMORY
575 def_bool y
576 depends on MEMORY_HOTPLUG && SPARSEMEM
577 depends on ARCH_MHP_MEMMAP_ON_MEMORY_E
578
579 endif # MEMORY_HOTPLUG
580
581 config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
582 bool
583
584 # Heavily threaded applications may benefit fr
585 # page_table_lock, so that faults on different
586 # space can be handled with less contention: s
587 # Default to 4 for wider testing, though 8 mig
588 # ARM's adjust_pte (unused if VIPT) depends on
589 # PA-RISC 7xxx's spinlock_t would enlarge stru
590 # SPARC32 allocates multiple pte tables within
591 # a per-page lock leads to problems when multi
592 # at the same time (e.g. copy_page_range()).
593 # DEBUG_SPINLOCK and DEBUG_LOCK_ALLOC spinlock
594 #
595 config SPLIT_PTE_PTLOCKS
596 def_bool y
597 depends on MMU
598 depends on SMP
599 depends on NR_CPUS >= 4
600 depends on !ARM || CPU_CACHE_VIPT
601 depends on !PARISC || PA20
602 depends on !SPARC32
603
604 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
605 bool
606
607 config SPLIT_PMD_PTLOCKS
608 def_bool y
609 depends on SPLIT_PTE_PTLOCKS && ARCH_E
610
611 #
612 # support for memory balloon
613 config MEMORY_BALLOON
614 bool
615
616 #
617 # support for memory balloon compaction
618 config BALLOON_COMPACTION
619 bool "Allow for balloon memory compact
620 default y
621 depends on COMPACTION && MEMORY_BALLOO
622 help
623 Memory fragmentation introduced by b
624 significantly the number of 2MB cont
625 used within a guest, thus imposing p
626 with the reduced number of transpare
627 by the guest workload. Allowing the
628 pages enlisted as being part of memo
629 scenario aforementioned and helps im
630
631 #
632 # support for memory compaction
633 config COMPACTION
634 bool "Allow for memory compaction"
635 default y
636 select MIGRATION
637 depends on MMU
638 help
639 Compaction is the only memory manage
640 high order (larger physically contig
641 reliably. The page allocator relies
642 the lack of the feature can lead to
643 invocations for high order memory re
644 disable this option unless there rea
645 it and then we would be really inter
646 linux-mm@kvack.org.
647
648 config COMPACT_UNEVICTABLE_DEFAULT
649 int
650 depends on COMPACTION
651 default 0 if PREEMPT_RT
652 default 1
653
654 #
655 # support for free page reporting
656 config PAGE_REPORTING
657 bool "Free page reporting"
658 help
659 Free page reporting allows for the i
660 free pages from the buddy allocator
661 those pages to another entity, such
662 memory can be freed within the host
663
664 #
665 # support for page migration
666 #
667 config MIGRATION
668 bool "Page migration"
669 default y
670 depends on (NUMA || ARCH_ENABLE_MEMORY
671 help
672 Allows the migration of the physical
673 while the virtual addresses are not
674 two situations. The first is on NUMA
675 to the processors accessing. The sec
676 pages as migration can relocate page
677 allocation instead of reclaiming.
678
679 config DEVICE_MIGRATION
680 def_bool MIGRATION && ZONE_DEVICE
681
682 config ARCH_ENABLE_HUGEPAGE_MIGRATION
683 bool
684
685 config ARCH_ENABLE_THP_MIGRATION
686 bool
687
688 config HUGETLB_PAGE_SIZE_VARIABLE
689 def_bool n
690 help
691 Allows the pageblock_order value to
692 HUGETLB_PAGE_ORDER when there are mu
693 on a platform.
694
695 Note that the pageblock_order cannot
696 clamped down to MAX_PAGE_ORDER.
