Lines Matching +full:default +full:- +full:on
1 # SPDX-License-Identifier: GPL-2.0-only
17 depends on MMU && BLOCK && !ARCH_NO_SWAP
18 default y
27 depends on SWAP
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,
39 bool "Enable the compressed cache for swap pages by default"
40 depends on ZSWAP
49 bool "Shrink the zswap pool on memory pressure"
50 depends on ZSWAP
51 default n
55 written back to the backing swap device) on memory pressure.
63 prompt "Default compressor"
64 depends on ZSWAP
65 default ZSWAP_COMPRESSOR_DEFAULT_LZO
67 Selects the default compression algorithm for the compressed cache
84 Use the Deflate algorithm as the default compression algorithm.
90 Use the LZO algorithm as the default compression algorithm.
96 Use the 842 algorithm as the default compression algorithm.
102 Use the LZ4 algorithm as the default compression algorithm.
108 Use the LZ4HC algorithm as the default compression algorithm.
114 Use the zstd algorithm as the default compression algorithm.
119 depends on ZSWAP
120 default "deflate" if ZSWAP_COMPRESSOR_DEFAULT_DEFLATE
121 default "lzo" if ZSWAP_COMPRESSOR_DEFAULT_LZO
122 default "842" if ZSWAP_COMPRESSOR_DEFAULT_842
123 default "lz4" if ZSWAP_COMPRESSOR_DEFAULT_LZ4
124 default "lz4hc" if ZSWAP_COMPRESSOR_DEFAULT_LZ4HC
125 default "zstd" if ZSWAP_COMPRESSOR_DEFAULT_ZSTD
126 default ""
129 prompt "Default allocator"
130 depends on ZSWAP
131 default ZSWAP_ZPOOL_DEFAULT_ZSMALLOC if MMU
132 default ZSWAP_ZPOOL_DEFAULT_ZBUD
134 Selects the default allocator for the compressed cache for
136 The default is 'zbud' for compatibility, however please do
147 Use the zbud allocator as the default allocator.
153 Use the z3fold allocator as the default allocator.
162 Use the zsmalloc allocator as the default allocator.
167 depends on ZSWAP
168 default "zbud" if ZSWAP_ZPOOL_DEFAULT_ZBUD
169 default "z3fold" if ZSWAP_ZPOOL_DEFAULT_Z3FOLD_DEPRECATED
170 default "zsmalloc" if ZSWAP_ZPOOL_DEFAULT_ZSMALLOC
171 default ""
175 depends on ZSWAP
185 depends on ZSWAP
189 linux-[email protected] and the zswap maintainers.
198 default y if Z3FOLD_DEPRECATED=y
199 default m if Z3FOLD_DEPRECATED=m
200 depends on Z3FOLD_DEPRECATED
205 depends on MMU
207 zsmalloc is a slab-based memory allocator designed to store
213 depends on ZSMALLOC
222 int "Maximum number of physical pages per-zspage"
223 default 8
225 depends on ZSMALLOC
227 This option sets the upper limit on the number of physical pages
247 depends on EXPERT
260 default y
269 merging at runtime, "slab_nomerge" can be passed on the kernel
274 depends on !SLUB_TINY
276 Randomizes the freelist order used on creating new pages. This
282 depends on !SLUB_TINY
291 depends on !SLUB_TINY
292 default SLAB_FREELIST_HARDENED
294 Kernel heap attacks frequently depend on being able to create
295 specifically-sized allocations with user-controlled contents
299 user-controlled allocations. This may very slightly increase
301 of extra pages since the bulk of user-controlled allocations
302 are relatively long-lived.
307 default n
309 depends on SYSFS && !SLUB_TINY
317 Try running: slabinfo -DA
320 default y
321 depends on SMP && !SLUB_TINY
326 in the latency of the free. On overflow these caches will be cleared
331 default n
332 depends on !SLUB_TINY
337 on code address, which makes the attackers more difficult to spray
338 vulnerable memory objects on the heap for the purpose of exploiting
351 default SLAB_FREELIST_RANDOM && ACPI_NUMA
354 utilization of a direct-mapped memory-side-cache. See section
357 the presence of a memory-side-cache. There are also incidental
360 default granularity of shuffling on the MAX_PAGE_ORDER i.e, 10th
361 order of pages is selected based on cache utilization benefits
362 on x86.
365 negatively impact workloads on platforms without a cache. For
366 this reason, by default, the randomization is not enabled even
374 default y
378 This option changes the bootup default to heap randomization
382 On non-ancient distros (post-2000 ones) N is usually a safe choice.
386 depends on EXPERT && !MMU
387 default n
397 ELF-FDPIC binfmt's brk and stack allocator.
400 enabled on embedded devices where you control what is run in
401 userspace. Since that isn't generally a problem on no-MMU systems,
404 See Documentation/admin-guide/mm/nommu-mmap.rst for more information.
408 depends on ARCH_SELECT_MEMORY_MODEL
412 depends on SELECT_MEMORY_MODEL
413 default SPARSEMEM_MANUAL if ARCH_SPARSEMEM_DEFAULT
414 default FLATMEM_MANUAL
423 depends on !ARCH_SPARSEMEM_ENABLE || ARCH_FLATMEM_ENABLE
425 This option is best suited for non-NUMA systems with
438 depends on ARCH_SPARSEMEM_ENABLE
441 memory hot-plug systems. This is normal.
445 hot-plug and hot-remove.
453 depends on (!SELECT_MEMORY_MODEL && ARCH_SPARSEMEM_ENABLE) || SPARSEMEM_MANUAL
457 depends on !SPARSEMEM || FLATMEM_MANUAL
460 # SPARSEMEM_EXTREME (which is the default) does some bootmem
462 # be done on your architecture, select this option. However,
479 depends on SPARSEMEM && !SPARSEMEM_STATIC
486 depends on SPARSEMEM && SPARSEMEM_VMEMMAP_ENABLE
487 default y
506 depends on MMU
515 # Keep arch NUMA mapping infrastructure post-init.
527 depends on !DEVMEM || STRICT_DEVMEM
530 # Only be set on architectures that have completely implemented memory hotplug
546 depends on SPARSEMEM
547 depends on ARCH_ENABLE_MEMORY_HOTPLUG
548 depends on 64BIT
554 prompt "Memory Hotplug Default Online Type"
555 default MHP_DEFAULT_ONLINE_TYPE_OFFLINE
557 Default memory type for hotplugged memory.
559 This option sets the default policy setting for memory hotplug
564 The default is 'offline'.
573 See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
578 Hotplugged memory will not be onlined by default.
606 sufficient kernel-capable memory (ZONE_NORMAL) must be
614 depends on MEMORY_HOTPLUG && ARCH_ENABLE_MEMORY_HOTREMOVE
615 depends on MIGRATION
619 depends on MEMORY_HOTPLUG && SPARSEMEM_VMEMMAP
620 depends on ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
627 # Heavily threaded applications may benefit from splitting the mm-wide
628 # page_table_lock, so that faults on different parts of the user address
630 # Default to 4 for wider testing, though 8 might be more appropriate.
631 # ARM's adjust_pte (unused if VIPT) depends on mm-wide page_table_lock.
632 # PA-RISC 7xxx's spinlock_t would enlarge struct page from 32 to 44 bytes.
634 # a per-page lock leads to problems when multiple tables need to be locked
640 depends on MMU
641 depends on SMP
642 depends on NR_CPUS >= 4
643 depends on !ARM || CPU_CACHE_VIPT
644 depends on !PARISC || PA20
645 depends on !SPARC32
652 depends on SPLIT_PTE_PTLOCKS && ARCH_ENABLE_SPLIT_PMD_PTLOCK
663 default y
664 depends on COMPACTION && MEMORY_BALLOON
678 default y
680 depends on MMU
684 reliably. The page allocator relies on compaction heavily and
689 linux-[email protected].
693 depends on COMPACTION
694 default 0 if PREEMPT_RT
695 default 1
712 default y
713 depends on (NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE || COMPACTION || CMA) && MMU
717 two situations. The first is on NUMA systems to put pages nearer
736 on a platform.
745 int "Maximum scale factor of PCP (Per-CPU pageset) batch allocate/free"
746 default 5
749 In page allocator, PCP (Per-CPU pageset) is refilled and drained in
760 default y
761 depends on BLOCK && MMU && HIGHMEM
764 memory available to the CPU. Enabled by default when HIGHMEM is
773 depends on MMU
788 depends on MMU
789 default 4096
797 On arm and other archs it should not be higher than 32768.
809 depends on MMU
810 depends on ARCH_SUPPORTS_MEMORY_FAILURE
815 Enables code to recover from some memory failures on systems
822 depends on MEMORY_FAILURE && DEBUG_KERNEL && PROC_FS
826 int "Turn on mmap() excess space trimming before booting"
827 depends on !MMU
828 default 1
831 of memory on which to store mappings, but it can only ask the system
832 allocator for chunks in 2^N*PAGE_SIZE amounts - which is frequently
841 long-term mappings means that the space is wasted.