697
698 config CONTIG_ALLOC
699 def_bool (MEMORY_ISOLATION && COMPACTI
700
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
713 def_bool 64BIT
714
715 config BOUNCE
716 bool "Enable bounce buffers"
717 default y
718 depends on BLOCK && MMU && HIGHMEM
719 help
720 Enable bounce buffers for devices th
721 memory available to the CPU. Enabled
722 selected, but you may say n to overr
723
724 config MMU_NOTIFIER
725 bool
726 select INTERVAL_TREE
727
728 config KSM
729 bool "Enable KSM for page merging"
730 depends on MMU
731 select XXHASH
732 help
733 Enable Kernel Samepage Merging: KSM
734 of an application's address space th
735 mergeable. When it finds pages of i
736 the many instances by a single page
737 saving memory until one or another a
738 Recommended for use with KVM, or wit
739 See Documentation/mm/ksm.rst for mor
740 until a program has madvised that an
741 root has set /sys/kernel/mm/ksm/run
742
743 config DEFAULT_MMAP_MIN_ADDR
744 int "Low address space to protect from
745 depends on MMU
746 default 4096
747 help
748 This is the portion of low virtual m
749 from userspace allocation. Keeping
750 can help reduce the impact of kernel
751
752 For most arm64, ppc64 and x86 users
753 a value of 65536 is reasonable and s
754 On arm and other archs it should not
755 Programs which use vm86 functionalit
756 this low address space will need CAP
757 protection by setting the value to 0
758
759 This value can be changed after boot
760 /proc/sys/vm/mmap_min_addr tunable.
761
762 config ARCH_SUPPORTS_MEMORY_FAILURE
763 bool
764
765 config MEMORY_FAILURE
766 depends on MMU
767 depends on ARCH_SUPPORTS_MEMORY_FAILUR
768 bool "Enable recovery from hardware me
769 select MEMORY_ISOLATION
770 select RAS
771 help
772 Enables code to recover from some me
773 with MCA recovery. This allows a sys
774 even when some of its memory has unc
775 special hardware support and typical
776
777 config HWPOISON_INJECT
778 tristate "HWPoison pages injector"
779 depends on MEMORY_FAILURE && DEBUG_KER
780 select PROC_PAGE_MONITOR
781
782 config NOMMU_INITIAL_TRIM_EXCESS
783 int "Turn on mmap() excess space trimm
784 depends on !MMU
785 default 1
786 help
787 The NOMMU mmap() frequently needs to
788 of memory on which to store mappings
789 allocator for chunks in 2^N*PAGE_SIZ
790 more than it requires. To deal with
791 the excess and return it to the allo
792
793 If trimming is enabled, the excess i
794 system allocator, which can cause ex
795 if there are a lot of transient proc
796
797 If trimming is disabled, the excess
798 long-term mappings means that the sp
799
800 Trimming can be dynamically controll
801 (/proc/sys/vm/nr_trim_pages) which s
802 excess pages there must be before tr
803 no trimming is to occur.
804
805 This option specifies the initial va
806 of 1 says that all excess pages shou
807
808 See Documentation/admin-guide/mm/nom
809
810 config ARCH_WANT_GENERAL_HUGETLB
811 bool
812
813 config ARCH_WANTS_THP_SWAP
814 def_bool n
815
816 menuconfig TRANSPARENT_HUGEPAGE
817 bool "Transparent Hugepage Support"
818 depends on HAVE_ARCH_TRANSPARENT_HUGEP
819 select COMPACTION
820 select XARRAY_MULTI
821 help
822 Transparent Hugepages allows the ker
823 huge tlb transparently to the applic
824 This feature can improve computing p
825 applications by speeding up page fau
826 allocation, by reducing the number o
827 up the pagetable walking.
828
829 If memory constrained on embedded, y
830
831 if TRANSPARENT_HUGEPAGE
832
833 choice
834 prompt "Transparent Hugepage Support s
835 depends on TRANSPARENT_HUGEPAGE
836 default TRANSPARENT_HUGEPAGE_ALWAYS
837 help
838 Selects the sysfs defaults for Trans
839
840 config TRANSPARENT_HUGEPAGE_ALWAYS
841 bool "always"
842 help
843 Enabling Transparent Hugepage always
844 memory footprint of applications wit
845 benefit but it will work automatical
846
847 config TRANSPARENT_HUGEPAGE_MADVISE
848 bool "madvise"
849 help
850 Enabling Transparent Hugepage madvis
851 performance improvement benefit to t
852 madvise(MADV_HUGEPAGE) but it won't
853 memory footprint of applications wit
854 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
862
863 config THP_SWAP
864 def_bool y
865 depends on TRANSPARENT_HUGEPAGE && ARC
866 help
867 Swap transparent huge pages in one p
868 XXX: For now, swap cluster backing t
869 will be split after swapout.
870
871 For selection by architectures with
872
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 #
906 # UP and nommu archs use km based percpu alloc
907 #
908 config NEED_PER_CPU_KM
909 depends on !SMP || !MMU
910 bool
911 default y
912
913 config NEED_PER_CPU_EMBED_FIRST_CHUNK
914 bool
915
916 config NEED_PER_CPU_PAGE_FIRST_CHUNK
917 bool
918
919 config USE_PERCPU_NUMA_NODE_ID
920 bool
921
922 config HAVE_SETUP_PER_CPU_AREA
923 bool
924
925 config CMA
926 bool "Contiguous Memory Allocator"
927 depends on MMU
928 select MIGRATION
929 select MEMORY_ISOLATION
930 help
931 This enables the Contiguous Memory A
932 subsystems to allocate big physicall
933 CMA reserves a region of memory and
934 be allocated from it. This way, the
935 pagecache and when a subsystem reque
936 allocated pages are migrated away to
937
938 If unsure, say "n".
939
940 config CMA_DEBUGFS
941 bool "CMA debugfs interface"
942 depends on CMA && DEBUG_FS
943 help
944 Turns on the DebugFS interface for C
945
946 config CMA_SYSFS
947 bool "CMA information through sysfs in
948 depends on CMA && SYSFS
949 help
950 This option exposes some sysfs attri
951 from CMA.
952
953 config CMA_AREAS
954 int "Maximum count of the CMA areas"
955 depends on CMA
956 default 20 if NUMA
957 default 8
958 help
959 CMA allows to create CMA areas for p
960 used as device private area. This pa
961 number of CMA area in the system.
962
963 If unsure, leave the default value "
964
965 config MEM_SOFT_DIRTY
966 bool "Track memory changes"
967 depends on CHECKPOINT_RESTORE && HAVE_
968 select PROC_PAGE_MONITOR
969 help
970 This option enables memory changes t
971 soft-dirty bit on pte-s. This bit it
972 into a page just as regular dirty bi
973 it can be cleared by hands.
974
975 See Documentation/admin-guide/mm/sof
976
977 config GENERIC_EARLY_IOREMAP
978 bool
979
980 config STACK_MAX_DEFAULT_SIZE_MB
981 int "Default maximum user stack size f
982 default 100
983 range 8 2048
984 depends on STACK_GROWSUP && (!64BIT ||
985 help
986 This is the maximum stack size in Me
987 user processes when the stack grows
988 arch) when the RLIMIT_STACK hard lim
989
990 A sane initial value is 100 MB.
991
992 config DEFERRED_STRUCT_PAGE_INIT
993 bool "Defer initialisation of struct p
994 depends on SPARSEMEM
995 depends on !NEED_PER_CPU_KM
996 depends on 64BIT
997 depends on !KMSAN
998 select PADATA
999 help
1000 Ordinarily all struct pages are ini
1001 single thread. On very large machin
1002 amount of time. If this option is s
1003 a subset of memmap at boot and then
1004 This has a potential performance im
1005 lifetime of the system until these
1006 initialisation.
1007
1008 config PAGE_IDLE_FLAG
1009 bool
1010 select PAGE_EXTENSION if !64BIT
1011 help
1012 This adds PG_idle and PG_young flag
1013 bit writers can set the state of th
1014 Accessed bit readers may avoid dist
1015
1016 config IDLE_PAGE_TRACKING
1017 bool "Enable idle page tracking"
1018 depends on SYSFS && MMU
1019 select PAGE_IDLE_FLAG
1020 help
1021 This feature allows to estimate the
1022 not been touched during a given per
1023 be useful to tune memory cgroup lim
1024 within a compute cluster.
1025
1026 See Documentation/admin-guide/mm/id
1027 more details.
1028
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
1036 bool
1037
1038 config ARCH_HAS_CURRENT_STACK_POINTER
1039 bool
1040 help
1041 In support of HARDENED_USERCOPY per
1042 checking, an architecture-agnostic
1043 is needed. Once an architecture def
1044 register alias named "current_stack
1045 selected.