848 This option specifies the initial value of this option. The default
851 See Documentation/admin-guide/mm/nommu-mmap.rst for more information.
861 depends on HAVE_ARCH_TRANSPARENT_HUGEPAGE && !PREEMPT_RT
872 If memory constrained on embedded, you may want to say N.
878 depends on TRANSPARENT_HUGEPAGE
879 default TRANSPARENT_HUGEPAGE_ALWAYS
902 Disable Transparent Hugepage by default. It can still be
908 depends on TRANSPARENT_HUGEPAGE && ARCH_WANTS_THP_SWAP && SWAP && 64BIT
917 bool "Read-only THP for filesystems (EXPERIMENTAL)"
918 depends on TRANSPARENT_HUGEPAGE && SHMEM
921 Allow khugepaged to put read-only file-backed pages in THP.
938 depends on TRANSPARENT_HUGEPAGE
942 depends on ARCH_SUPPORTS_HUGE_PFNMAP && HAVE_ARCH_TRANSPARENT_HUGEPAGE
946 depends on ARCH_SUPPORTS_HUGE_PFNMAP && HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
952 depends on !SMP || !MMU
954 default y
970 depends on MMU
975 subsystems to allocate big physically-contiguous blocks of memory.
985 depends on CMA && DEBUG_FS
987 Turns on the DebugFS interface for CMA.
991 depends on CMA && SYSFS
998 depends on CMA
999 default 20 if NUMA
1000 default 8
1006 If unsure, leave the default value "8" in UMA and "20" in NUMA.
1010 depends on CHECKPOINT_RESTORE && HAVE_ARCH_SOFT_DIRTY && PROC_FS
1014 soft-dirty bit on pte-s. This bit it set when someone writes
1018 See Documentation/admin-guide/mm/soft-dirty.rst for more details.
1024 int "Default maximum user stack size for 32-bit processes (MB)"
1025 default 100
1027 depends on STACK_GROWSUP && (!64BIT || COMPAT)
1029 This is the maximum stack size in Megabytes in the VM layout of 32-bit
1030 user processes when the stack grows upwards (currently only on parisc
1037 depends on SPARSEMEM
1038 depends on !NEED_PER_CPU_KM
1039 depends on 64BIT
1040 depends on !KMSAN
1044 single thread. On very large machines this can take a considerable
1047 This has a potential performance impact on tasks running early in the
1061 depends on SYSFS && MMU
1069 See Documentation/admin-guide/mm/idle_page_tracking.rst for
1085 checking, an architecture-agnostic way to find the stack pointer
1098 default y if ARM64 || X86
1102 depends on !X86_32
1103 default y if ARM64
1107 depends on MEMORY_HOTPLUG
1108 depends on MEMORY_HOTREMOVE
1109 depends on SPARSEMEM_VMEMMAP
1110 depends on ARCH_HAS_PTE_DEVMAP
1117 "device-physical" addresses which is needed for using a DAX
1128 depends on MMU
1135 depends on ZONE_DEVICE
1157 default y
1162 on EXPERT systems. /proc/vmstat will only show page counts
1173 bool "Enable infrastructure for get_user_pages()-related unit tests"
1174 depends on DEBUG_FS
1177 to make ioctl calls that can launch kernel-based unit tests for
1182 the non-_fast variants.
1184 There is also a sub-test that allows running dump_page() on any
1186 range of user-space addresses. These pages are either pinned via
1193 depends on !GUP_TEST && !DEBUG_FS
1199 tristate "Enable a module to run time tests on dma_pool"
1200 depends on HAS_DMA
1227 default y
1229 depends on ARCH_HAS_SET_DIRECT_MAP
1237 depends on PROC_FS && ADVISE_SYSCALLS && MMU
1261 depends on MMU
1269 default y
1270 depends on HAVE_ARCH_USERFAULTFD_WP
1274 purposes. It is required to enable userfaultfd write protection on
1275 file-backed memory types like shmem and hugetlbfs.
1278 # multi-gen LRU {
1280 bool "Multi-Gen LRU"
1281 depends on MMU
1282 # make sure folio->flags has enough spare bits
1283 depends on 64BIT || !SPARSEMEM || SPARSEMEM_VMEMMAP
1286 Documentation/admin-guide/mm/multigen_lru.rst for details.
1289 bool "Enable by default"
1290 depends on LRU_GEN
1292 This option enables the multi-gen LRU by default.
1296 depends on LRU_GEN
1301 This option has a per-memcg and per-node memory overhead.
1305 depends on LRU_GEN && ARCH_HAS_HW_PTE_YOUNG
1313 depends on ARCH_SUPPORTS_PER_VMA_LOCK && MMU && SMP
1315 Allow per-vma locking during page fault handling.
1322 depends on !STACK_GROWSUP
1335 depends on NUMA_MEMBLKS
1345 stacks (eg, x86 CET, arm64 GCS or RISC-V Zicfiss).
1352 default y
1353 depends on ARCH_SUPPORTS_PT_RECLAIM && MMU && SMP