1046
1047 config ARCH_HAS_PTE_DEVMAP
1048 bool
1049
1050 config ARCH_HAS_ZONE_DMA_SET
1051 bool
1052
1053 config ZONE_DMA
1054 bool "Support DMA zone" if ARCH_HAS_Z
1055 default y if ARM64 || X86
1056
1057 config ZONE_DMA32
1058 bool "Support DMA32 zone" if ARCH_HAS
1059 depends on !X86_32
1060 default y if ARM64
1061
1062 config ZONE_DEVICE
1063 bool "Device memory (pmem, HMM, etc..
1064 depends on MEMORY_HOTPLUG
1065 depends on MEMORY_HOTREMOVE
1066 depends on SPARSEMEM_VMEMMAP
1067 depends on ARCH_HAS_PTE_DEVMAP
1068 select XARRAY_MULTI
1069
1070 help
1071 Device memory hotplug support allow
1072 or other device driver discovered m
1073 memmap. This allows pfn_to_page() l
1074 "device-physical" addresses which i
1075 mapping in an O_DIRECT operation, a
1076
1077 If FS_DAX is enabled, then say Y.
1078
1079 #
1080 # Helpers to mirror range of the CPU page tab
1081 # tables.
1082 #
1083 config HMM_MIRROR
1084 bool
1085 depends on MMU
1086
1087 config GET_FREE_REGION
1088 bool
1089
1090 config DEVICE_PRIVATE
1091 bool "Unaddressable device memory (GP
1092 depends on ZONE_DEVICE
1093 select GET_FREE_REGION
1094
1095 help
1096 Allows creation of struct pages to
1097 memory; i.e., memory that is only a
1098 group of devices). You likely also
1099
1100 config VMAP_PFN
1101 bool
1102
1103 config ARCH_USES_HIGH_VMA_FLAGS
1104 bool
1105 config ARCH_HAS_PKEYS
1106 bool
1107
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
1123 bool "Collect percpu memory statistic
1124 help
1125 This feature collects and exposes s
1126 information includes global and per
1127 be used to help understand percpu m
1128
1129 config GUP_TEST
1130 bool "Enable infrastructure for get_u
1131 depends on DEBUG_FS
1132 help
1133 Provides /sys/kernel/debug/gup_test
1134 to make ioctl calls that can launch
1135 the get_user_pages*() and pin_user_
1136
1137 These tests include benchmark testi
1138 get_user_pages*() and pin_user_page
1139 the non-_fast variants.
1140
1141 There is also a sub-test that allow
1142 of up to eight pages (selected by c
1143 range of user-space addresses. Thes
1144 pin_user_pages*(), or pinned via ge
1145 by other command line arguments.
1146
1147 See tools/testing/selftests/mm/gup_
1148
1149 comment "GUP_TEST needs to have DEBUG_FS enab
1150 depends on !GUP_TEST && !DEBUG_FS
1151
1152 config GUP_GET_PXX_LOW_HIGH
1153 bool
1154
1155 config DMAPOOL_TEST
1156 tristate "Enable a module to run time
1157 depends on HAS_DMA
1158 help
1159 Provides a test module that will al
1160 various sizes and report how long i
1161 provide a consistent way to measure
1162 dma_pool_alloc/free routines affect
1163
1164 config ARCH_HAS_PTE_SPECIAL
1165 bool
1166
1167 config MAPPING_DIRTY_HELPERS
1168 bool
1169
1170 config KMAP_LOCAL
1171 bool
1172
1173 config KMAP_LOCAL_NON_LINEAR_PTE_ARRAY
1174 bool
1175
1176 # struct io_mapping based helper. Selected b
1177 config IO_MAPPING
1178 bool
1179
1180 config MEMFD_CREATE
1181 bool "Enable memfd_create() system ca
1182
1183 config SECRETMEM
1184 default y
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
1192 config ANON_VMA_NAME
1193 bool "Anonymous VMA name support"
1194 depends on PROC_FS && ADVISE_SYSCALLS
1195
1196 help
1197 Allow naming anonymous virtual memo
1198
1199 This feature allows assigning names
1200 names can be later retrieved from /
1201 and help identifying individual ano
1202 Assigning a name to anonymous virtu
1203 area from being merged with adjacen
1204 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
1298 source "mm/damon/Kconfig"
1299
1300 endmenu
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